Programs & Examples On #Indic

Indic scripts are the writing systems that are used by languages spoken by about two billion people in India and its neighboring countries, as well is Southeast Asian countries such as Thailand, Burma, Laos, Cambodia and Indonesia. These scripts developed from the ancient Brahmic script and share similar features, which make them challenging for use in computers: many ligatures, complex letter ordering rules and partial support in common operating systems.

need to add a class to an element

You can use result.className = 'red';, but you can also use result.classList.add('red');. The .classList.add(str) way is usually easier if you need to add a class in general, and don't want to check if the class is already in the list of classes.

Setting default checkbox value in Objective-C?

Documentation on UISwitch says:

[mySwitch setOn:NO]; 

In Interface Builder, select your switch and in the Attributes inspector you'll find State which can be set to on or off.

Speech input for visually impaired users without the need to tap the screen

The only way to get the iOS dictation is to sign up yourself through Nuance: http://dragonmobile.nuancemobiledeveloper.com/ - it's expensive, because it's the best. Presumably, Apple's contract prevents them from exposing an API.

The built in iOS accessibility features allow immobilized users to access dictation (and other keyboard buttons) through tools like VoiceOver and Assistive Touch. It may not be worth reinventing this if your users might be familiar with these tools.

500 Error on AppHarbor but downloaded build works on my machine

Just a wild guess: (not much to go on) but I have had similar problems when, for example, I was using the IIS rewrite module on my local machine (and it worked fine), but when I uploaded to a host that did not have that add-on module installed, I would get a 500 error with very little to go on - sounds similar. It drove me crazy trying to find it.

So make sure whatever options/addons that you might have and be using locally in IIS are also installed on the host.

Similarly, make sure you understand everything that is being referenced/used in your web.config - that is likely the problem area.

Can't perform a React state update on an unmounted component

To remove - Can't perform a React state update on an unmounted component warning, use componentDidMount method under a condition and make false that condition on componentWillUnmount method. For example : -

class Home extends Component {
  _isMounted = false;

  constructor(props) {
    super(props);

    this.state = {
      news: [],
    };
  }

  componentDidMount() {
    this._isMounted = true;

    ajaxVar
      .get('https://domain')
      .then(result => {
        if (this._isMounted) {
          this.setState({
            news: result.data.hits,
          });
        }
      });
  }

  componentWillUnmount() {
    this._isMounted = false;
  }

  render() {
    ...
  }
}

How to install OpenJDK 11 on Windows?

  1. Extract the zip file into a folder, e.g. C:\Program Files\Java\ and it will create a jdk-11 folder (where the bin folder is a direct sub-folder). You may need Administrator privileges to extract the zip file to this location.

  2. Set a PATH:

    • Select Control Panel and then System.
    • Click Advanced and then Environment Variables.
    • Add the location of the bin folder of the JDK installation to the PATH variable in System Variables.
    • The following is a typical value for the PATH variable: C:\WINDOWS\system32;C:\WINDOWS;"C:\Program Files\Java\jdk-11\bin"
  3. Set JAVA_HOME:

    • Under System Variables, click New.
    • Enter the variable name as JAVA_HOME.
    • Enter the variable value as the installation path of the JDK (without the bin sub-folder).
    • Click OK.
    • Click Apply Changes.
  4. Configure the JDK in your IDE (e.g. IntelliJ or Eclipse).

You are set.

To see if it worked, open up the Command Prompt and type java -version and see if it prints your newly installed JDK.

If you want to uninstall - just undo the above steps.

Note: You can also point JAVA_HOME to the folder of your JDK installations and then set the PATH variable to %JAVA_HOME%\bin. So when you want to change the JDK you change only the JAVA_HOME variable and leave PATH as it is.

Flutter - The method was called on null

As stated in the above answers, it's always a good practice to initialize the variables, but if you have something which you don't know what value should it takes, and you want to leave it uninitialized so you have to make sure that you are updating it before using it.

For example: Assume we have double _bmi; and you don't know what value should it takes, so you can leave it as it is, but before using it, you have to update its value first like calling a function that calculating BMI like follows:

String calculateBMI (){
_bmi = weight / pow( height/100, 2);
return _bmi.toStringAsFixed(1);}

or whatever, what I mean is, you can leave the variable as it is, but before using it make sure you have initialized it using whatever the method you are using.

What is the Record type in typescript?

A Record lets you create a new type from a Union. The values in the Union are used as attributes of the new type.

For example, say I have a Union like this:

type CatNames = "miffy" | "boris" | "mordred";

Now I want to create an object that contains information about all the cats, I can create a new type using the values in the CatName Union as keys.

type CatList = Record<CatNames, {age: number}>

If I want to satisfy this CatList, I must create an object like this:

const cats:CatList = {
  miffy: { age:99 },
  boris: { age:16 },
  mordred: { age:600 }
}

You get very strong type safety:

  • If I forget a cat, I get an error.
  • If I add a cat that's not allowed, I get an error.
  • If I later change CatNames, I get an error. This is especially useful because CatNames is likely imported from another file, and likely used in many places.

Real-world React example.

I used this recently to create a Status component. The component would receive a status prop, and then render an icon. I've simplified the code quite a lot here for illustrative purposes

I had a union like this:

type Statuses = "failed" | "complete";

I used this to create an object like this:

const icons: Record<
  Statuses,
  { iconType: IconTypes; iconColor: IconColors }
> = {
  failed: {
    iconType: "warning",
    iconColor: "red"
  },
  complete: {
    iconType: "check",
    iconColor: "green"
  };

I could then render by destructuring an element from the object into props, like so:

const Status = ({status}) => <Icon {...icons[status]} />

If the Statuses union is later extended or changed, I know my Status component will fail to compile and I'll get an error that I can fix immediately. This allows me to add additional error states to the app.

Note that the actual app had dozens of error states that were referenced in multiple places, so this type safety was extremely useful.

TypeError: only integer scalar arrays can be converted to a scalar index with 1D numpy indices array

Perhaps the error message is somewhat misleading, but the gist is that X_train is a list, not a numpy array. You cannot use array indexing on it. Make it an array first:

out_images = np.array(X_train)[indices.astype(int)]

Elasticsearch error: cluster_block_exception [FORBIDDEN/12/index read-only / allow delete (api)], flood stage disk watermark exceeded

Only changing the settings with the following command did not work in my environment:

curl -XPUT -H "Content-Type: application/json" http://localhost:9200/_all/_settings -d '{"index.blocks.read_only_allow_delete": null}'

I had to also ran the Force Merge API command:

curl -X POST "localhost:9200/my-index-000001/_forcemerge?pretty"

ref: Force Merge API

AttributeError: Module Pip has no attribute 'main'

For me this issue occured when I was running python while within my site-packages folder. If I ran it anywhere else, it was no longer an issue.

How to use lifecycle method getDerivedStateFromProps as opposed to componentWillReceiveProps

As we recently posted on the React blog, in the vast majority of cases you don't need getDerivedStateFromProps at all.

If you just want to compute some derived data, either:

  1. Do it right inside render
  2. Or, if re-calculating it is expensive, use a memoization helper like memoize-one.

Here's the simplest "after" example:

import memoize from "memoize-one";

class ExampleComponent extends React.Component {
  getDerivedData = memoize(computeDerivedState);

  render() {
    const derivedData = this.getDerivedData(this.props.someValue);
    // ...
  }
}

Check out this section of the blog post to learn more.

How to create number input field in Flutter?

Through this option you can strictly restricted another char with out number.

 inputFormatters: [FilteringTextInputFormatter.digitsOnly],
 keyboardType: TextInputType.number,

For using above option you have to import this

import 'package:flutter/services.dart';

using this kind of option user can not paste char in a textfield

How to clear Flutter's Build cache?

I was facing the same issue and i found out that I was having two terminals in visual studio code, On first terminal it was already running my flutter project and on the other terminal I was running different solutions shared in this thread. Due to this reason no solution was working for me. So there are two ways you can solve this problem. 1- Restart visual studio code (it will automatically close the terminals) 2- Stop the terminal in which flutter project is already running and then run flutter clean command.

Python convert object to float

I eventually used:

weather["Temp"] = weather["Temp"].convert_objects(convert_numeric=True)

It worked just fine, except that I got the following message.

C:\ProgramData\Anaconda3\lib\site-packages\ipykernel_launcher.py:3: FutureWarning:
convert_objects is deprecated.  Use the data-type specific converters pd.to_datetime, pd.to_timedelta and pd.to_numeric.

Your CPU supports instructions that this TensorFlow binary was not compiled to use: AVX AVX2

What is this warning about?

Modern CPUs provide a lot of low-level instructions, besides the usual arithmetic and logic, known as extensions, e.g. SSE2, SSE4, AVX, etc. From the Wikipedia:

Advanced Vector Extensions (AVX) are extensions to the x86 instruction set architecture for microprocessors from Intel and AMD proposed by Intel in March 2008 and first supported by Intel with the Sandy Bridge processor shipping in Q1 2011 and later on by AMD with the Bulldozer processor shipping in Q3 2011. AVX provides new features, new instructions and a new coding scheme.

In particular, AVX introduces fused multiply-accumulate (FMA) operations, which speed up linear algebra computation, namely dot-product, matrix multiply, convolution, etc. Almost every machine-learning training involves a great deal of these operations, hence will be faster on a CPU that supports AVX and FMA (up to 300%). The warning states that your CPU does support AVX (hooray!).

I'd like to stress here: it's all about CPU only.

Why isn't it used then?

Because tensorflow default distribution is built without CPU extensions, such as SSE4.1, SSE4.2, AVX, AVX2, FMA, etc. The default builds (ones from pip install tensorflow) are intended to be compatible with as many CPUs as possible. Another argument is that even with these extensions CPU is a lot slower than a GPU, and it's expected for medium- and large-scale machine-learning training to be performed on a GPU.

What should you do?

If you have a GPU, you shouldn't care about AVX support, because most expensive ops will be dispatched on a GPU device (unless explicitly set not to). In this case, you can simply ignore this warning by

# Just disables the warning, doesn't take advantage of AVX/FMA to run faster
import os
os.environ['TF_CPP_MIN_LOG_LEVEL'] = '2'

... or by setting export TF_CPP_MIN_LOG_LEVEL=2 if you're on Unix. Tensorflow is working fine anyway, but you won't see these annoying warnings.


If you don't have a GPU and want to utilize CPU as much as possible, you should build tensorflow from the source optimized for your CPU with AVX, AVX2, and FMA enabled if your CPU supports them. It's been discussed in this question and also this GitHub issue. Tensorflow uses an ad-hoc build system called bazel and building it is not that trivial, but is certainly doable. After this, not only will the warning disappear, tensorflow performance should also improve.

How to work with progress indicator in flutter?

Step 1: Create Dialog

   showAlertDialog(BuildContext context){
      AlertDialog alert=AlertDialog(
        content: new Row(
            children: [
               CircularProgressIndicator(),
               Container(margin: EdgeInsets.only(left: 5),child:Text("Loading" )),
            ],),
      );
      showDialog(barrierDismissible: false,
        context:context,
        builder:(BuildContext context){
          return alert;
        },
      );
    }

Step 2:Call it

showAlertDialog(context);
await firebaseAuth.signInWithEmailAndPassword(email: email, password: password);
Navigator.pop(context);

Example With Dialog and login form

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';
class DynamicLayout extends StatefulWidget{
  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    return new MyWidget();
    }
  }
showAlertDialog(BuildContext context){
  AlertDialog alert=AlertDialog(
    content: new Row(
        children: [
           CircularProgressIndicator(),
           Container(margin: EdgeInsets.only(left: 5),child:Text("Loading" )),
        ],),
  );
  showDialog(barrierDismissible: false,
    context:context,
    builder:(BuildContext context){
      return alert;
    },
  );
}

  class MyWidget extends State<DynamicLayout>{
  Color color = Colors.indigoAccent;
  String title='app';
  GlobalKey<FormState> globalKey=GlobalKey<FormState>();
  String email,password;
  login() async{
   var currentState= globalKey.currentState;
   if(currentState.validate()){
        currentState.save();
        FirebaseAuth firebaseAuth=FirebaseAuth.instance;
        try {
          showAlertDialog(context);
          AuthResult authResult=await firebaseAuth.signInWithEmailAndPassword(
              email: email, password: password);
          FirebaseUser user=authResult.user;
          Navigator.pop(context);
        }catch(e){
          print(e);
        }
   }else{

   }
  }
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
        appBar:AppBar(
        title: Text("$title"),
        ) ,
          body: Container(child: Form(
            key: globalKey,
            child: Container(
              padding: EdgeInsets.all(10),
              child: Column(children: <Widget>[
              TextFormField(decoration: InputDecoration(icon: Icon(Icons.email),labelText: 'Email'),
              // ignore: missing_return
              validator:(val){
                if(val.isEmpty)
                  return 'Please Enter Your Email';
              },
              onSaved:(val){
                email=val;
              },
              ),
                TextFormField(decoration: InputDecoration(icon: Icon(Icons.lock),labelText: 'Password'),
             obscureText: true,
                  // ignore: missing_return
                  validator:(val){
                    if(val.isEmpty)
                      return 'Please Enter Your Password';
                  },
                  onSaved:(val){
                    password=val;
                  },
              ),
                RaisedButton(color: Colors.lightBlue,textColor: Colors.white,child: Text('Login'),
                  onPressed:login),
            ],)
              ,),)
         ),
    );
  }
}

enter image description here

LabelEncoder: TypeError: '>' not supported between instances of 'float' and 'str'

As string data types have variable length, it is by default stored as object type. I faced this problem after treating missing values too. Converting all those columns to type 'category' before label encoding worked in my case.

df[cat]=df[cat].astype('category')

And then check df.dtypes and perform label encoding.

Change arrow colors in Bootstraps carousel

With Font Awesome icons:

<!-- Controls -->
<a class="carousel-control-prev" href="#carousel-example-generic" role="button" data-slide="prev">
  <span class="fa fa-chevron-left fa-lg" style="color:red;"></span>
  <span class="sr-only">Previous</span>
</a>
<a class="carousel-control-next" href="#carousel-example-generic" role="button" data-slide="next">
  <span class="fa fa-chevron-right fa-lg" style="color:red;"></span>
  <span class="sr-only">Next</span>
</a>

How can I dismiss the on screen keyboard?

None of the above solutions don't work for me.

Flutter suggests this - Put your widget inside new GestureDetector() on which tap will hide keyboard and onTap use FocusScope.of(context).requestFocus(new FocusNode())

class Home extends StatelessWidget {
@override
  Widget build(BuildContext context) {
    var widget = new MaterialApp(
        home: new Scaffold(
            body: new Container(
                height:500.0,
                child: new GestureDetector(
                    onTap: () {
                        FocusScope.of(context).requestFocus(new FocusNode());
                    },
                    child: new Container(
                        color: Colors.white,
                        child:  new Column(
                            mainAxisAlignment:  MainAxisAlignment.center,
                            crossAxisAlignment: CrossAxisAlignment.center,

                            children: [
                                new TextField( ),
                                new Text("Test"),                                
                            ],
                        )
                    )
                )
            )
        ),
    );

    return widget;
}}

Angular 2 ngfor first, last, index loop

Check out this plunkr.

When you're binding to variables, you need to use the brackets. Also, you use the hashtag when you want to get references to elements in your html, not for declaring variables inside of templates like that.

<md-button-toggle *ngFor="let indicador of indicadores; let first = first;" [value]="indicador.id" [checked]="first"> 
...

Edit: Thanks to Christopher Moore: Angular exposes the following local variables:

  • index
  • first
  • last
  • even
  • odd

TypeError: can't pickle _thread.lock objects

You need to change from queue import Queue to from multiprocessing import Queue.

The root reason is the former Queue is designed for threading module Queue while the latter is for multiprocessing.Process module.

For details, you can read some source code or contact me!

Java: How to resolve java.lang.NoClassDefFoundError: javax/xml/bind/JAXBException

The dependency versions that I needed to use when compiling for Java 8 target. Tested application in Java 8, 11, and 12 JREs.

        <!-- replace dependencies that have been removed from JRE's starting with Java v11 -->
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.2.8</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-core</artifactId>
            <version>2.2.8-b01</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-impl</artifactId>
            <version>2.2.8-b01</version>
        </dependency>
        <!-- end replace dependencies that have been removed from JRE's starting with Java v11 -->

How to call function on child component on parent events

You can use $emit and $on. Using @RoyJ code:

html:

<div id="app">
  <my-component></my-component>
  <button @click="click">Click</button>  
</div>

javascript:

var Child = {
  template: '<div>{{value}}</div>',
  data: function () {
    return {
      value: 0
    };
  },
  methods: {
    setValue: function(value) {
        this.value = value;
    }
  },
  created: function() {
    this.$parent.$on('update', this.setValue);
  }
}

new Vue({
  el: '#app',
  components: {
    'my-component': Child
  },
  methods: {
    click: function() {
        this.$emit('update', 7);
    }
  }
})

Running example: https://jsfiddle.net/rjurado/m2spy60r/1/

How do I get rid of the b-prefix in a string in python?

I got it done by only encoding the output using utf-8. Here is the code example

new_tweets = api.GetUserTimeline(screen_name = user,count=200)
result = new_tweets[0]
try: text = result.text
except: text = ''

with open(file_name, 'a', encoding='utf-8') as f:
    writer = csv.writer(f)
    writer.writerows(text)

i.e: do not encode when collecting data from api, encode the output (print or write) only.

pytest cannot import module while python can

Simply put an empty conftest.py file in the project root directory, because when pytest discovers a conftest.py, it modifies sys.path so it can import stuff from the conftest module. A general directory structure can be:

Root
+-- conftest.py
+-- module1
¦   +-- __init__.py
¦   +-- sample.py
+-- tests
    +-- test_sample.py

How to upgrade Angular CLI project?

According to the documentation on here http://angularjs.blogspot.co.uk/2017/03/angular-400-now-available.html you 'should' just be able to run...

npm install @angular/{common,compiler,compiler-cli,core,forms,http,platform-browser,platform-browser-dynamic,platform-server,router,animations}@latest typescript@latest --save

I tried it and got a couple of errors due to my zone.js and ngrx/store libraries being older versions.

Updating those to the latest versions npm install zone.js@latest --save and npm install @ngrx/store@latest -save, then running the angular install again worked for me.

Merge two dataframes by index

you can use concat([df1, df2, ...], axis=1) in order to concatenate two or more DFs aligned by indexes:

pd.concat([df1, df2, df3, ...], axis=1)

or merge for concatenating by custom fields / indexes:

# join by _common_ columns: `col1`, `col3`
pd.merge(df1, df2, on=['col1','col3'])

# join by: `df1.col1 == df2.index`
pd.merge(df1, df2, left_on='col1' right_index=True)

or join for joining by index:

 df1.join(df2)

docker cannot start on windows

if you are in windows try this

 docker-machine env --shell cmd default 
 @FOR /f "tokens=*" %i IN ('docker-machine env --shell cmd default') DO @%i

for testing try

docker run hello-world

ngModel cannot be used to register form controls with a parent formGroup directive

This error apears when you have some form controls (like Inputs, Selects, etc) in your form group tags with no formControlName property.

Those examples throws the error:

<form [formGroup]="myform">
    <input type="text">
    <input type="text" [ngmodel]="nameProperty">
    <input type="text" [formGroup]="myform" [name]="name">
</fom>

There are two ways, the stand alone:

<form [formGroup]="myform">
    <input type="text" [ngModelOptions]="{standalone: true}">
    <input type="text" [ngmodel]="nameProperty" [ngModelOptions]="{standalone: true}">
    <!-- input type="text" [formGroup]="myform" [name]="name" --> <!-- no works with standalone --
</form>

Or including it into the formgroup

<form [formGroup]="myform">
    <input type="text" formControlName="field1">
    <input type="text" formControlName="nameProperty">
    <input type="text" formControlName="name">
</fom>

The last one implies to define them in the initialization formGroup

this.myForm =  new FormGroup({
    field1: new FormControl(''),
    nameProperty: new FormControl(''),
    name: new FormControl('')
});

Angular2 RC5: Can't bind to 'Property X' since it isn't a known property of 'Child Component'

There are multiple possible causes for this error:

1) When you put the property 'x' inside brackets you are trying to bind to it. Therefore first thing to check is if the property 'x' is defined in your component with an Input() decorator

Your html file:

<body [x]="...">

Your class file:

export class YourComponentClass {

  @Input()
  x: string;
  ...
}

(make sure you also have the parentheses)

2) Make sure you registered your component/directive/pipe classes in NgModule:

@NgModule({
  ...
  declarations: [
    ...,
    YourComponentClass
  ],
  ...
})

See https://angular.io/guide/ngmodule#declare-directives for more details about declare directives.

3) Also happens if you have a typo in your angular directive. For example:

<div *ngif="...">
     ^^^^^

Instead of:

<div *ngIf="...">

This happens because under the hood angular converts the asterisk syntax to:

<div [ngIf]="...">

How to split data into 3 sets (train, validation and test)?

def train_val_test_split(X, y, train_size, val_size, test_size):
    X_train_val, X_test, y_train_val, y_test = train_test_split(X, y, test_size = test_size)
    relative_train_size = train_size / (val_size + train_size)
    X_train, X_val, y_train, y_val = train_test_split(X_train_val, y_train_val,
                                                      train_size = relative_train_size, test_size = 1-relative_train_size)
    return X_train, X_val, X_test, y_train, y_val, y_test

Here we split data 2 times with sklearn's train_test_split

Expected linebreaks to be 'LF' but found 'CRLF' linebreak-style

If you are using vscode I would recommend you to click the option at the bottom-right of the window and set it to LF from CRLF..this fixed my errors

How to get the indices list of all NaN value in numpy array?

Since x!=x returns the same boolean array with np.isnan(x) (because np.nan!=np.nan would return True), you could also write:

np.argwhere(x!=x)

However, I still recommend writing np.argwhere(np.isnan(x)) since it is more readable. I just try to provide another way to write the code in this answer.

org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:transformClassesWithDexForDebug'

Check build.gradle(Module: Android) fixed problem for me.

Modify it to workable version.

android {
    buildToolsVersion '23.0.1'
}

How to implement class constants?

Angular 2 Provides a very nice feature called as Opaque Constants. Create a class & Define all the constants there using opaque constants.

import { OpaqueToken } from "@angular/core";

export let APP_CONFIG = new OpaqueToken("my.config");

export interface MyAppConfig {
    apiEndpoint: string;
}

export const AppConfig: MyAppConfig = {    
    apiEndpoint: "http://localhost:8080/api/"    
};

Inject it in providers in app.module.ts

You will be able to use it across every components.

EDIT for Angular 4 :

For Angular 4 the new concept is Injection Token & Opaque token is Deprecated in Angular 4.

Injection Token Adds functionalities on top of Opaque Tokens, it allows to attach type info on the token via TypeScript generics, plus Injection tokens, removes the need of adding @Inject

Example Code

Angular 2 Using Opaque Tokens

const API_URL = new OpaqueToken('apiUrl'); //no Type Check


providers: [
  {
    provide: DataService,
    useFactory: (http, apiUrl) => {
      // create data service
    },
    deps: [
      Http,
      new Inject(API_URL) //notice the new Inject
    ]
  }
]

Angular 4 Using Injection Tokens

const API_URL = new InjectionToken<string>('apiUrl'); // generic defines return value of injector


providers: [
  {
    provide: DataService,
    useFactory: (http, apiUrl) => {
      // create data service
    },
    deps: [
      Http,
      API_URL // no `new Inject()` needed!
    ]
  }
]

Injection tokens are designed logically on top of Opaque tokens & Opaque tokens are deprecated in Angular 4.

How to get the dimensions of a tensor (in TensorFlow) at graph construction time?

I see most people confused about tf.shape(tensor) and tensor.get_shape() Let's make it clear:

  1. tf.shape

tf.shape is used for dynamic shape. If your tensor's shape is changable, use it. An example: a input is an image with changable width and height, we want resize it to half of its size, then we can write something like:
new_height = tf.shape(image)[0] / 2

  1. tensor.get_shape

tensor.get_shape is used for fixed shapes, which means the tensor's shape can be deduced in the graph.

Conclusion: tf.shape can be used almost anywhere, but t.get_shape only for shapes can be deduced from graph.

How to return history of validation loss in Keras

Another option is CSVLogger: https://keras.io/callbacks/#csvlogger. It creates a csv file appending the result of each epoch. Even if you interrupt training, you get to see how it evolved.

Removing legend on charts with chart.js v2

You simply need to add that line legend: { display: false }

Remove multiple items from a Python list in just one statement

But what if I don't know the indices of the items I want to remove?

I do not exactly understand why you do not like .remove but to get the first index corresponding to a value use .index(value):

ind=item_list.index('item')

then remove the corresponding value:

del item_list.pop[ind]

.index(value) gets the first occurrence of value, and .remove(value) removes the first occurrence of value

ReactJS - Add custom event listener to component

You could use componentDidMount and componentWillUnmount methods:

import React, { Component } from 'react';
import ReactDOM from 'react-dom';

class MovieItem extends Component
{
    _handleNVEvent = event => {
        ...
    };

    componentDidMount() {
        ReactDOM.findDOMNode(this).addEventListener('nv-event', this._handleNVEvent);
    }

    componentWillUnmount() {
        ReactDOM.findDOMNode(this).removeEventListener('nv-event', this._handleNVEvent);
    }

    [...]

}

export default MovieItem;

Google Maps API warning: NoApiKeys

I had the same problem and I found out that if you add the URL param ?v=3 you won't get the warning message anymore:

<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?v=3"></script>

Reproduction online

As pointed out in the comments by @Zia Ul Rehman Mughal

Turns out specifying this means you are referring to old frozen version 3.0 not the latest version. Frozen old versions are not updated with bug fixes or anything. But this is good to mention though. https://developers.google.com/maps/documentation/javascript/versions#the-frozen-version

Update 07-Jun-2016

This solution doesn't work anymore.

Android- Error:Execution failed for task ':app:transformClassesWithDexForRelease'

Add multiDexEnabled true in your defaultConfig in the app level gradle.

defaultConfig {
    applicationId "your application id"
    minSdkVersion 16
    targetSdkVersion 25
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner"android.support.test.runner.AndroidJUnitRunner"
    multiDexEnabled true
}

Create list of object from another using Java 8 Streams

An addition to the solution by @Rafael Teles. The syntactic sugar Collectors.mapping does the same in one step:

//...
List<Employee> employees = persons.stream()
  .filter(p -> p.getLastName().equals("l1"))
  .collect(
    Collectors.mapping(
      p -> new Employee(p.getName(), p.getLastName(), 1000),
      Collectors.toList()));

Detailed example can be found here

Change route params without reloading in Angular 2

Using location.go(url) is the way to go, but instead of hardcoding the url , consider generating it using router.createUrlTree().

Given that you want to do the following router call: this.router.navigate([{param: 1}], {relativeTo: this.activatedRoute}) but without reloading the component, it can be rewritten as:

const url = this.router.createUrlTree([], {relativeTo: this.activatedRoute, queryParams: {param: 1}}).toString()

 this.location.go(url);

How to use a client certificate to authenticate and authorize in a Web API

I came upon a similar issue recently and following Fabian's advice actually led me to the solution. Turns out with client certs you have to ensure two things:

  1. The private key is actually being exported as part of the cert.

  2. The application pool identity running the app has access to said private key.

In our case I had to:

  1. Import the pfx file into the local server store while checking the export checkbox to ensure the private key was sent out.
  2. Using MMC console, grant the service account used access to the private key for the cert.

The trusted root issue explained in other answers is a valid one, it was just not the issue in our case.

'dispatch' is not a function when argument to mapToDispatchToProps() in Redux

You are just missing the first argument to connect, which is the mapStateToProps method. Excerpt from the Redux todo app:

const mapStateToProps = (state) => {
  return {
    todos: getVisibleTodos(state.todos, state.visibilityFilter)
  }
}

const mapDispatchToProps = (dispatch) => {
  return {
    onTodoClick: (id) => {
      dispatch(toggleTodo(id))
    }
  }
}

const VisibleTodoList = connect(
  mapStateToProps,
  mapDispatchToProps
)(TodoList)

TypeError: tuple indices must be integers, not str

Like the error says, row is a tuple, so you can't do row["pool_number"]. You need to use the index: row[0].

only integers, slices (`:`), ellipsis (`...`), numpy.newaxis (`None`) and integer or boolean arrays are valid indices

I believe your problem is this: in your while loop, n is divided by 2, but never cast as an integer again, so it becomes a float at some point. It is then added onto y, which is then a float too, and that gives you the warning.

How to add header row to a pandas DataFrame

col_Names=["Sequence", "Start", "End", "Coverage"]
my_CSV_File= pd.read_csv("yourCSVFile.csv",names=col_Names)

having done this, just check it with[well obviously I know, u know that. But still...

my_CSV_File.head()

Hope it helps ... Cheers

Postman - How to see request with headers and body data with variables substituted

As of now, Postman comes with its own "Console." Click the terminal-like icon on the bottom left to open the console. Send a request, and you can inspect the request from within Postman's console.

enter image description here

TypeError: list indices must be integers or slices, not str

First, array_length should be an integer and not a string:

array_length = len(array_dates)

Second, your for loop should be constructed using range:

for i in range(array_length):  # Use `xrange` for python 2.

Third, i will increment automatically, so delete the following line:

i += 1

Note, one could also just zip the two lists given that they have the same length:

import csv

dates = ['2020-01-01', '2020-01-02', '2020-01-03']
urls = ['www.abc.com', 'www.cnn.com', 'www.nbc.com']

csv_file_patch = '/path/to/filename.csv'

with open(csv_file_patch, 'w') as fout:
    csv_file = csv.writer(fout, delimiter=';', lineterminator='\n')
    result_array = zip(dates, urls)
    csv_file.writerows(result_array)

How to solve ERR_CONNECTION_REFUSED when trying to connect to localhost running IISExpress - Error 502 (Cannot debug from Visual Studio)?

If you are using "real" IIS, this can occur if the W3SVC (World Wide Web Publishing) service is stopped.

Should seem obvious but if you accidentally stopped the service or have it set to manual this could happen to you.

I know the title says IIS express however google doesn't seem to filter out the express even when using a -Express hint so hopefully this helps someone else who found this page instead of an IIS-specific one.

Scikit-learn train_test_split with indices

You can use pandas dataframes or series as Julien said but if you want to restrict your-self to numpy you can pass an additional array of indices:

from sklearn.model_selection import train_test_split
import numpy as np
n_samples, n_features, n_classes = 10, 2, 2
data = np.random.randn(n_samples, n_features)  # 10 training examples
labels = np.random.randint(n_classes, size=n_samples)  # 10 labels
indices = np.arange(n_samples)
x1, x2, y1, y2, idx1, idx2 = train_test_split(
    data, labels, indices, test_size=0.2)

Scikit-learn: How to obtain True Positive, True Negative, False Positive and False Negative

#False positive cases
train = pd.merge(X_train, y_train,left_index=True, right_index=True)
y_train_pred = pd.DataFrame(y_train_pred)
y_train_pred.rename(columns={0 :'Predicted'}, inplace=True )
train = train.reset_index(drop=True).merge(y_train_pred.reset_index(drop=True),
left_index=True,right_index=True)
train['FP'] = np.where((train['Banknote']=="Forged") & (train['Predicted']=="Genuine"),1,0)
train[train.FP != 0]

What does 'git blame' do?

The git blame command annotates lines with information from the revision which last modified the line, and... with Git 2.22 (Q2 2019), will do so faster, because of a performance fix around "git blame", especially in a linear history (which is the norm we should optimize for).

See commit f892014 (02 Apr 2019) by David Kastrup (fedelibre). (Merged by Junio C Hamano -- gitster -- in commit 4d8c4da, 25 Apr 2019)

blame.c: don't drop origin blobs as eagerly

When a parent blob already has chunks queued up for blaming, dropping the blob at the end of one blame step will cause it to get reloaded right away, doubling the amount of I/O and unpacking when processing a linear history.

Keeping such parent blobs in memory seems like a reasonable optimization that should incur additional memory pressure mostly when processing the merges from old branches.

Impact of Xcode build options "Enable bitcode" Yes/No

From the docs

  • can I use the above method without any negative impact and without compromising a future appstore submission?

Bitcode will allow apple to optimise the app without you having to submit another build. But, you can only enable this feature if all frameworks and apps in the app bundle have this feature enabled. Having it helps, but not having it should not have any negative impact.

  • What does the ENABLE_BITCODE actually do, will it be a non-optional requirement in the future?

For iOS apps, bitcode is the default, but optional. If you provide bitcode, all apps and frameworks in the app bundle need to include bitcode. For watchOS apps, bitcode is required.

  • Are there any performance impacts if I enable / disable it?

The App Store and operating system optimize the installation of iOS and watchOS apps by tailoring app delivery to the capabilities of the user’s particular device, with minimal footprint. This optimization, called app thinning, lets you create apps that use the most device features, occupy minimum disk space, and accommodate future updates that can be applied by Apple. Faster downloads and more space for other apps and content provides a better user experience.

There should not be any performance impacts.

How to change the new TabLayout indicator color and height

Android makes it easy.

public void setTabTextColors(int normalColor, int selectedColor) {
    setTabTextColors(createColorStateList(normalColor, selectedColor));
}

So, we just say

mycooltablayout.setTabTextColors(Color.parseColor("#1464f4"), Color.parseColor("#880088"));

That will give us a blue normal color and purple selected color.

Now we set the height

public void setSelectedTabIndicatorHeight(int height) {
    mTabStrip.setSelectedIndicatorHeight(height);
}

And for height we say

mycooltablayout.setSelectedIndicatorHeight(6);

Guzzlehttp - How get the body of a response from Guzzle 6?

If expecting JSON back, the simplest way to get it:

$data = json_decode($response->getBody()); // returns an object

// OR

$data = json_decode($response->getBody(), true); // returns an array

json_decode() will automatically cast the body to string, so there is no need to call getContents().

Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

Make sure that while using : Button "varName" =findViewById("btID"); you put in the right "btID". I accidentally put in the id of a button from another similar activity and it showed the same error. Hope it helps.

Create a day-of-week column in a Pandas dataframe using Python

Using dt.weekday_name is deprecated since pandas 0.23.0, instead, use dt.day_name():

df = pd.DataFrame({'my_dates':['2015-01-01','2015-01-02','2015-01-03'],'myvals':[1,2,3]})
df['my_dates'] = pd.to_datetime(df['my_dates'])

df['my_dates'].dt.day_name()

0    Thursday
1      Friday
2    Saturday
Name: my_dates, dtype: object

How can I print out just the index of a pandas dataframe?

You can access the index attribute of a df using .index:

In [277]:

df = pd.DataFrame({'a':np.arange(10), 'b':np.random.randn(10)})
df
Out[277]:
   a         b
0  0  0.293422
1  1 -1.631018
2  2  0.065344
3  3 -0.417926
4  4  1.925325
5  5  0.167545
6  6 -0.988941
7  7 -0.277446
8  8  1.426912
9  9 -0.114189
In [278]:

df.index
Out[278]:
Int64Index([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], dtype='int64')

Convert array of indices to 1-hot encoded numpy array

Your array a defines the columns of the nonzero elements in the output array. You need to also define the rows and then use fancy indexing:

>>> a = np.array([1, 0, 3])
>>> b = np.zeros((a.size, a.max()+1))
>>> b[np.arange(a.size),a] = 1
>>> b
array([[ 0.,  1.,  0.,  0.],
       [ 1.,  0.,  0.,  0.],
       [ 0.,  0.,  0.,  1.]])

Manage toolbar's navigation and back button from fragment in android

The easiest solution I found was to simply put that in your fragment :

androidx.appcompat.widget.Toolbar toolbar = getActivity().findViewById(R.id.toolbar);
    toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            NavController navController = Navigation.findNavController(getActivity(), 
R.id.nav_host_fragment);
            navController.navigate(R.id.action_position_to_destination);
        }
    });

Personnaly I wanted to go to another page but of course you can replace the 2 lines in the onClick method by the action you want to perform.

Image resizing in React Native

image auto fix the View

image: {
    flex: 1,
    width: null,
    height: null,
    resizeMode: 'contain'
}

GitHub: invalid username or password

I'm constantly running into this problem. Make sure you set git --config user.name "" and not your real name, which I've done a few times..

How to count down in for loop?

If you google. "Count down for loop python" you get these, which are pretty accurate.

how to loop down in python list (countdown)
Loop backwards using indices in Python?

I recommend doing minor searches before posting. Also "Learn Python The Hard Way" is a good place to start.

Swift Alamofire: How to get the HTTP response status code

you may check the following code for status code handler by alamofire

    let request = URLRequest(url: URL(string:"url string")!)    
    Alamofire.request(request).validate(statusCode: 200..<300).responseJSON { (response) in
        switch response.result {
        case .success(let data as [String:Any]):
            completion(true,data)
        case .failure(let err):
            print(err.localizedDescription)
            completion(false,err)
        default:
            completion(false,nil)
        }
    }

if status code is not validate it will be enter the failure in switch case

Phone Number Validation MVC

Along with the above answers Try this for min and max length:

In Model

[StringLength(13, MinimumLength=10)]
public string MobileNo { get; set; }

In view

 <div class="col-md-8">
           @Html.TextBoxFor(m => m.MobileNo, new { @class = "form-control" , type="phone"})
           @Html.ValidationMessageFor(m => m.MobileNo,"Invalid Number")
           @Html.CheckBoxFor(m => m.IsAgreeTerms, new {@checked="checked",style="display:none" })
  </div>

No resource identifier found for attribute '...' in package 'com.app....'

I solved is by using android:background instead of app:srcCompact.

This is caused by xmlns:app="http://schemas.android.com/apk/res-auto". As people have suggested above, you could use /lib-auto or /lib/your-package but I got suspicious namespace error when I tried using /lib-auto and unexpected namespace prefix error with /lib/my-package .

How to display an activity indicator with text on iOS 8 with Swift?

For Swift 5

Indicator with label inside WKWebview

var strLabel = UILabel()
   let effectView = UIVisualEffectView(effect: UIBlurEffect(style: .dark))
    let loadingTextLabel = UILabel()
   
    @IBOutlet var indicator: UIActivityIndicatorView!
    @IBOutlet var webView: WKWebView!
    
    var refController:UIRefreshControl = UIRefreshControl()
    
    
    override func viewDidLoad() {
        webView = WKWebView(frame: CGRect.zero)
        webView.navigationDelegate = self
        webView.uiDelegate = self as? WKUIDelegate
        
        let preferences = WKPreferences()
        preferences.javaScriptEnabled = true
        let configuration = WKWebViewConfiguration()
        configuration.preferences = preferences
       
        
        webView.allowsBackForwardNavigationGestures = true
        
        webView.load(URLRequest(url: URL(string: "https://www.google.com")!))
        setBackground()
        
    }
    

    
    func setBackground() {
        view.addSubview(webView)
        webView.translatesAutoresizingMaskIntoConstraints = false
        webView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
        webView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
        webView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
        webView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
    }
    
    func showActivityIndicator(show: Bool) {
        if show {
            
            
            strLabel = UILabel(frame: CGRect(x: 55, y: 0, width: 400, height: 66))
            strLabel.text = "Please Wait. Checking Internet Connection..."
            strLabel.font = UIFont(name: "Avenir Light", size: 12)
            
           
            strLabel.textColor = UIColor(white: 0.9, alpha: 0.7)
           
            effectView.frame = CGRect(x: view.frame.midX - strLabel.frame.width/2, y: view.frame.midY - strLabel.frame.height/2 , width: 300, height: 66)
            effectView.layer.cornerRadius = 15
            effectView.layer.masksToBounds = true
            indicator = UIActivityIndicatorView(style: .white)
            indicator.frame = CGRect(x: 0, y: 0, width: 66, height: 66)
            indicator.startAnimating()
            effectView.contentView.addSubview(indicator)
            effectView.contentView.addSubview(strLabel)
            indicator.transform = CGAffineTransform(scaleX: 1.4, y: 1.4);
            effectView.center = webView.center
            view.addSubview(effectView)
            
            
        } else {
            strLabel.removeFromSuperview()
             effectView.removeFromSuperview()
            indicator.removeFromSuperview()
            indicator.stopAnimating()
        }
    }

Here is my screenshort

how to rename an index in a cluster?

If you can't REINDEX a workaround is to use aliases. From the official documentation:

APIs in elasticsearch accept an index name when working against a specific index, and several indices when applicable. The index aliases API allow to alias an index with a name, with all APIs automatically converting the alias name to the actual index name. An alias can also be mapped to more than one index, and when specifying it, the alias will automatically expand to the aliases indices. An alias can also be associated with a filter that will automatically be applied when searching, and routing values. An alias cannot have the same name as an index.

Be aware that this solution does not work if you're using More Like This feature. https://github.com/elastic/elasticsearch/issues/16560

JsonParseException: Unrecognized token 'http': was expecting ('true', 'false' or 'null')

We have the following string which is a valid JSON ...

Clearly the JSON parser disagrees!

However, the exception says that the error is at "line 1: column 9", and there is no "http" token near the beginning of the JSON. So I suspect that the parser is trying to parse something different than this string when the error occurs.

You need to find what JSON is actually being parsed. Run the application within a debugger, set a breakpoint on the relevant constructor for JsonParseException ... then find out what is in the ByteArrayInputStream that it is attempting to parse.

Finding rows containing a value (or values) in any column

Here's a dplyr option:

library(dplyr)

# across all columns:
df %>% filter_all(any_vars(. %in% c('M017', 'M018')))

# or in only select columns:
df %>% filter_at(vars(col1, col2), any_vars(. %in% c('M017', 'M018')))                                                                                                     

What is difference between @RequestBody and @RequestParam?

It is very simple just look at their names @RequestParam it consist of two parts one is "Request" which means it is going to deal with request and other part is "Param" which itself makes sense it is going to map only the parameters of requests to java objects. Same is the case with @RequestBody it is going to deal with the data that has been arrived with request like if client has send json object or xml with request at that time @requestbody must be used.

IndexError: too many indices for array

I think the problem is given in the error message, although it is not very easy to spot:

IndexError: too many indices for array
xs  = data[:, col["l1"     ]]

'Too many indices' means you've given too many index values. You've given 2 values as you're expecting data to be a 2D array. Numpy is complaining because data is not 2D (it's either 1D or None).

This is a bit of a guess - I wonder if one of the filenames you pass to loadfile() points to an empty file, or a badly formatted one? If so, you might get an array returned that is either 1D, or even empty (np.array(None) does not throw an Error, so you would never know...). If you want to guard against this failure, you can insert some error checking into your loadfile function.

I highly recommend in your for loop inserting:

print(data)

This will work in Python 2.x or 3.x and might reveal the source of the issue. You might well find it is only one value of your outputs_l1 list (i.e. one file) that is giving the issue.

Why does git status show branch is up-to-date when changes exist upstream?

While these are all viable answers, I decided to give my way of checking if local repo is in line with the remote, whithout fetching or pulling. In order to see where my branches are I use simply:

git remote show origin

What it does is return all the current tracked branches and most importantly - the info whether they are up to date, ahead or behind the remote origin ones. After the above command, this is an example of what is returned:

  * remote origin
  Fetch URL: https://github.com/xxxx/xxxx.git
  Push  URL: https://github.com/xxxx/xxxx.git
  HEAD branch: master
  Remote branches:
    master      tracked
    no-payments tracked
  Local branches configured for 'git pull':
    master      merges with remote master
    no-payments merges with remote no-payments
  Local refs configured for 'git push':
    master      pushes to master      (local out of date)
    no-payments pushes to no-payments (local out of date)

Hope this helps someone.

Pandas concat: ValueError: Shape of passed values is blah, indices imply blah2

My problem were different indices, the following code solved my problem.

df1.reset_index(drop=True, inplace=True)
df2.reset_index(drop=True, inplace=True)
df = pd.concat([df1, df2], axis=1)

How do I create a master branch in a bare Git repository?

By default there will be no branches listed and pops up only after some file is placed. You don't have to worry much about it. Just run all your commands like creating folder structures, adding/deleting files, commiting files, pushing it to server or creating branches. It works seamlessly without any issue.

https://git-scm.com/docs

Programmatically Add CenterX/CenterY Constraints

Programmatically you can do it by adding the following constraints.

NSLayoutConstraint *constraintHorizontal = [NSLayoutConstraint constraintWithItem:self  
                                                                      attribute:NSLayoutAttributeCenterX 
                                                                      relatedBy:NSLayoutRelationEqual 
                                                                         toItem:self.superview 
                                                                      attribute:attribute 
                                                                     multiplier:1.0f 
                                                                       constant:0.0f];

NSLayoutConstraint *constraintVertical = [NSLayoutConstraint constraintWithItem:self
                                                                        attribute:NSLayoutAttributeCenterY 
                                                                        relatedBy:NSLayoutRelationEqual
                                                                           toItem:self.superview 
                                                                        attribute:attribute 
                                                                       multiplier:1.0f
                                                                         constant:0.0f];

How to use SearchView in Toolbar Android

Implementing the SearchView without the use of the menu.xml file and open through button

In your Activity we need to use the method of the onCreateOptionsMenumethod in which we will programmatically inflate the SearchView

private MenuItem searchMenu;
private String mSearchString="";

@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);

        SearchManager searchManager = (SearchManager) StoreActivity.this.getSystemService(Context.SEARCH_SERVICE);


        SearchView mSearchView = new SearchView(getSupportActionBar().getThemedContext());
        mSearchView.setQueryHint(getString(R.string.prompt_search)); /// YOUR HINT MESSAGE
        mSearchView.setMaxWidth(Integer.MAX_VALUE);

        searchMenu = menu.add("searchMenu").setVisible(false).setActionView(mSearchView);
        searchMenu.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM | MenuItem.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW);


        assert searchManager != null;
        mSearchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
        mSearchView.setIconifiedByDefault(false);

        SearchView.OnQueryTextListener queryTextListener = new SearchView.OnQueryTextListener() {
            public boolean onQueryTextChange(String newText) {
                mSearchString = newText;

                return true;
            }

            public boolean onQueryTextSubmit(String query) {
                mSearchString = query;

                searchMenu.collapseActionView();


                return true;
            }
        };

        mSearchView.setOnQueryTextListener(queryTextListener);


        return true;
    }

And in your Activity class, you can open the SearchView on any button click on toolbar like below

YOUR_BUTTON.setOnClickListener(view -> {

            searchMenu.expandActionView();

        });

How to check Elasticsearch cluster health?

To check on elasticsearch cluster health you need to use

curl localhost:9200/_cat/health

More on the cat APIs here.

I usually use elasticsearch-head plugin to visualize that.

You can find it's github project here.

It's easy to install sudo $ES_HOME/bin/plugin -i mobz/elasticsearch-head and then you can open localhost:9200/_plugin/head/ in your web brower.

You should have something that looks like this :

enter image description here

Python: find position of element in array

Have you thought about using Python list's .index(value) method? It return the index in the list of where the first instance of the value passed in is found.

NullPointerException: Attempt to invoke virtual method 'int java.util.ArrayList.size()' on a null object reference

This issue is due to ArrayList variable not being instantiated. Need to declare "recordings" variable like following, that should solve the issue;

ArrayList<String> recordings = new ArrayList<String>();

this calls default constructor and assigns empty string to the recordings variable so that it is not null anymore.

ORA-01653: unable to extend table by in tablespace ORA-06512

To resolve this error:

ORA-01653 unable to extend table by 1024 in tablespace your-tablespace-name

Just run this PL/SQL command for extended tablespace size automatically on-demand:

alter database datafile '<your-tablespace-name>.dbf' autoextend on maxsize unlimited;

I get this error in import big dump file, just run this command without stopping import routine or restarting the database.

Note: each data file has a limit of 32GB of size if you need more than 32GB you should add a new data file to your existing tablespace.

More info: alter_autoextend_on

Solve Cross Origin Resource Sharing with Flask

Well, I faced the same issue. For new users who may land at this page. Just follow their official documentation.

Install flask-cors

pip install -U flask-cors

then after app initialization, initialize flask-cors with default arguments:

from flask import Flask
from flask_cors import CORS

app = Flask(__name__)
CORS(app)

@app.route("/")
def helloWorld():
   return "Hello, cross-origin-world!"

How to delete the last row of data of a pandas dataframe

DF[:-n]

where n is the last number of rows to drop.

To drop the last row :

DF = DF[:-1]

How to change color of the back arrow in the new material theme?

Use below method:

private Drawable getColoredArrow() {
    Drawable arrowDrawable = getResources().getDrawable(R.drawable.abc_ic_ab_back_mtrl_am_alpha);
    Drawable wrapped = DrawableCompat.wrap(arrowDrawable);

    if (arrowDrawable != null && wrapped != null) {
        // This should avoid tinting all the arrows
        arrowDrawable.mutate();
        DrawableCompat.setTint(wrapped, Color.GRAY);
    }

    return wrapped;
}

Now you can set the drawable with:

getSupportActionBar().setHomeAsUpIndicator(getColoredArrow());

Converting dictionary to JSON

json.dumps() returns the JSON string representation of the python dict. See the docs

You can't do r['rating'] because r is a string, not a dict anymore

Perhaps you meant something like

r = {'is_claimed': 'True', 'rating': 3.5}
json = json.dumps(r) # note i gave it a different name
file.write(str(r['rating']))

Multiple scenarios @RequestMapping produces JSON/XML together with Accept or ResponseEntity

I've preferred using the params filter for parameter-centric content-type.. I believe that should work in conjunction with the produces attribute.

@GetMapping(value="/person/{id}/", 
            params="format=json",
            produces=MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<Person> getPerson(@PathVariable Integer id){
    Person person = personMapRepository.findPerson(id);
    return ResponseEntity.ok(person);
} 
@GetMapping(value="/person/{id}/", 
            params="format=xml",
            produces=MediaType.APPLICATION_XML_VALUE)
public ResponseEntity<Person> getPersonXML(@PathVariable Integer id){
    return GetPerson(id); // delegate
}

Removing NA in dplyr pipe

I don't think desc takes an na.rm argument... I'm actually surprised it doesn't throw an error when you give it one. If you just want to remove NAs, use na.omit (base) or tidyr::drop_na:

outcome.df %>%
  na.omit() %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

library(tidyr)
outcome.df %>%
  drop_na() %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

If you only want to remove NAs from the HeartAttackDeath column, filter with is.na, or use tidyr::drop_na:

outcome.df %>%
  filter(!is.na(HeartAttackDeath)) %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

outcome.df %>%
  drop_na(HeartAttackDeath) %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

As pointed out at the dupe, complete.cases can also be used, but it's a bit trickier to put in a chain because it takes a data frame as an argument but returns an index vector. So you could use it like this:

outcome.df %>%
  filter(complete.cases(.)) %>%
  group_by(Hospital, State) %>%
  arrange(desc(HeartAttackDeath)) %>%
  head()

How do I get the name of the rows from the index of a data frame?

If you want to pull out only the index values for certain integer-based row-indices, you can do something like the following using the iloc method:

In [28]: temp
Out[28]:
       index                 time  complete
row_0      2  2014-10-22 01:00:00         0
row_1      3  2014-10-23 14:00:00         0
row_2      4  2014-10-26 08:00:00         0
row_3      5  2014-10-26 10:00:00         0
row_4      6  2014-10-26 11:00:00         0

In [29]: temp.iloc[[0,1,4]].index
Out[29]: Index([u'row_0', u'row_1', u'row_4'], dtype='object')

In [30]: temp.iloc[[0,1,4]].index.tolist()
Out[30]: ['row_0', 'row_1', 'row_4']

Cannot catch toolbar home button click event

In my case I had to put the icon using:

toolbar.setNavigationIcon(R.drawable.ic_my_home);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);

And then listen to click events with default onOptionsItemSelected and android.R.id.home id

how to move elasticsearch data from one server to another

You can use snapshot/restore feature available in Elasticsearch for this. Once you have setup a Filesystem based snapshot store, you can move it around between clusters and restore on a different cluster

matplotlib get ylim values

Leveraging from the good answers above and assuming you were only using plt as in

import matplotlib.pyplot as plt

then you can get all four plot limits using plt.axis() as in the following example.

import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5, 6, 7, 8]  # fake data
y = [1, 2, 3, 4, 3, 2, 5, 6]

plt.plot(x, y, 'k')

xmin, xmax, ymin, ymax = plt.axis()

s = 'xmin = ' + str(round(xmin, 2)) + ', ' + \
    'xmax = ' + str(xmax) + '\n' + \
    'ymin = ' + str(ymin) + ', ' + \
    'ymax = ' + str(ymax) + ' '

plt.annotate(s, (1, 5))

plt.show()

The above code should produce the following output plot. enter image description here

Using tr to replace newline with space

Best guess is you are on windows and your line ending settings are set for windows. See this topic: How to change line-ending settings

or use:

tr '\r\n' ' '

ORA-01652: unable to extend temp segment by 128 in tablespace SYSTEM: How to extend?

Each tablespace has one or more datafiles that it uses to store data.

The max size of a datafile depends on the block size of the database. I believe that, by default, that leaves with you with a max of 32gb per datafile.

To find out if the actual limit is 32gb, run the following:

select value from v$parameter where name = 'db_block_size';

Compare the result you get with the first column below, and that will indicate what your max datafile size is.

I have Oracle Personal Edition 11g r2 and in a default install it had an 8,192 block size (32gb per data file).

Block Sz   Max Datafile Sz (Gb)   Max DB Sz (Tb)

--------   --------------------   --------------

   2,048                  8,192          524,264

   4,096                 16,384        1,048,528

   8,192                 32,768        2,097,056

  16,384                 65,536        4,194,112

  32,768                131,072        8,388,224

You can run this query to find what datafiles you have, what tablespaces they are associated with, and what you've currrently set the max file size to (which cannot exceed the aforementioned 32gb):

select bytes/1024/1024 as mb_size,
       maxbytes/1024/1024 as maxsize_set,
       x.*
from   dba_data_files x

MAXSIZE_SET is the maximum size you've set the datafile to. Also relevant is whether you've set the AUTOEXTEND option to ON (its name does what it implies).

If your datafile has a low max size or autoextend is not on you could simply run:

alter database datafile 'path_to_your_file\that_file.DBF' autoextend on maxsize unlimited;

However if its size is at/near 32gb an autoextend is on, then yes, you do need another datafile for the tablespace:

alter tablespace system add datafile 'path_to_your_datafiles_folder\name_of_df_you_want.dbf' size 10m autoextend on maxsize unlimited;

Completely Remove MySQL Ubuntu 14.04 LTS

I experienced a similar issue on Ubuntu 14.04 LTS after a MySQL update.

I started getting error: "Fatal error: Can't open and lock privilege tables: Incorrect file format 'user'" in /var/log/mysql/error.log

MySQL could not start.

I resolved it by removing the following directory: /var/lib/mysql/mysql

sudo rm -rf /var/lib/mysql/mysql

This leaves your other DB related files in place, only removing the mysql related files.

After running these:

sudo apt-get remove --purge mysql-server mysql-client mysql-common
sudo apt-get autoremove
sudo apt-get autoclean

Then reinstalling mysql:

sudo apt-get install mysql-server

It worked perfectly.

Avoid dropdown menu close on click inside

I modified @Vartan's answer to make it work with Bootstrap 4.3. His solution doesn't work anymore with the latest version as target property always returns dropdown's root div no matter where the click was placed.

Here is the code:

$('.dropdown-keep-open').on('hide.bs.dropdown', function (e) {
  if (!e.clickEvent) {
    // There is no `clickEvent` property in the `e` object when the `button` (or any other trigger) is clicked. 
    // What we usually want to happen in such situations is to hide the dropdown so we let it hide. 
    return true;
  }

  var target = $(e.clickEvent.target);

  return !(target.hasClass('dropdown-keep-open') || target.parents('.dropdown-keep-open').length);
});
<div class="dropdown dropdown-keep-open">
  <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Dropdown button
  </button>
  <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
    <a class="dropdown-item" href="#">Action</a>
    <a class="dropdown-item" href="#">Another action</a>
    <a class="dropdown-item" href="#">Something else here</a>
  </div>
</div>

How to draw vertical lines on a given plot in matplotlib

The standard way to add vertical lines that will cover your entire plot window without you having to specify their actual height is plt.axvline

import matplotlib.pyplot as plt

plt.axvline(x=0.22058956)
plt.axvline(x=0.33088437)
plt.axvline(x=2.20589566)

OR

xcoords = [0.22058956, 0.33088437, 2.20589566]
for xc in xcoords:
    plt.axvline(x=xc)

You can use many of the keywords available for other plot commands (e.g. color, linestyle, linewidth ...). You can pass in keyword arguments ymin and ymax if you like in axes corrdinates (e.g. ymin=0.25, ymax=0.75 will cover the middle half of the plot). There are corresponding functions for horizontal lines (axhline) and rectangles (axvspan).

What is an AssertionError? In which case should I throw it from my own code?

The meaning of an AssertionError is that something happened that the developer thought was impossible to happen.

So if an AssertionError is ever thrown, it is a clear sign of a programming error.

The listener supports no services

You need to add your ORACLE_HOME definition in your listener.ora file. Right now its not registered with any ORACLE_HOME.

Sample listener.ora

abc =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = abc.kma.com)(PORT = 1521))
    )
  )

SID_LIST_abc =
  (SID_LIST =
    (SID_DESC =
      (ORACLE_HOME= /abc/DbTier/11.2.0)
      (SID_NAME = abc)
    )
  )

TypeError: Cannot read property 'then' of undefined

TypeError: Cannot read property 'then' of undefined when calling a Django service using AngularJS.

If you are calling a Python service, the code will look like below:

this.updateTalentSupplier=function(supplierObj){
  var promise = $http({
    method: 'POST',
      url: bbConfig.BWS+'updateTalentSupplier/',
      data:supplierObj,
      withCredentials: false,
      contentType:'application/json',
      dataType:'json'
    });
    return promise; //Promise is returned 
}

We are using MongoDB as the database(I know it doesn't matter. But if someone is searching with MongoDB + Python (Django) + AngularJS the result should come.

Python and JSON - TypeError list indices must be integers not str

You can simplify your code down to

url = "http://worldcup.kimonolabs.com/api/players?apikey=xxx"
json_obj = urllib2.urlopen(url).read
player_json_list = json.loads(json_obj)
for player in readable_json_list:
    print player['firstName']

You were trying to access a list element using dictionary syntax. the equivalent of

foo = [1, 2, 3, 4]
foo["1"]

It can be confusing when you have lists of dictionaries and keeping the nesting in order.

What exactly does the Access-Control-Allow-Credentials header do?

By default, CORS does not include cookies on cross-origin requests. This is different from other cross-origin techniques such as JSON-P. JSON-P always includes cookies with the request, and this behavior can lead to a class of vulnerabilities called cross-site request forgery, or CSRF.

In order to reduce the chance of CSRF vulnerabilities in CORS, CORS requires both the server and the client to acknowledge that it is ok to include cookies on requests. Doing this makes cookies an active decision, rather than something that happens passively without any control.

The client code must set the withCredentials property on the XMLHttpRequest to true in order to give permission.

However, this header alone is not enough. The server must respond with the Access-Control-Allow-Credentials header. Responding with this header to true means that the server allows cookies (or other user credentials) to be included on cross-origin requests.

You also need to make sure your browser isn't blocking third-party cookies if you want cross-origin credentialed requests to work.

Note that regardless of whether you are making same-origin or cross-origin requests, you need to protect your site from CSRF (especially if your request includes cookies).

How to use pull to refresh in Swift?

For the pull to refresh i am using

DGElasticPullToRefresh

https://github.com/gontovnik/DGElasticPullToRefresh

Installation

pod 'DGElasticPullToRefresh'

import DGElasticPullToRefresh

and put this function into your swift file and call this funtion from your

override func viewWillAppear(_ animated: Bool)

     func Refresher() {
      let loadingView = DGElasticPullToRefreshLoadingViewCircle()
      loadingView.tintColor = UIColor(red: 255.0/255.0, green: 255.0/255.0, blue: 255.0/255.0, alpha: 1.0)
      self.table.dg_addPullToRefreshWithActionHandler({ [weak self] () -> Void in

          //Completion block you can perfrom your code here.

           print("Stack Overflow")

           self?.table.dg_stopLoading()
           }, loadingView: loadingView)
      self.table.dg_setPullToRefreshFillColor(UIColor(red: 255.0/255.0, green: 57.0/255.0, blue: 66.0/255.0, alpha: 1))
      self.table.dg_setPullToRefreshBackgroundColor(self.table.backgroundColor!)
 }

And dont forget to remove reference while view will get dissapear

to remove pull to refresh put this code in to your

override func viewDidDisappear(_ animated: Bool)

override func viewDidDisappear(_ animated: Bool) {
      table.dg_removePullToRefresh()

 }

And it will looks like

enter image description here

Happy coding :)

SSL Error: unable to get local issuer certificate

If you are a linux user Update node to a later version by running

sudo apt update

 sudo apt install build-essential checkinstall libssl-dev

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.35.1/install.sh | bash

nvm --version

nvm ls

nvm ls-remote

nvm install [version.number]

this should solve your problem

Does Java SE 8 have Pairs or Tuples?

Yes.

Map.Entry can be used as a Pair.

Unfortunately it does not help with Java 8 streams as the problem is that even though lambdas can take multiple arguments, the Java language only allows for returning a single value (object or primitive type). This implies that whenever you have a stream you end up with being passed a single object from the previous operation. This is a lack in the Java language, because if multiple return values was supported AND streams supported them we could have much nicer non-trivial tasks done by streams.

Until then, there is only little use.

EDIT 2018-02-12: While working on a project I wrote a helper class which helps handling the special case of having an identifier earlier in the stream you need at a later time but the stream part in between does not know about it. Until I get around to release it on its own it is available at IdValue.java with a unit test at IdValueTest.java

Shall we always use [unowned self] inside closure in Swift

There are some great answers here. But recent changes to how Swift implements weak references should change everyone's weak self vs. unowned self usage decisions. Previously, if you needed the best performance using unowned self was superior to weak self, as long as you could be certain that self would never be nil, because accessing unowned self is much faster than accessing weak self.

But Mike Ash has documented how Swift has updated the implementation of weak vars to use side-tables and how this substantially improves weak self performance.

https://mikeash.com/pyblog/friday-qa-2017-09-22-swift-4-weak-references.html

Now that there isn't a significant performance penalty to weak self, I believe we should default to using it going forward. The benefit of weak self is that it's an optional, which makes it far easier to write more correct code, it's basically the reason Swift is such a great language. You may think you know which situations are safe for the use of unowned self, but my experience reviewing lots of other developers code is, most don't. I've fixed lots of crashes where unowned self was deallocated, usually in situations where a background thread completes after a controller is deallocated.

Bugs and crashes are the most time-consuming, painful and expensive parts of programming. Do your best to write correct code and avoid them. I recommend making it a rule to never force unwrap optionals and never use unowned self instead of weak self. You won't lose anything missing the times force unwrapping and unowned self actually are safe. But you'll gain a lot from eliminating hard to find and debug crashes and bugs.

Argparse: Required arguments listed under "optional arguments"?

Building off of @Karl Rosaen

parser = argparse.ArgumentParser()
optional = parser._action_groups.pop() # Edited this line
required = parser.add_argument_group('required arguments')
# remove this line: optional = parser...
required.add_argument('--required_arg', required=True)
optional.add_argument('--optional_arg')
parser._action_groups.append(optional) # added this line
return parser.parse_args()

and this outputs:

usage: main.py [-h] [--required_arg REQUIRED_ARG]
           [--optional_arg OPTIONAL_ARG]

required arguments:
  --required_arg REQUIRED_ARG

optional arguments:
  -h, --help                    show this help message and exit
  --optional_arg OPTIONAL_ARG

What is an optional value in Swift?

Well...

? (Optional) indicates your variable may contain a nil value while ! (unwrapper) indicates your variable must have a memory (or value) when it is used (tried to get a value from it) at runtime.

The main difference is that optional chaining fails gracefully when the optional is nil, whereas forced unwrapping triggers a runtime error when the optional is nil.

To reflect the fact that optional chaining can be called on a nil value, the result of an optional chaining call is always an optional value, even if the property, method, or subscript you are querying returns a nonoptional value. You can use this optional return value to check whether the optional chaining call was successful (the returned optional contains a value), or did not succeed due to a nil value in the chain (the returned optional value is nil).

Specifically, the result of an optional chaining call is of the same type as the expected return value, but wrapped in an optional. A property that normally returns an Int will return an Int? when accessed through optional chaining.

var defaultNil : Int?  // declared variable with default nil value
println(defaultNil) >> nil  

var canBeNil : Int? = 4
println(canBeNil) >> optional(4)

canBeNil = nil
println(canBeNil) >> nil

println(canBeNil!) >> // Here nil optional variable is being unwrapped using ! mark (symbol), that will show runtime error. Because a nil optional is being tried to get value using unwrapper

var canNotBeNil : Int! = 4
print(canNotBeNil) >> 4

var cantBeNil : Int = 4
cantBeNil = nil // can't do this as it's not optional and show a compile time error

Here is basic tutorial in detail, by Apple Developer Committee: Optional Chaining

Project with path ':mypath' could not be found in root project 'myproject'

Remove all the texts in android/settings.gradle and paste the below code

rootProject.name = '****Your Project Name****'
apply from: file("../node_modules/@react-native-community/cli-platform-android/native_modules.gradle"); applyNativeModulesSettingsGradle(settings)
include ':app'

This issue will usually happen when you migrate from react-native < 0.60 to react-native >0.60. If you create a new project in react-native >0.60 you will see the same settings as above mentioned

NullPointerException in eclipse in Eclipse itself at PartServiceImpl.internalFixContext

I faced the same error, but only with files cloned from git that were assigned to a proprietary plugin. I realized that even after cloning the files from git, I needed to create a new project or import a project in eclipse and this resolved the error.

Selecting specific rows and columns from NumPy array

Fancy indexing requires you to provide all indices for each dimension. You are providing 3 indices for the first one, and only 2 for the second one, hence the error. You want to do something like this:

>>> a[[[0, 0], [1, 1], [3, 3]], [[0,2], [0,2], [0, 2]]]
array([[ 0,  2],
       [ 4,  6],
       [12, 14]])

That is of course a pain to write, so you can let broadcasting help you:

>>> a[[[0], [1], [3]], [0, 2]]
array([[ 0,  2],
       [ 4,  6],
       [12, 14]])

This is much simpler to do if you index with arrays, not lists:

>>> row_idx = np.array([0, 1, 3])
>>> col_idx = np.array([0, 2])
>>> a[row_idx[:, None], col_idx]
array([[ 0,  2],
       [ 4,  6],
       [12, 14]])

warning: control reaches end of non-void function [-Wreturn-type]

You just need to return from the main function at some point. The error message says that the function is defined to return a value but you are not returning anything.

  /* .... */
  if (Date1 == Date2)  
     fprintf (stderr , "Indicating that the first date is equal to second date.\n"); 

  return 0;
}

Conditionally formatting if multiple cells are blank (no numerics throughout spreadsheet )

enter image description here

How about just > Format only cells that contain - in the drop down box select Blanks

How can I plot separate Pandas DataFrames as subplots?

Here is a working pandas subplot example, where modes is the column names of the dataframe.

    dpi=200
    figure_size=(20, 10)
    fig, ax = plt.subplots(len(modes), 1, sharex="all", sharey="all", dpi=dpi)
    for i in range(len(modes)):
        ax[i] = pivot_df.loc[:, modes[i]].plot.bar(figsize=(figure_size[0], figure_size[1]*len(modes)),
                                                   ax=ax[i], title=modes[i], color=my_colors[i])
        ax[i].legend()
    fig.suptitle(name)

Pandas subplot bar example

Create hive table using "as select" or "like" and also specify delimiter

Both the answers provided above work fine.

  1. CREATE TABLE person AS select * from employee;
  2. CREATE TABLE person LIKE employee;

Pandas: change data type of Series to String

You can convert all elements of id to str using apply

df.id.apply(str)

0        123
1        512
2      zhub1
3    12354.3
4        129
5        753
6        295
7        610

Edit by OP:

I think the issue was related to the Python version (2.7.), this worked:

df['id'].astype(basestring)
0        123
1        512
2      zhub1
3    12354.3
4        129
5        753
6        295
7        610
Name: id, dtype: object

Transaction count after EXECUTE indicates a mismatching number of BEGIN and COMMIT statements. Previous count = 1, current count = 0

In my case, the error was being caused by a RETURN inside the BEGIN TRANSACTION. So I had something like this:

Begin Transaction
 If (@something = 'foo')
 Begin
     --- do some stuff
     Return
 End
commit

and it needs to be:

Begin Transaction
 If (@something = 'foo')
 Begin
     --- do some stuff
     Rollback Transaction ----- THIS WAS MISSING
     Return
 End
commit

Python 'list indices must be integers, not tuple"

The problem is that [...] in python has two distinct meanings

  1. expr [ index ] means accessing an element of a list
  2. [ expr1, expr2, expr3 ] means building a list of three elements from three expressions

In your code you forgot the comma between the expressions for the items in the outer list:

[ [a, b, c] [d, e, f] [g, h, i] ]

therefore Python interpreted the start of second element as an index to be applied to the first and this is what the error message is saying.

The correct syntax for what you're looking for is

[ [a, b, c], [d, e, f], [g, h, i] ]

Summarizing multiple columns with dplyr?

We can summarize by using summarize_at, summarize_all and summarize_if on dplyr 0.7.4. We can set the multiple columns and functions by using vars and funs argument as below code. The left-hand side of funs formula is assigned to suffix of summarized vars. In the dplyr 0.7.4, summarise_each(and mutate_each) is already deprecated, so we cannot use these functions.

options(scipen = 100, dplyr.width = Inf, dplyr.print_max = Inf)

library(dplyr)
packageVersion("dplyr")
# [1] ‘0.7.4’

set.seed(123)
df <- data_frame(
  a = sample(1:5, 10, replace=T), 
  b = sample(1:5, 10, replace=T), 
  c = sample(1:5, 10, replace=T), 
  d = sample(1:5, 10, replace=T), 
  grp = as.character(sample(1:3, 10, replace=T)) # For convenience, specify character type
)

df %>% group_by(grp) %>% 
  summarise_each(.vars = letters[1:4],
                 .funs = c(mean="mean"))
# `summarise_each()` is deprecated.
# Use `summarise_all()`, `summarise_at()` or `summarise_if()` instead.
# To map `funs` over a selection of variables, use `summarise_at()`
# Error: Strings must match column names. Unknown columns: mean

You should change to the following code. The following codes all have the same result.

# summarise_at
df %>% group_by(grp) %>% 
  summarise_at(.vars = letters[1:4],
               .funs = c(mean="mean"))

df %>% group_by(grp) %>% 
  summarise_at(.vars = names(.)[1:4],
               .funs = c(mean="mean"))

df %>% group_by(grp) %>% 
  summarise_at(.vars = vars(a,b,c,d),
               .funs = c(mean="mean"))

# summarise_all
df %>% group_by(grp) %>% 
  summarise_all(.funs = c(mean="mean"))

# summarise_if
df %>% group_by(grp) %>% 
  summarise_if(.predicate = function(x) is.numeric(x),
               .funs = funs(mean="mean"))
# A tibble: 3 x 5
# grp a_mean b_mean c_mean d_mean
# <chr>  <dbl>  <dbl>  <dbl>  <dbl>
# 1     1   2.80   3.00    3.6   3.00
# 2     2   4.25   2.75    4.0   3.75
# 3     3   3.00   5.00    1.0   2.00

You can also have multiple functions.

df %>% group_by(grp) %>% 
  summarise_at(.vars = letters[1:2],
               .funs = c(Mean="mean", Sd="sd"))
# A tibble: 3 x 5
# grp a_Mean b_Mean      a_Sd     b_Sd
# <chr>  <dbl>  <dbl>     <dbl>    <dbl>
# 1     1   2.80   3.00 1.4832397 1.870829
# 2     2   4.25   2.75 0.9574271 1.258306
# 3     3   3.00   5.00        NA       NA

Python: converting a list of dictionaries to json

To convert it to a single dictionary with some decided keys value, you can use the code below.

data = ListOfDict.copy()
PrecedingText = "Obs_"
ListOfDictAsDict = {}
for i in range(len(data)):
    ListOfDictAsDict[PrecedingText + str(i)] = data[i]

What does numpy.random.seed(0) do?

numpy.random.seed(0)
numpy.random.randint(10, size=5)

This produces the following output: array([5, 0, 3, 3, 7]) Again,if we run the same code we will get the same result.

Now if we change the seed value 0 to 1 or others:

numpy.random.seed(1)
numpy.random.randint(10, size=5)

This produces the following output: array([5 8 9 5 0]) but now the output not the same like above.

How to uninstall with msiexec using product id guid without .msi file present

"Reference-Style" Answer: This is an alternative answer to the one below with several different options shown. Uninstalling an MSI file from the command line without using msiexec.


The command you specify is correct: msiexec /x {A4BFF20C-A21E-4720-88E5-79D5A5AEB2E8}

If you get "This action is only valid for products that are currently installed" you have used an unrecognized product or package code, and you must find the right one. Often this can be caused by using an erroneous package code instead of a product code to uninstall - a package code changes with every rebuild of an MSI file, and is the only guid you see when you view an msi file's property page. It should work for uninstall, provided you use the right one. No room for error. If you want to find the product code instead, you need to open the MSI. The product code is found in the Property table.


UPDATE, Jan 2018:

With all the registry redirects going on, I am not sure the below registry-based approach is a viable option anymore. I haven't checked properly because I now rely on the following approach using PowerShell: How can I find the product GUID of an installed MSI setup?

Also check this reference-style answer describing different ways to uninstall an MSI package and ways to determine what product version you have installed: Uninstalling an MSI file from the command line without using msiexec


Legacy, registry option:

You can also find the product code by perusing the registry from this base key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall . Press F3 and search for your product name. (If it's a 32-bit installer on a 64-bit machine, it might be under HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall instead).

Legacy, PowerShell option: (largely similar to the new, linked answer above)

Finally, you can find the product code by using PowerShell:

get-wmiobject Win32_Product | Format-Table IdentifyingNumber, Name

enter image description here

Similar post: WiX - Doing a major upgrade on a multi instance install (screenshot of how to find the product code in the MSI).

Getting indices of True values in a boolean list

TL; DR: use np.where as it is the fastest option. Your options are np.where, itertools.compress, and list comprehension.

See the detailed comparison below, where it can be seen np.where outperforms both itertools.compress and also list comprehension.

>>> from itertools import compress
>>> import numpy as np
>>> t = [False, False, False, False, True, True, False, True, False, False, False, False, False, False, False, False]`
>>> t = 1000*t
  • Method 1: Using list comprehension
>>> %timeit [i for i, x in enumerate(t) if x]
457 µs ± 1.5 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)
  • Method 2: Using itertools.compress
>>> %timeit list(compress(range(len(t)), t))
210 µs ± 704 ns per loop (mean ± std. dev. of 7 runs, 1000 loops each)
  • Method 3 (the fastest method): Using numpy.where
>>> %timeit np.where(t)
179 µs ± 593 ns per loop (mean ± std. dev. of 7 runs, 10000 loops each)

How to make Bootstrap carousel slider use mobile left/right swipe

See this solution: Bootstrap TouchCarousel. A drop-in perfection for Twitter Bootstrap's Carousel (v3) to enable gestures on touch devices. http://ixisio.github.io/bootstrap-touch-carousel/

Using grep to help subset a data frame in R

You may also use the stringr package

library(dplyr)
library(stringr)
My.Data %>% filter(str_detect(x, '^G45'))

You may not use '^' (starts with) in this case, to obtain the results you need

How to refresh or show immediately in datagridview after inserting?

In the form designer add a new timer using the toolbox. In properties set "Enabled" equal to "True".

enter image description here

The set the DataGridView to equal your new data in the timer

enter image description here

Apache: "AuthType not set!" 500 Error

The problem here can be formulated another way: how do I make a config that works both in apache 2.2 and 2.4?

Require all granted is only in 2.4, but Allow all ... stops working in 2.4, and we want to be able to rollout a config that works in both.

The only solution I found, which I am not sure is the proper one, is to use:

# backwards compatibility with apache 2.2
Order allow,deny
Allow from all

# forward compatibility with apache 2.4
Require all granted
Satisfy Any

This should resolve your problem, or at least did for me. Now the problem will probably be much harder to solve if you have more complex access rules...

See also this fairly similar question. The Debian wiki also has useful instructions for supporting both 2.2 and 2.4.

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException Error

NullPointerExceptions are among the easier exceptions to diagnose, frequently. Whenever you get an exception in Java and you see the stack trace ( that's what your second quote-block is called, by the way ), you read from top to bottom. Often, you will see exceptions that start in Java library code or in native implementations methods, for diagnosis you can just skip past those until you see a code file that you wrote.

Then you like at the line indicated and look at each of the objects ( instantiated classes ) on that line -- one of them was not created and you tried to use it. You can start by looking up in your code to see if you called the constructor on that object. If you didn't, then that's your problem, you need to instantiate that object by calling new Classname( arguments ). Another frequent cause of NullPointerExceptions is accidentally declaring an object with local scope when there is an instance variable with the same name.

In your case, the exception occurred in your constructor for Workshop on line 75. <init> means the constructor for a class. If you look on that line in your code, you'll see the line

denimjeansButton.addItemListener(this);

There are fairly clearly two objects on this line: denimjeansButton and this. this is synonymous with the class instance you are currently in and you're in the constructor, so it can't be this. denimjeansButton is your culprit. You never instantiated that object. Either remove the reference to the instance variable denimjeansButton or instantiate it.

Python json.loads shows ValueError: Extra data

You can just read from a file, jsonifying each line as you go:

tweets = []
for line in open('tweets.json', 'r'):
    tweets.append(json.loads(line))

This avoids storing intermediate python objects. As long as your write one full tweet per append() call, this should work.

How to fix: "HAX is not working and emulator runs in emulation mode"

If you are on a mac you can install haxm using homebrew via cask which is a built-in extension (as of 2015) which allows installing non-open-source and desktop apps (i.e. chrome, firefox, eclipse, etc.):

brew cask install intel-haxm 

Android Studio

If you are using Android Studio then you can achieve the same result from the menu Tools ? SDK Manager, and then on the SDK Tools tab, select the checkbox for Intel x86 Emulator Accelerator (HAXM installer), and click Ok.

How to iterate over each string in a list of strings and operate on it's elements

for i,j in enumerate(words): # i---index of word----j
     #now you got index of your words (present in i)
     print(i) 

#1214 - The used table type doesn't support FULLTEXT indexes

Before MySQL 5.6 Full-Text Search is supported only with MyISAM Engine.

Therefore either change the engine for your table to MyISAM

CREATE TABLE gamemech_chat (
  id bigint(20) unsigned NOT NULL auto_increment,
  from_userid varchar(50) NOT NULL default '0',
  to_userid varchar(50) NOT NULL default '0',
  text text NOT NULL,
  systemtext text NOT NULL,
  timestamp datetime NOT NULL default '0000-00-00 00:00:00',
  chatroom bigint(20) NOT NULL default '0',
  PRIMARY KEY  (id),
  KEY from_userid (from_userid),
  FULLTEXT KEY from_userid_2 (from_userid),
  KEY chatroom (chatroom),
  KEY timestamp (timestamp)
) ENGINE=MyISAM;

Here is SQLFiddle demo

or upgrade to 5.6 and use InnoDB Full-Text Search.

SQL Server r2 installation error .. update Visual Studio 2008 to SP1

I used the Visual Studio 2008 Uninstall tool and it worked fine for me.

You can use this tool to uninstall Visual Studio 2008 official release and Visual Studio 2008 Release candidate (Only English version).

Found here, on the MSDN Forum: MSDN forum topic.

I found this answer here

Be sure you run the tool with admin-rights.

Has Facebook sharer.php changed to no longer accept detailed parameters?

I review your url in use:

https://www.facebook.com/sharer/sharer.php?s=100&p[title]=EXAMPLE&p[summary]=EXAMPLE&p[url]=EXAMPLE&p[images][0]=EXAMPLE

and see this differences:

  1. The sharer URL not is same.
  2. The strings are in different order. ( Do not know if this affects ).

I use this URL string:

http://www.facebook.com/sharer.php?s=100&p[url]=http://www.example.com/&p[images][0]=/images/image.jpg&p[title]=Title&p[summary]=Summary

In the "title" and "summary" section, I use the php function urlencode(); like this:

<?php echo urlencode($detail->title); ?>

And working fine for me.

500.21 Bad module "ManagedPipelineHandler" in its module list

This is because IIS 7 uses http handlers from both <system.web><httpHandlers> and <system.webServer><handlers>. if you need CloudConnectHandler in your application, you should add <httpHandlers> section with this handler to the <system.web>:

<httpHandlers>
    <add verb="*" path="CloudConnect.aspx" type="CloudConnectHandler" />
</httpHandlers>

and also add preCondition attribute to the handler in <system.webServer>:

<handlers>
  <add name="CloudConnectHandler" verb="*" path="CloudConnect.aspx" type="CloudConnectHandler" preCondition="integratedMode" />
</handlers>

Hope it helps

Slice indices must be integers or None or have __index__ method

Your debut and fin values are floating point values, not integers, because taille is a float.

Make those values integers instead:

item = plateau[int(debut):int(fin)]

Alternatively, make taille an integer:

taille = int(sqrt(len(plateau)))

Eclipse interface icons very small on high resolution screen in Windows 8.1

The below change works seamlessly.

Quoting from CrazyPenguin's reply

"For those, like me, who found that even on the new Eclipse it wasn't scaled, see here: swt-autoscale-tweaks Basically I added -Dswt.autoScale=quarter to my eclipse.ini file."

How to completely remove node.js from Windows

Scenario: Removing NodeJS when Windows has no Program Entry for your Node installation

I ran into a problem where my version of NodeJS (0.10.26) could NOT be uninstalled nor removed, because Programs & Features in Windows 7 (aka Add/Remove Programs) had no record of my having installed NodeJS... so there was no option to remove it short of manually deleting registry keys and files.

Command to verify your NodeJS version: node --version

I attempted to install the newest recommended version of NodeJS, but it failed at the end of the installation process and rolled back. Multiple versions of NodeJS also failed, and the installer likewise rolled them back as well. I could not upgrade NodeJS from the command line as I did not have SUDO installed.

SOLUTION: After spending several hours troubleshooting the problem, including upgrading NPM, I decided to reinstall the EXACT version of NodeJS on my system, over the top of the existing installation.

That solution worked, and it reinstalled NodeJS without any errors. Better yet, it also added an official entry in Add/Remove Programs dialogue.

Now that Windows was aware of the forgotten NodeJS installation, I was able to uninstall my existing version of NodeJS completely. I then successfully installed the newest recommended release of NodeJS for the Windows platform (version 4.4.5 as of this writing) without a roll-back initiating.

It took me a while to reach sucess, so I am posting this in case it helps anyone else with a similar issue.

Android Gradle plugin 0.7.0: "duplicate files during packaging of APK"

It's more than one error

Under apply plugin: 'android-library'

add this ::

android {
    packagingOptions {
        exclude 'META-INF/ASL2.0'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/NOTICE'
    }
}

In case of duplicate files it's easy, look inside the JAR under the META-INF dir and see what's causing the error. It could be multiple. In my case Couchbase Lite plugin. As you add more plugins, you will need more exceptions

Bootstrap 3 Carousel Not Working

Recently I was helping a friend to find why their carousel was not working. Controls would not work and images were not transitioning. I had a working sample on a page I had used and we went through all the code including checking the items above in this post. We pasted the "good" carousel into the same page and it still worked. Now, all css and bootstrap files were the same for both. The code was now identical, so all we could try was the images.

So, we replaced the images with two that were working in my sample. It worked. We replaced the two images with the first two that were originally not working, and it worked. We added back each image (all jpegs) one-by-one, and when we got to the seventh image (of 18) and the carousel failed. Weird. We removed this one image and continued to add the remaining images until they were all added and the carousel worked.

for reference, we were using jquery-3.3.1.slim.min.js and bootstrap/4.3.1/js/bootstrap.min.js on this site.

I do not know why an image would or could cause a carousel to malfunction, but it did. I couldn't find a reference to this cause elsewhere either, so I'm posting here for posterity in the hope that it might help someone else when other solutions fail.

Test carousel with limited set of "known-to-be-good" images.

Google Script to see if text contains a value

I had to add a .toString to the item in the values array. Without it, it would only match if the entire cell body matched the searchTerm.

function foo() {
    var ss = SpreadsheetApp.getActiveSpreadsheet();
    var s = ss.getSheetByName('spreadsheet-name');
    var r = s.getRange('A:A');
    var v = r.getValues();
    var searchTerm = 'needle';
    for(var i=v.length-1;i>=0;i--) {
        if(v[0,i].toString().indexOf(searchTerm) > -1) {
            // do something
        }
    }
};

Using SUMIFS with multiple AND OR conditions

With the following, it is easy to link the Cell address...

=SUM(SUMIFS(FAGLL03!$I$4:$I$1048576,FAGLL03!$A$4:$A$1048576,">="&INDIRECT("A"&ROW()),FAGLL03!$A$4:$A$1048576,"<="&INDIRECT("B"&ROW()),FAGLL03!$Q$4:$Q$1048576,E$2))

Can use address / substitute / Column functions as required to use Cell addresses in full DYNAMIC.

Turn Pandas Multi-Index into column

There may be situations when df.reset_index() cannot be used (e.g., when you need the index, too). In this case, use index.get_level_values() to access index values directly:

df['Trial'] = df.index.get_level_values(0)
df['measurement'] = df.index.get_level_values(1)

This will assign index values to individual columns and keep the index.

See the docs for further info.

mysqli::query(): Couldn't fetch mysqli

I had the same problem. I changed the localhost parameter in the mysqli object to '127.0.0.1' instead of writing 'localhost'. It worked; I’m not sure how or why.

$db_connection = new mysqli("127.0.0.1","root","","db_name");

Hope it helps.

Proper way to return JSON using node or Express

You can use a middleware to set the default Content-Type, and set Content-Type differently for particular APIs. Here is an example:

const express = require('express');
const app = express();

const port = process.env.PORT || 3000;

const server = app.listen(port);

server.timeout = 1000 * 60 * 10; // 10 minutes

// Use middleware to set the default Content-Type
app.use(function (req, res, next) {
    res.header('Content-Type', 'application/json');
    next();
});

app.get('/api/endpoint1', (req, res) => {
    res.send(JSON.stringify({value: 1}));
})

app.get('/api/endpoint2', (req, res) => {
    // Set Content-Type differently for this particular API
    res.set({'Content-Type': 'application/xml'});
    res.send(`<note>
        <to>Tove</to>
        <from>Jani</from>
        <heading>Reminder</heading>
        <body>Don't forget me this weekend!</body>
        </note>`);
})

bash "if [ false ];" returns true instead of false -- why?

I found that I can do some basic logic by running something like:

A=true
B=true
if ($A && $B); then
    C=true
else
    C=false
fi
echo $C

python: changing row index of pandas data frame

When you are not sure of the number of rows, then you can do it this way:

followers_df.index = range(len(followers_df))

Select multiple images from android gallery

Initialize instance:

private String imagePath;
private List<String> imagePathList;

In onActivityResult You have to write this, If-else 2 block. One for single image and another for multiple image.

if (requestCode == GALLERY_CODE && resultCode == RESULT_OK  && data != null){

    imagePathList = new ArrayList<>();

    if(data.getClipData() != null){

        int count = data.getClipData().getItemCount();
        for (int i=0; i<count; i++){

            Uri imageUri = data.getClipData().getItemAt(i).getUri();
            getImageFilePath(imageUri);
        }
    }
    else if(data.getData() != null){

        Uri imgUri = data.getData();
        getImageFilePath(imgUri);
    }
}

Most important part, Get Image Path from uri:

public void getImageFilePath(Uri uri) {

    File file = new File(uri.getPath());
    String[] filePath = file.getPath().split(":");
    String image_id = filePath[filePath.length - 1];

    Cursor cursor = getContentResolver().query(android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI, null, MediaStore.Images.Media._ID + " = ? ", new String[]{image_id}, null);
    if (cursor!=null) {
        cursor.moveToFirst();
        imagePath = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
        imagePathList.add(imagePath);
        cursor.close();
    }
}

Hope this can help you.

Wait on the Database Engine recovery handle failed. Check the SQL server error log for potential causes

In my case, setting SQL Server Database Engine service startup account to NT AUTHORITY\NETWORK SERVICE failed, but setting it to NT Authority\System allowed me to succesfully install my SQL Server 2016 STD instance.

Just check the following snapshot.

enter image description here

For further details, check @Shanky's answer at https://dba.stackexchange.com/a/71798/66179

Remember: you can avoid server rebooting using setup's SkipRules switch:

setup.exe /ACTION=INSTALL /SkipRules=RebootRequiredCheck

setup.exe /ACTION=UNINSTALL /SkipRules=RebootRequiredCheck

Bootstrap carousel width and height

Are you trying to make it responsive? If you are then I would just recommend the following:

.tales {
  width: 100%;
}
.carousel-inner{
  width:100%;
  max-height: 200px !important;
}

However, the best way to handle this responsively would be thru the use of media queries like such:

/* Smaller than standard 960 (devices and browsers) */
@media only screen and (max-width: 959px) {}

/* Tablet Portrait size to standard 960 (devices and browsers) */
@media only screen and (min-width: 768px) and (max-width: 959px) {}

/* All Mobile Sizes (devices and browser) */
@media only screen and (max-width: 767px) {}

/* Mobile Landscape Size to Tablet Portrait (devices and browsers) */
@media only screen and (min-width: 480px) and (max-width: 767px) {}

/* Mobile Portrait Size to Mobile Landscape Size (devices and browsers) */
@media only screen and (max-width: 479px) {}

Add a scrollbar to a <textarea>

You will need to give your textarea a set height and then set overflow-y

textarea
{
resize: none;
overflow-y: scroll;
height:300px;
}

Using intents to pass data between activities

I like to use this clean code to pass one value only:

startActivity(new Intent(context, YourActivity.class).putExtra("key","value"));

This make more simple to write and understandable code.

Is there a need for range(len(a))?

Sometimes, you really don't care about the collection itself. For instance, creating a simple model fit line to compare an "approximation" with the raw data:

fib_raw = [1, 1, 2, 3, 5, 8, 13, 21] # Fibonacci numbers

phi = (1 + sqrt(5)) / 2
phi2 = (1 - sqrt(5)) / 2

def fib_approx(n): return (phi**n - phi2**n) / sqrt(5)

x = range(len(data))
y = [fib_approx(n) for n in x]

# Now plot to compare fib_raw and y
# Compare error, etc

In this case, the values of the Fibonacci sequence itself were irrelevant. All we needed here was the size of the input sequence we were comparing with.

Select Pandas rows based on list index

Another way (although it is a longer code) but it is faster than the above codes. Check it using %timeit function:

df[df.index.isin([1,3])]

PS: You figure out the reason

enter image description here

How to hide first section header in UITableView (grouped style)

This is how to hide the first section header in UITableView (grouped style).

Swift 3.0 & Xcode 8.0 Solution

  1. The TableView's delegate should implement the heightForHeaderInSection method

  2. Within the heightForHeaderInSection method, return the least positive number. (not zero!)

    func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
    
        let headerHeight: CGFloat
    
        switch section {
        case 0:
            // hide the header
            headerHeight = CGFloat.leastNonzeroMagnitude
        default:
            headerHeight = 21
        }
    
        return headerHeight
    }
    

Populate data table from data reader

I looked into this as well, and after comparing the SqlDataAdapter.Fill method with the SqlDataReader.Load funcitons, I've found that the SqlDataAdapter.Fill method is more than twice as fast with the result sets I've been using

Used code:

    [TestMethod]
    public void SQLCommandVsAddaptor()
    {
        long AdapterFillLargeTableTime, readerLoadLargeTableTime, AdapterFillMediumTableTime, readerLoadMediumTableTime, AdapterFillSmallTableTime, readerLoadSmallTableTime, AdapterFillTinyTableTime, readerLoadTinyTableTime;

        string LargeTableToFill = "select top 10000 * from FooBar";
        string MediumTableToFill = "select top 1000 * from FooBar";
        string SmallTableToFill = "select top 100 * from FooBar";
        string TinyTableToFill = "select top 10 * from FooBar";

        using (SqlConnection sconn = new SqlConnection("Data Source=.;initial catalog=Foo;persist security info=True; user id=bar;password=foobar;"))
        {
            // large data set measurements
            AdapterFillLargeTableTime = MeasureExecutionTimeMethod(sconn, LargeTableToFill, ExecuteDataAdapterFillStep);
            readerLoadLargeTableTime = MeasureExecutionTimeMethod(sconn, LargeTableToFill, ExecuteSqlReaderLoadStep);
            // medium data set measurements
            AdapterFillMediumTableTime = MeasureExecutionTimeMethod(sconn, MediumTableToFill, ExecuteDataAdapterFillStep);
            readerLoadMediumTableTime = MeasureExecutionTimeMethod(sconn, MediumTableToFill, ExecuteSqlReaderLoadStep);
            // small data set measurements
            AdapterFillSmallTableTime = MeasureExecutionTimeMethod(sconn, SmallTableToFill, ExecuteDataAdapterFillStep);
            readerLoadSmallTableTime = MeasureExecutionTimeMethod(sconn, SmallTableToFill, ExecuteSqlReaderLoadStep);
            // tiny data set measurements
            AdapterFillTinyTableTime = MeasureExecutionTimeMethod(sconn, TinyTableToFill, ExecuteDataAdapterFillStep);
            readerLoadTinyTableTime = MeasureExecutionTimeMethod(sconn, TinyTableToFill, ExecuteSqlReaderLoadStep);
        }
        using (StreamWriter writer = new StreamWriter("result_sql_compare.txt"))
        {
            writer.WriteLine("10000 rows");
            writer.WriteLine("Sql Data Adapter 100 times table fill speed 10000 rows: {0} milliseconds", AdapterFillLargeTableTime);
            writer.WriteLine("Sql Data Reader 100 times table load speed 10000 rows: {0} milliseconds", readerLoadLargeTableTime);
            writer.WriteLine("1000 rows");
            writer.WriteLine("Sql Data Adapter 100 times table fill speed 1000 rows: {0} milliseconds", AdapterFillMediumTableTime);
            writer.WriteLine("Sql Data Reader 100 times table load speed 1000 rows: {0} milliseconds", readerLoadMediumTableTime);
            writer.WriteLine("100 rows");
            writer.WriteLine("Sql Data Adapter 100 times table fill speed 100 rows: {0} milliseconds", AdapterFillSmallTableTime);
            writer.WriteLine("Sql Data Reader 100 times table load speed 100 rows: {0} milliseconds", readerLoadSmallTableTime);
            writer.WriteLine("10 rows");
            writer.WriteLine("Sql Data Adapter 100 times table fill speed 10 rows: {0} milliseconds", AdapterFillTinyTableTime);
            writer.WriteLine("Sql Data Reader 100 times table load speed 10 rows: {0} milliseconds", readerLoadTinyTableTime);

        }
        Process.Start("result_sql_compare.txt");
    }

    private long MeasureExecutionTimeMethod(SqlConnection conn, string query, Action<SqlConnection, string> Method)
    {
        long time; // know C#
        // execute single read step outside measurement time, to warm up cache or whatever
        Method(conn, query);
        // start timing
        time = Environment.TickCount;
        for (int i = 0; i < 100; i++)
        {
            Method(conn, query);
        }
        // return time in milliseconds
        return Environment.TickCount - time;
    }

    private void ExecuteDataAdapterFillStep(SqlConnection conn, string query)
    {
        DataTable tab = new DataTable();
        conn.Open();
        using (SqlDataAdapter comm = new SqlDataAdapter(query, conn))
        {
            // Adapter fill table function
            comm.Fill(tab);
        }
        conn.Close();
    }

    private void ExecuteSqlReaderLoadStep(SqlConnection conn, string query)
    {
        DataTable tab = new DataTable();
        conn.Open();
        using (SqlCommand comm = new SqlCommand(query, conn))
        {
            using (SqlDataReader reader = comm.ExecuteReader())
            {
                // IDataReader Load function
                tab.Load(reader);
            }
        }
        conn.Close();
    }

Results:

10000 rows:
Sql Data Adapter 100 times table fill speed 10000 rows: 11782 milliseconds
Sql Data Reader  100 times table load speed 10000 rows: 26047 milliseconds
1000 rows:
Sql Data Adapter 100 times table fill speed 1000 rows: 984  milliseconds
Sql Data Reader  100 times table load speed 1000 rows: 2031 milliseconds
100 rows:
Sql Data Adapter 100 times table fill speed 100 rows: 125 milliseconds
Sql Data Reader  100 times table load speed 100 rows: 235 milliseconds
10 rows:
Sql Data Adapter 100 times table fill speed 10 rows: 32 milliseconds
Sql Data Reader  100 times table load speed 10 rows: 93 milliseconds

For performance issues, using the SqlDataAdapter.Fill method is far more efficient. So unless you want to shoot yourself in the foot use that. It works faster for small and large data sets.

TypeError: string indices must be integers, not str // working with dict

Actually I think that more general approach to loop through dictionary is to use iteritems():

# get tuples of term, courses
for term, term_courses in courses.iteritems():
    # get tuples of course number, info
    for course, info in term_courses.iteritems():
        # loop through info
        for k, v in info.iteritems():
            print k, v

output:

assistant Peter C.
prereq cs101
...
name Programming a Robotic Car
teacher Sebastian

Or, as Matthias mentioned in comments, if you don't need keys, you can just use itervalues():

for term_courses in courses.itervalues():
    for info in term_courses.itervalues():
        for k, v in info.iteritems():
            print k, v

MySQL : ERROR 1215 (HY000): Cannot add foreign key constraint

The syntax of FOREIGN KEY for CREATE TABLE is structured as follows:

FOREIGN KEY (index_col_name)
        REFERENCES table_name (index_col_name,...)

So your MySQL DDL should be:

 create table course (
        course_id varchar(7),
        title varchar(50),
        dept_name varchar(20),
        credits numeric(2 , 0 ),
        primary key (course_id),
        FOREIGN KEY (dept_name)
            REFERENCES department (dept_name)
    );

Also, in the department table dept_name should be VARCHAR(20)

More information can be found in the MySQL documentation

php resize image on upload

// This was my example that I used to automatically resize every inserted photo to 100 by 50 pixel and image format to jpeg hope this helps too

if($result){
$maxDimW = 100;
$maxDimH = 50;
list($width, $height, $type, $attr) = getimagesize( $_FILES['photo']['tmp_name'] );
if ( $width > $maxDimW || $height > $maxDimH ) {
    $target_filename = $_FILES['photo']['tmp_name'];
    $fn = $_FILES['photo']['tmp_name'];
    $size = getimagesize( $fn );
    $ratio = $size[0]/$size[1]; // width/height
    if( $ratio > 1) {
        $width = $maxDimW;
        $height = $maxDimH/$ratio;
    } else {
        $width = $maxDimW*$ratio;
        $height = $maxDimH;
    }
    $src = imagecreatefromstring(file_get_contents($fn));
    $dst = imagecreatetruecolor( $width, $height );
    imagecopyresampled($dst, $src, 0, 0, 0, 0, $width, $height, $size[0], $size[1] );

    imagejpeg($dst, $target_filename); // adjust format as needed


}

move_uploaded_file($_FILES['pdf']['tmp_name'],"pdf/".$_FILES['pdf']['name']);

Android Studio - How to increase Allocated Heap Size

-------EDIT--------

Android Studio 2.0 and above, you can create/edit this file by accessing "Edit Custom VM Options" from the Help menu.

-------ORIGINAL ANSWER--------

Open file located at

/Applications/Android\ Studio.app/Contents/bin/studio.vmoptions

Change the content to

-Xms128m
-Xmx4096m
-XX:MaxPermSize=1024m
-XX:ReservedCodeCacheSize=200m
-XX:+UseCompressedOops

Xmx specifies the maximum memory allocation pool for a Java Virtual Machine (JVM), while Xms specifies the initial memory allocation pool. Your JVM will be started with Xms amount of memory and will be able to use a maximum of Xmx amount of memory.

Save the studio.vmoptions file and restart Android Studio.

Note:

If you changed the heap size for the IDE, you must restart Android Studio before the new memory settings are applied. (source)

UICollectionView current visible cell index

You can use scrollViewDidEndDecelerating: for this

//@property (strong, nonatomic) IBOutlet UICollectionView *collectionView;

   - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{

        for (UICollectionViewCell *cell in [self.collectionView visibleCells]) {
            NSIndexPath *indexPath = [self.collectionView indexPathForCell:cell];
            NSUInteger lastIndex = [indexPath indexAtPosition:[indexPath length] - 1];
            NSLog(@"visible cell value %d",lastIndex);
        }

    }

Subset data to contain only columns whose names match a condition

Using dplyr you can:

df <- df %>% dplyr:: select(grep("ABC", names(df)), grep("XYZ", names(df)))

Is there a concise way to iterate over a stream with indices in Java 8?

As jean-baptiste-yunès said, if your stream is based on a java List then using an AtomicInteger and its incrementAndGet method is a very good solution to the problem and the returned integer does correspond to the index in the original List as long as you do not use a parallel stream.

Bootstrap 3 Carousel fading to new slide instead of sliding to new slide

Check this out : http://codepen.io/Rowno/pen/Afykb

.carousel-fade {
    .carousel-inner {
        .item {
            opacity: 0;
            transition-property: opacity;
        }

    .active {
        opacity: 1;
    }

    .active.left,
    .active.right {
        left: 0;
        opacity: 0;
        z-index: 1;
    }

    .next.left,
    .prev.right {
        opacity: 1;
    }
}

Works marvellously, I hope it works

commands not found on zsh

Uninstall and reinstall zsh worked for me:

sudo yum remove zsh
sudo yum install -y zsh

Run a JAR file from the command line and specify classpath

You can do these in unix shell:

java -cp MyJar.jar:lib/* com.somepackage.subpackage.Main

You can do these in windows powershell:

java -cp "MyJar.jar;lib\*" com.somepackage.subpackage.Main

How to display a json array in table format?

var data = [
    {
        id : "001",
        name : "apple",
        category : "fruit",
        color : "red"
    },
    {
        id : "002",
        name : "melon",
        category : "fruit",
        color : "green"
    },
    {
        id : "003",
        name : "banana",
        category : "fruit",
        color : "yellow"
    }
];

for(var i = 0, len = data.length; i < length; i++) {
    var temp = '<tr><td>' + data[i].id + '</td>';
    temp+= '<td>' + data[i].name+ '</td>';
    temp+= '<td>' + data[i].category + '</td>';
    temp+= '<td>' + data[i].color + '</td></tr>';
    $('table tbody').append(temp));
}

Bootstrap 3 Collapse show state with Chevron icon

To improve upon the answer with the most upticks, some of you may have noticed on the initial load of the page that the chevrons all point in the same direction. This is corrected by adding the class "collapsed" to elements that you want to load collapsed.

<div class="panel-group" id="accordion">
  <div class="panel panel-default">
    <div class="panel-heading">
      <h4 class="panel-title">
        <a class="accordion-toggle" data-toggle="collapse" data-parent="#accordion" href="#collapseOne">
          Collapsible Group Item #1
        </a>
      </h4>
    </div>
    <div id="collapseOne" class="panel-collapse collapse in">
      <div class="panel-body">
        Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
      </div>
    </div>
  </div>
  <div class="panel panel-default">
    <div class="panel-heading">
      <h4 class="panel-title">
        <a class="accordion-toggle collapsed" data-toggle="collapse" data-parent="#accordion" href="#collapseTwo">
          Collapsible Group Item #2
        </a>
      </h4>
    </div>
    <div id="collapseTwo" class="panel-collapse collapse">
      <div class="panel-body">
        Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
      </div>
    </div>
  </div>
  <div class="panel panel-default">
    <div class="panel-heading">
      <h4 class="panel-title">
        <a class="accordion-toggle collapsed" data-toggle="collapse" data-parent="#accordion" href="#collapseThree">
          Collapsible Group Item #3
        </a>
      </h4>
    </div>
    <div id="collapseThree" class="panel-collapse collapse">
      <div class="panel-body">
        Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
      </div>
    </div>
  </div>
</div>

Here is a working fiddle: http://jsfiddle.net/3gYa3/585/

How to check file MIME type with javascript before upload?

You can easily determine the file MIME type with JavaScript's FileReader before uploading it to a server. I agree that we should prefer server-side checking over client-side, but client-side checking is still possible. I'll show you how and provide a working demo at the bottom.


Check that your browser supports both File and Blob. All major ones should.

if (window.FileReader && window.Blob) {
    // All the File APIs are supported.
} else {
    // File and Blob are not supported
}

Step 1:

You can retrieve the File information from an <input> element like this (ref):

<input type="file" id="your-files" multiple>
<script>
var control = document.getElementById("your-files");
control.addEventListener("change", function(event) {
    // When the control has changed, there are new files
    var files = control.files,
    for (var i = 0; i < files.length; i++) {
        console.log("Filename: " + files[i].name);
        console.log("Type: " + files[i].type);
        console.log("Size: " + files[i].size + " bytes");
    }
}, false);
</script>

Here is a drag-and-drop version of the above (ref):

<div id="your-files"></div>
<script>
var target = document.getElementById("your-files");
target.addEventListener("dragover", function(event) {
    event.preventDefault();
}, false);

target.addEventListener("drop", function(event) {
    // Cancel default actions
    event.preventDefault();
    var files = event.dataTransfer.files,
    for (var i = 0; i < files.length; i++) {
        console.log("Filename: " + files[i].name);
        console.log("Type: " + files[i].type);
        console.log("Size: " + files[i].size + " bytes");
    }
}, false);
</script>

Step 2:

We can now inspect the files and tease out headers and MIME types.

✘ Quick method

You can naïvely ask Blob for the MIME type of whatever file it represents using this pattern:

var blob = files[i]; // See step 1 above
console.log(blob.type);

For images, MIME types come back like the following:

image/jpeg
image/png
...

Caveat: The MIME type is detected from the file extension and can be fooled or spoofed. One can rename a .jpg to a .png and the MIME type will be be reported as image/png.


✓ Proper header-inspecting method

To get the bonafide MIME type of a client-side file we can go a step further and inspect the first few bytes of the given file to compare against so-called magic numbers. Be warned that it's not entirely straightforward because, for instance, JPEG has a few "magic numbers". This is because the format has evolved since 1991. You might get away with checking only the first two bytes, but I prefer checking at least 4 bytes to reduce false positives.

Example file signatures of JPEG (first 4 bytes):

FF D8 FF E0 (SOI + ADD0)
FF D8 FF E1 (SOI + ADD1)
FF D8 FF E2 (SOI + ADD2)

Here is the essential code to retrieve the file header:

var blob = files[i]; // See step 1 above
var fileReader = new FileReader();
fileReader.onloadend = function(e) {
  var arr = (new Uint8Array(e.target.result)).subarray(0, 4);
  var header = "";
  for(var i = 0; i < arr.length; i++) {
     header += arr[i].toString(16);
  }
  console.log(header);

  // Check the file signature against known types

};
fileReader.readAsArrayBuffer(blob);

You can then determine the real MIME type like so (more file signatures here and here):

switch (header) {
    case "89504e47":
        type = "image/png";
        break;
    case "47494638":
        type = "image/gif";
        break;
    case "ffd8ffe0":
    case "ffd8ffe1":
    case "ffd8ffe2":
    case "ffd8ffe3":
    case "ffd8ffe8":
        type = "image/jpeg";
        break;
    default:
        type = "unknown"; // Or you can use the blob.type as fallback
        break;
}

Accept or reject file uploads as you like based on the MIME types expected.


Demo

Here is a working demo for local files and remote files (I had to bypass CORS just for this demo). Open the snippet, run it, and you should see three remote images of different types displayed. At the top you can select a local image or data file, and the file signature and/or MIME type will be displayed.

Notice that even if an image is renamed, its true MIME type can be determined. See below.

Screenshot

Expected output of demo


_x000D_
_x000D_
// Return the first few bytes of the file as a hex string_x000D_
function getBLOBFileHeader(url, blob, callback) {_x000D_
  var fileReader = new FileReader();_x000D_
  fileReader.onloadend = function(e) {_x000D_
    var arr = (new Uint8Array(e.target.result)).subarray(0, 4);_x000D_
    var header = "";_x000D_
    for (var i = 0; i < arr.length; i++) {_x000D_
      header += arr[i].toString(16);_x000D_
    }_x000D_
    callback(url, header);_x000D_
  };_x000D_
  fileReader.readAsArrayBuffer(blob);_x000D_
}_x000D_
_x000D_
function getRemoteFileHeader(url, callback) {_x000D_
  var xhr = new XMLHttpRequest();_x000D_
  // Bypass CORS for this demo - naughty, Drakes_x000D_
  xhr.open('GET', '//cors-anywhere.herokuapp.com/' + url);_x000D_
  xhr.responseType = "blob";_x000D_
  xhr.onload = function() {_x000D_
    callback(url, xhr.response);_x000D_
  };_x000D_
  xhr.onerror = function() {_x000D_
    alert('A network error occurred!');_x000D_
  };_x000D_
  xhr.send();_x000D_
}_x000D_
_x000D_
function headerCallback(url, headerString) {_x000D_
  printHeaderInfo(url, headerString);_x000D_
}_x000D_
_x000D_
function remoteCallback(url, blob) {_x000D_
  printImage(blob);_x000D_
  getBLOBFileHeader(url, blob, headerCallback);_x000D_
}_x000D_
_x000D_
function printImage(blob) {_x000D_
  // Add this image to the document body for proof of GET success_x000D_
  var fr = new FileReader();_x000D_
  fr.onloadend = function() {_x000D_
    $("hr").after($("<img>").attr("src", fr.result))_x000D_
      .after($("<div>").text("Blob MIME type: " + blob.type));_x000D_
  };_x000D_
  fr.readAsDataURL(blob);_x000D_
}_x000D_
_x000D_
// Add more from http://en.wikipedia.org/wiki/List_of_file_signatures_x000D_
function mimeType(headerString) {_x000D_
  switch (headerString) {_x000D_
    case "89504e47":_x000D_
      type = "image/png";_x000D_
      break;_x000D_
    case "47494638":_x000D_
      type = "image/gif";_x000D_
      break;_x000D_
    case "ffd8ffe0":_x000D_
    case "ffd8ffe1":_x000D_
    case "ffd8ffe2":_x000D_
      type = "image/jpeg";_x000D_
      break;_x000D_
    default:_x000D_
      type = "unknown";_x000D_
      break;_x000D_
  }_x000D_
  return type;_x000D_
}_x000D_
_x000D_
function printHeaderInfo(url, headerString) {_x000D_
  $("hr").after($("<div>").text("Real MIME type: " + mimeType(headerString)))_x000D_
    .after($("<div>").text("File header: 0x" + headerString))_x000D_
    .after($("<div>").text(url));_x000D_
}_x000D_
_x000D_
/* Demo driver code */_x000D_
_x000D_
var imageURLsArray = ["http://media2.giphy.com/media/8KrhxtEsrdhD2/giphy.gif", "http://upload.wikimedia.org/wikipedia/commons/e/e9/Felis_silvestris_silvestris_small_gradual_decrease_of_quality.png", "http://static.giantbomb.com/uploads/scale_small/0/316/520157-apple_logo_dec07.jpg"];_x000D_
_x000D_
// Check for FileReader support_x000D_
if (window.FileReader && window.Blob) {_x000D_
  // Load all the remote images from the urls array_x000D_
  for (var i = 0; i < imageURLsArray.length; i++) {_x000D_
    getRemoteFileHeader(imageURLsArray[i], remoteCallback);_x000D_
  }_x000D_
_x000D_
  /* Handle local files */_x000D_
  $("input").on('change', function(event) {_x000D_
    var file = event.target.files[0];_x000D_
    if (file.size >= 2 * 1024 * 1024) {_x000D_
      alert("File size must be at most 2MB");_x000D_
      return;_x000D_
    }_x000D_
    remoteCallback(escape(file.name), file);_x000D_
  });_x000D_
_x000D_
} else {_x000D_
  // File and Blob are not supported_x000D_
  $("hr").after( $("<div>").text("It seems your browser doesn't support FileReader") );_x000D_
} /* Drakes, 2015 */
_x000D_
img {_x000D_
  max-height: 200px_x000D_
}_x000D_
div {_x000D_
  height: 26px;_x000D_
  font: Arial;_x000D_
  font-size: 12pt_x000D_
}_x000D_
form {_x000D_
  height: 40px;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>_x000D_
<form>_x000D_
  <input type="file" />_x000D_
  <div>Choose an image to see its file signature.</div>_x000D_
</form>_x000D_
<hr/>
_x000D_
_x000D_
_x000D_

ImportError: No module named apiclient.discovery

I got this same error when working on a project to parse recent calendar events from Google Calendar.

Using the standard install with pip did not work for me, here is what I did to get the packages I needed.

Go directly to the source, here is a link for the google-api-python-client, but if you need a different language it should not be too different.

https://github.com/google/google-api-python-client

Click on the green "Clone or Download" button near the top left and save it as a zip file. Move the zip to your project folder and extract it there. Then cut all the files from the folder it creates back into the root of your project folder.

Yes, this does clutter your work space, but many compilers have ways to hide files.

After doing this the standard

from googleapiclient import discovery

works great.

Hope this helps.

How to get raw text from pdf file using java

Using pdfbox we can achive this

Example :

public static void main(String args[]) {

    PDFParser parser = null;
    PDDocument pdDoc = null;
    COSDocument cosDoc = null;
    PDFTextStripper pdfStripper;

    String parsedText;
    String fileName = "E:\\Files\\Small Files\\PDF\\JDBC.pdf";
    File file = new File(fileName);
    try {
        parser = new PDFParser(new FileInputStream(file));
        parser.parse();
        cosDoc = parser.getDocument();
        pdfStripper = new PDFTextStripper();
        pdDoc = new PDDocument(cosDoc);
        parsedText = pdfStripper.getText(pdDoc);
        System.out.println(parsedText.replaceAll("[^A-Za-z0-9. ]+", ""));
    } catch (Exception e) {
        e.printStackTrace();
        try {
            if (cosDoc != null)
                cosDoc.close();
            if (pdDoc != null)
                pdDoc.close();
        } catch (Exception e1) {
            e1.printStackTrace();
        }

    }
}

Combining two Series into a DataFrame in pandas

If you are trying to join Series of equal length but their indexes don't match (which is a common scenario), then concatenating them will generate NAs wherever they don't match.

x = pd.Series({'a':1,'b':2,})
y = pd.Series({'d':4,'e':5})
pd.concat([x,y],axis=1)

#Output (I've added column names for clarity)
Index   x    y
a      1.0  NaN
b      2.0  NaN
d      NaN  4.0
e      NaN  5.0

Assuming that you don't care if the indexes match, the solution is to reindex both Series before concatenating them. If drop=False, which is the default, then Pandas will save the old index in a column of the new dataframe (the indexes are dropped here for simplicity).

pd.concat([x.reset_index(drop=True),y.reset_index(drop=True)],axis=1)

#Output (column names added):
Index   x   y
0       1   4
1       2   5

SQL Server : Columns to Rows

Just to help new readers, I've created an example to better understand @bluefeet's answer about UNPIVOT.

 SELECT id
        ,entityId
        ,indicatorname
        ,indicatorvalue
  FROM (VALUES
        (1, 1, 'Value of Indicator 1 for entity 1', 'Value of Indicator 2 for entity 1', 'Value of Indicator 3 for entity 1'),
        (2, 1, 'Value of Indicator 1 for entity 2', 'Value of Indicator 2 for entity 2', 'Value of Indicator 3 for entity 2'),
        (3, 1, 'Value of Indicator 1 for entity 3', 'Value of Indicator 2 for entity 3', 'Value of Indicator 3 for entity 3'),
        (4, 2, 'Value of Indicator 1 for entity 4', 'Value of Indicator 2 for entity 4', 'Value of Indicator 3 for entity 4')
       ) AS Category(ID, EntityId, Indicator1, Indicator2, Indicator3)
UNPIVOT
(
    indicatorvalue
    FOR indicatorname IN (Indicator1, Indicator2, Indicator3)
) UNPIV;

printing a two dimensional array in python

There is always the easy way.

import numpy as np
print(np.matrix(A))

Which JDK version (Language Level) is required for Android Studio?

Try not to use JDK versions higher than the ones supported. I've actually ran into a very ambiguous problem a few months ago.

I had a jar library of my own that I compiled with JDK 8, and I was using it in my assignment. It was giving me some kind of preDexDebug error every time I tried running it. Eventually after hours of trying to decipher the error logs I finally had an idea of what was wrong. I checked the system requirements, changed compilers from 8 to 7, and it worked. Looks like putting my jar into a library cost me a few hours rather than save it...

How to change Status Bar text color in iOS

This is documented in the iOS 7 UI Transition Guide, which you need an Apple developer ID to access directly. The relevant excerpt:

Because the status bar is transparent, the view behind it shows through. [...] Use a UIStatusBarStyle constant to specify whether the statusbar content should be dark or light:

UIStatusBarStyleDefault displays dark content. [...]

UIStatusBarStyleLightContent displays light content. Use when dark content is behind the status bar.

Also possibly of interest:

In iOS 7, you can control the style of the status bar from an individual vew controller and change it while the app runs. To opt in to this behavior, add the UIViewControllerBasedStatusBarAppearance key to an app's Info.plist file and give it the value YES.

I'd definitely recommend having a look through the document, which, again, you can access with your Apple developer ID.

Java - Find shortest path between 2 points in a distance weighted map

You can see a complete example using java 8, recursion and streams -> Dijkstra algorithm with java

How do I evenly add space between a label and the input field regardless of length of text?

You can always use the 'pre' tag inside the label, and just enter the blank spaces in it, So you can always add the same or different number of spaces you require

<form>
<label>First Name :<pre>Here just enter number of spaces you want to use(I mean using spacebar to enter blank spaces)</pre>
<input type="text"></label>
<label>Last Name :<pre>Now Enter enter number of spaces to match above number of 
spaces</pre>
<input type="text"></label>
</form>

Hope you like my answer, It's a simple and efficient hack

Maven compile: package does not exist

the issue happened with me, I resolved by removing the scope tag only and built successfully.

R: "Unary operator error" from multiline ggplot2 command

It looks like you might have inserted an extra + at the beginning of each line, which R is interpreting as a unary operator (like - interpreted as negation, rather than subtraction). I think what will work is

ggplot(combined.data, aes(x = region, y = expression, fill = species)) +
    geom_boxplot() +
    scale_fill_manual(values = c("yellow", "orange")) + 
    ggtitle("Expression comparisons for ACTB") + 
    theme(axis.text.x = element_text(angle=90, face="bold", colour="black"))

Perhaps you copy and pasted from the output of an R console? The console uses + at the start of the line when the input is incomplete.

angular.element vs document.getElementById or jQuery selector with spin (busy) control

I don't think it's the right way to use angular. If a framework method doesnt exist, don't create it! This means the framework (here angular) doesnt work this way.

With angular you should not manipulate DOM like this (the jquery way), but use angular helper such as

<div ng-show="isLoading" class="loader"></div>

Or create your own directive (your own DOM component) in order to have full control on it.

BTW, you can see here http://caniuse.com/#search=queryselector querySelector is well supported and so can be use safely.

openssl s_client -cert: Proving a client certificate was sent to the server

I know this is an old question but it does not yet appear to have an answer. I've duplicated this situation, but I'm writing the server app, so I've been able to establish what happens on the server side as well. The client sends the certificate when the server asks for it and if it has a reference to a real certificate in the s_client command line. My server application is set up to ask for a client certificate and to fail if one is not presented. Here is the command line I issue:

Yourhostname here -vvvvvvvvvv s_client -connect <hostname>:443 -cert client.pem -key cckey.pem -CAfile rootcert.pem -cipher ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH -tls1 -state

When I leave out the "-cert client.pem" part of the command the handshake fails on the server side and the s_client command fails with an error reported. I still get the report "No client certificate CA names sent" but I think that has been answered here above.

The short answer then is that the server determines whether a certificate will be sent by the client under normal operating conditions (s_client is not normal) and the failure is due to the server not recognizing the CA in the certificate presented. I'm not familiar with many situations in which two-way authentication is done although it is required for my project.

You are clearly sending a certificate. The server is clearly rejecting it.

The missing information here is the exact manner in which the certs were created and the way in which the provider loaded the cert, but that is probably all wrapped up by now.

Fixed height and width for bootstrap carousel

Apply following style to carousel listbox.

_x000D_
_x000D_
<div class="carousel-inner" role="listbox" style=" width:100%; height: 500px !important;">_x000D_
_x000D_
..._x000D_
_x000D_
</div
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Change background color of selected item on a ListView

For those wondering what EXACTLY needs to be done to keep rows selected even as you scroll up down. It's the state_activated The rest is taken care of by internal functionality, you don't have to worry about toggle, and can select multiple items. I didn't need to use notifyDataSetChanged() or setSelected(true) methods.

Add this line to your selector file, for me drawable\row_background.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:drawable="@android:color/holo_blue_light"/>

    <item android:state_enabled="true" android:state_pressed="true" android:drawable="@android:color/holo_blue_light" />
    <item android:state_enabled="true" android:state_focused="true" android:drawable="@android:color/holo_blue_bright" />
    <item android:state_enabled="true" android:state_selected="true" android:drawable="@android:color/holo_blue_light" />
    <item android:state_activated="true" android:drawable="@android:color/holo_blue_light" />

    <item android:drawable="@android:color/transparent"/>
</selector>

Then in layout\custom_row.xml

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:padding="10dip"
        android:background="@drawable/row_background"
        android:orientation="vertical">
  <TextView
        android:id="@+id/line1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

For more information, I'm using this with ListView Adapter, using myList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL); and myList.setMultiChoiceModeListener(new MultiChoiceModeListener()...

from this example: http://www.androidbegin.com/tutorial/android-delete-multiple-selected-items-listview-tutorial/

Also, you (should) use this structure for your list-adapter coupling: List myList = new ArrayList();

instead of: ArrayList myList = new ArrayList();

Explanation: Type List vs type ArrayList in Java

How to refresh Gridview after pressed a button in asp.net

All you have to do is In your bLoanButton_Click , add a line to rebind the Grid to the SqlDataSource :

protected void bLoanButton_Click(object sender, EventArgs e)
{

//your same code
........

GridView1.DataBind();


}

regards

Preventing multiple clicks on button

Disable pointer events in the first line of your callback, and then resume them on the last line.

element.on('click', function() {
  element.css('pointer-events', 'none'); 
  //do all of your stuff
  element.css('pointer-events', 'auto');   
};

Finding the indices of matching elements in list in Python

>>> average =  [1,3,2,1,1,0,24,23,7,2,727,2,7,68,7,83,2]
>>> matches = [i for i in range(0,len(average)) if average[i]<2 or average[i]>4]
>>> matches
[0, 3, 4, 5, 6, 7, 8, 10, 12, 13, 14, 15]

How to compare each item in a list with the rest, only once?

Your solution is correct, but your outer loop is still longer than needed. You don't need to compare the last element with anything else because it's been already compared with all the others in the previous iterations. Your inner loop still prevents that, but since we're talking about collision detection you can save the unnecessary check.

Using the same language you used to illustrate your algorithm, you'd come with something like this:

for (int i = 0, i < mylist.size() - 1; ++i)
    for (int j = i + 1, j < mylist.size(); --j)
        compare(mylist[i], mylist[j])

Appending to an empty DataFrame in Pandas?

You can concat the data in this way:

InfoDF = pd.DataFrame()
tempDF = pd.DataFrame(rows,columns=['id','min_date'])

InfoDF = pd.concat([InfoDF,tempDF])

Is it possible to use argsort in descending order?

An elegant way could be as follows -

ids = np.flip(np.argsort(avgDists))

This will give you indices of elements sorted in descending order. Now you can use regular slicing...

top_n = ids[:n]

How to dump raw RTSP stream to file?

With this command I had poor image quality

ffmpeg -i rtsp://192.168.XXX.XXX:554/live.sdp -vcodec copy -acodec copy -f mp4 -y MyVideoFFmpeg.mp4

With this, almost without delay, I got good image quality.

ffmpeg -i rtsp://192.168.XXX.XXX:554/live.sdp -b 900k -vcodec copy -r 60 -y MyVdeoFFmpeg.avi

Concatenate two slices in Go

I would like to emphasize @icza answer and simplify it a bit since it is a crucial concept. I assume that reader is familiar with slices.

c := append(a, b...)

This is a valid answer to the question. BUT if you need to use slices 'a' and 'c' later in code in different context, this is not the safe way to concatenate slices.

To explain, lets read the expression not in terms of slices, but in terms of underlying arrays:

"Take (underlying) array of 'a' and append elements from array 'b' to it. If array 'a' has enough capacity to include all elements from 'b' - underlying array of 'c' will not be a new array, it will actually be array 'a'. Basically, slice 'a' will show len(a) elements of underlying array 'a', and slice 'c' will show len(c) of array 'a'."

append() does not necessarily create a new array! This can lead to unexpected results. See Go Playground example.

Always use make() function if you want to make sure that new array is allocated for the slice. For example here are few ugly but efficient enough options for the task.

la := len(a)
c := make([]int, la, la + len(b))
_ = copy(c, a)
c = append(c, b...)

la := len(a)
c := make([]int, la + len(b))
_ = copy(c, a)
_ = copy(c[la:], b)

Accessing JSON elements

Just for more one option...You can do it this way too:

MYJSON = {
    'username': 'gula_gut',
    'pics': '/0/myfavourite.jpeg',
    'id': '1'
}

#changing username
MYJSON['username'] = 'calixto'
print(MYJSON['username'])

I hope this can help.

How to display a range input slider vertically

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_x000D_
window.onload = function(){
var slider = document.getElementById("sss");
 var  result = document.getElementById("final");
slider.oninput = function(){
    result.innerHTML = slider.value ;
}
}
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.slider{
    width: 100vw;
    height: 100vh;
   
    display: flex;
    justify-content: center;
    align-items: center;
}

.slider .container-slider{
    width: 600px;
    display: flex;
    justify-content: center;
    align-items: center;
    transform: rotate(90deg)
}

.slider .container-slider input[type="range"]{
    width: 60%;
    -webkit-appearance: none;
    background-color: blue;
    height: 7px;
    border-radius: 5px;;
    outline: none;
    margin: 0 20px
    
}

.slider .container-slider input[type="range"]::-webkit-slider-thumb{
    -webkit-appearance: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: red;
}



.slider .container-slider input[type="range"]::-webkit-slider-thumb:hover{

box-shadow: 0px 0px 10px rgba(255,255,255,.3),
            0px 0px 15px rgba(255,255,255,.4),
            0px 0px 20px rgba(255,255,255,.5),
            0px 0px 25px rgba(255,255,255,.6),
            0px 0px 30px rgba(255,255,255,.7)

}


.slider .container-slider .val {
    width: 60px;
    height: 40px;
    background-color: #ACB6E5;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: consolas;
    font-weight: 700;
    font-size: 20px;
    letter-spacing: 1.3px;
    transform: rotate(-90deg)
}

.slider .container-slider .val::before{
    content: "";
    position: absolute;
    width: 0;
    height: 0;
    display: block;
    border: 20px solid transparent;
    border-bottom-color: #ACB6E5;
    top: -30px;
}
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<div class="slider">
  <div class="container-slider">
    <input type="range" min="0" max="100" step="1" value="" id="sss">
    <div class="val" id="final">0</div>
  </div>
</div>
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When should I use UNSIGNED and SIGNED INT in MySQL?

For negative integer value, SIGNED is used and for non-negative integer value, UNSIGNED is used. It always suggested to use UNSIGNED for id as a PRIMARY KEY.

How to check if a file exists in the Documents directory in Swift?

Swift 4 example:

var filePath: String {
    //manager lets you examine contents of a files and folders in your app.
    let manager = FileManager.default

    //returns an array of urls from our documentDirectory and we take the first
    let url = manager.urls(for: .documentDirectory, in: .userDomainMask).first
    //print("this is the url path in the document directory \(String(describing: url))")

    //creates a new path component and creates a new file called "Data" where we store our data array
    return(url!.appendingPathComponent("Data").path)
}

I put the check in my loadData function which I called in viewDidLoad.

override func viewDidLoad() {
    super.viewDidLoad()

    loadData()
}

Then I defined loadData below.

func loadData() {
    let manager = FileManager.default

    if manager.fileExists(atPath: filePath) {
        print("The file exists!")

        //Do what you need with the file. 
        ourData = NSKeyedUnarchiver.unarchiveObject(withFile: filePath) as! Array<DataObject>         
    } else {
        print("The file DOES NOT exist! Mournful trumpets sound...")
    }
}

Display an image into windows forms

There could be many reasons for this. A few that come up quickly to my mind:

  1. Did you call this routine AFTER InitializeComponent()?
  2. Is the path syntax you are using correct? Does it work if you try it in the debugger? Try using backslash (\) instead of Slash (/) and see.
  3. This may be due to side-effects of some other code in your form. Try using the same code in a blank Form (with just the constructor and this function) and check.

Maximum Java heap size of a 32-bit JVM on a 64-bit OS

As to why a 32-bit JVM is used instead of a 64-bit one, the reason is not technical but rather administrative/bureaucratic ...

When I was working for BEA, we found that the average application actually ran slower in a 64-bit JVM, then it did when running in a 32-bit JVM. In some cases, the performance hit was as high as 25% slower. So, unless your application really needs all that extra memory, you were better off setting up more 32-bit servers.

As I recall, the three most common technical justifications for using a 64-bit that BEA professional services personnel ran into were:

  1. The application was manipulating multiple massive images,
  2. The application was doing massive number crunching,
  3. The application had a memory leak, the customer was the prime on a government contract, and they didn't want to take the time and the expense of tracking down the memory leak. (Using a massive memory heap would increase the MTBF and the prime would still get paid)

.

Autoplay an audio with HTML5 embed tag while the player is invisible

"Sensitive" era

Modern browsers today seem to block (by default) these autoplay features. They are somewhat treated as pop-ops. Very intrusive. So yeah, users now have the complete control on when the sounds are played. [1,2,3]

HTML5 era

<audio controls autoplay loop hidden>
    <source src="audio.mp3" type="audio/mpeg">
</audio>

Early days of HTML

<embed src="audio.mp3" style="visibility:hidden" />

References

  1. Jer Noble, New <video> Policies for iOS, WebKit, link
  2. Allow or block media autoplay in Firefox, FireFox Help, link
  3. Mounir Lamouri, Unified autoplay, Chromium Blog, link
  4. Embedded content, World Wide Web Consortium, link

What is the purpose of XSD files?

XSD files are used to validate that XML files conform to a certain format.

In that respect they are similar to DTDs that existed before them.

The main difference between XSD and DTD is that XSD is written in XML and is considered easier to read and understand.

What is the default value for Guid?

To extend answers above, you cannot use Guid default value with Guid.Empty as an optional argument in method, indexer or delegate definition, because it will give you compile time error. Use default(Guid) or new Guid() instead.

Python 3 - Encode/Decode vs Bytes/Str

To add to Lennart Regebro's answer There is even the third way that can be used:

encoded3 = str.encode(original, 'utf-8')
print(encoded3)

Anyway, it is actually exactly the same as the first approach. It may also look that the second way is a syntactic sugar for the third approach.


A programming language is a means to express abstract ideas formally, to be executed by the machine. A programming language is considered good if it contains constructs that one needs. Python is a hybrid language -- i.e. more natural and more versatile than pure OO or pure procedural languages. Sometimes functions are more appropriate than the object methods, sometimes the reverse is true. It depends on mental picture of the solved problem.

Anyway, the feature mentioned in the question is probably a by-product of the language implementation/design. In my opinion, this is a nice example that show the alternative thinking about technically the same thing.

In other words, calling an object method means thinking in terms "let the object gives me the wanted result". Calling a function as the alternative means "let the outer code processes the passed argument and extracts the wanted value".

The first approach emphasizes the ability of the object to do the task on its own, the second approach emphasizes the ability of an separate algoritm to extract the data. Sometimes, the separate code may be that much special that it is not wise to add it as a general method to the class of the object.

How to initialize an array in angular2 and typescript

hi @JackSlayer94 please find the below example to understand how to make an array of size 5.

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class Hero {_x000D_
    name: string;_x000D_
    constructor(text: string) {_x000D_
        this.name = text;_x000D_
    }_x000D_
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    display() {_x000D_
        return "Hello, " + this.name;_x000D_
    }_x000D_
_x000D_
}_x000D_
_x000D_
let heros:Hero[] = new Array(5);_x000D_
for (let i = 0; i < 5; i++){_x000D_
    heros[i] = new Hero("Name: " + i);_x000D_
}_x000D_
_x000D_
for (let i = 0; i < 5; i++){_x000D_
    console.log(heros[i].display());_x000D_
}
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Restore DB — Error RESTORE HEADERONLY is terminating abnormally.

My guess is that you are trying to restore in lower versions which wont work

Increment a value in Postgres

UPDATE totals 
   SET total = total + 1
WHERE name = 'bill';

If you want to make sure the current value is indeed 203 (and not accidently increase it again) you can also add another condition:

UPDATE totals 
   SET total = total + 1
WHERE name = 'bill'
  AND total = 203;

python, sort descending dataframe with pandas

from pandas import DataFrame
import pandas as pd

d = {'one':[2,3,1,4,5],
 'two':[5,4,3,2,1],
 'letter':['a','a','b','b','c']}

df = DataFrame(d)

test = df.sort_values(['one'], ascending=False)
test

What are the differences between a pointer variable and a reference variable in C++?

Beside all the answers here,

you can implement operator overloading using references:

my_point operator+(const my_point& a, const my_point& b)
{
  return { a.x + b.x, a.y + b.y };
}

Using parameters as value would create temporary copies of the original arguments and using pointers would not invoke this function because of pointers arithmetics.

jQuery Selector: Id Ends With?

It's safer to add the underscore or $ to the term you're searching for so it's less likely to match other elements which end in the same ID:

$("element[id$=_txtTitle]")

(where element is the type of element you're trying to find - eg div, input etc.

(Note, you're suggesting your IDs tend to have $ signs in them, but I think .NET 2 now tends to use underscores in the ID instead, so my example uses an underscore).

Javascript - Replace html using innerHTML

You are replacing the starting tag and then putting that back in innerHTML, so the code will be invalid. Make all the replacements before you put the code back in the element:

var html = strMessage1.innerHTML;
html = html.replace( /aaaaaa./g,'<a href=\"http://www.google.com/');
html = html.replace( /.bbbbbb/g,'/world\">Helloworld</a>');
strMessage1.innerHTML = html;

HTML input file selection event not firing upon selecting the same file

Clearing the value of 0th index of input worked for me. Please try the below code, hope this will work (AngularJs).

          scope.onClick = function() {
            input[0].value = "";
                input.click();
            };

How do I replace text inside a div element?

el.innerHTML='';
el.appendChild(document.createTextNode("yo"));

Cannot read property length of undefined

The id of the input seems is not WallSearch. Maybe you're confusing that name and id. They are two different properties. name is used to define the name by which the value is posted, while id is the unique identification of the element inside the DOM.

Other possibility is that you have two elements with the same id. The browser will pick any of these (probably the last, maybe the first) and return an element that doesn't support the value property.

When should I use double or single quotes in JavaScript?

As stated by other replies, they are almost the same. But I will try to add more.

  1. Some efficient algorithms use character arrays to process strings. Those algorithms (browser compiler, etc.) would see " (#34) first before ' (#39) therefore saving several CPU cycles depending on your data structure.
  2. " is escaped by anti-XSS engines

Set ANDROID_HOME environment variable in mac

Firstly, get the Android SDK location in Android Studio : Android Studio -> Preferences -> Appearance & Behaviour -> System Settings -> Android SDK -> Android SDK Location

Then execute the following commands in terminal

export ANDROID_HOME=Paste here your SDK location

export PATH=$PATH:$ANDROID_HOME/bin

It is done.

How to tell if a file is git tracked (by shell exit code)?

try:

git ls-files --error-unmatch <file name>

will exit with 1 if file is not tracked

How to read a file from jar in Java?

If you want to read that file from inside your application use:

InputStream input = getClass().getResourceAsStream("/classpath/to/my/file");

The path starts with "/", but that is not the path in your file-system, but in your classpath. So if your file is at the classpath "org.xml" and is called myxml.xml your path looks like "/org/xml/myxml.xml".

The InputStream reads the content of your file. You can wrap it into an Reader, if you want.

I hope that helps.

How to open a new form from another form

Use this.Hide() instead of this.Close()

Format an Integer using Java String Format

Use %03d in the format specifier for the integer. The 0 means that the number will be zero-filled if it is less than three (in this case) digits.

See the Formatter docs for other modifiers.

EXCEL VBA, inserting blank row and shifting cells

If you want to just shift everything down you can use:

Rows(1).Insert shift:=xlShiftDown

Similarly to shift everything over:

Columns(1).Insert shift:=xlShiftRight

Are arrays passed by value or passed by reference in Java?

Your question is based on a false premise.

Arrays are not a primitive type in Java, but they are not objects either ... "

In fact, all arrays in Java are objects1. Every Java array type has java.lang.Object as its supertype, and inherits the implementation of all methods in the Object API.

... so are they passed by value or by reference? Does it depend on what the array contains, for example references or a primitive type?

Short answers: 1) pass by value, and 2) it makes no difference.

Longer answer:

Like all Java objects, arrays are passed by value ... but the value is the reference to the array. So, when you assign something to a cell of the array in the called method, you will be assigning to the same array object that the caller sees.

This is NOT pass-by-reference. Real pass-by-reference involves passing the address of a variable. With real pass-by-reference, the called method can assign to its local variable, and this causes the variable in the caller to be updated.

But not in Java. In Java, the called method can update the contents of the array, and it can update its copy of the array reference, but it can't update the variable in the caller that holds the caller's array reference. Hence ... what Java is providing is NOT pass-by-reference.

Here are some links that explain the difference between pass-by-reference and pass-by-value. If you don't understand my explanations above, or if you feel inclined to disagree with the terminology, you should read them.

Related SO question:

Historical background:

The phrase "pass-by-reference" was originally "call-by-reference", and it was used to distinguish the argument passing semantics of FORTRAN (call-by-reference) from those of ALGOL-60 (call-by-value and call-by-name).

  • In call-by-value, the argument expression is evaluated to a value, and that value is copied to the called method.

  • In call-by-reference, the argument expression is partially evaluated to an "lvalue" (i.e. the address of a variable or array element) that is passed to the calling method. The calling method can then directly read and update the variable / element.

  • In call-by-name, the actual argument expression is passed to the calling method (!!) which can evaluate it multiple times (!!!). This was complicated to implement, and could be used (abused) to write code that was very difficult to understand. Call-by-name was only ever used in Algol-60 (thankfully!).

UPDATE

Actually, Algol-60's call-by-name is similar to passing lambda expressions as parameters. The wrinkle is that these not-exactly-lambda-expressions (they were referred to as "thunks" at the implementation level) can indirectly modify the state of variables that are in scope in the calling procedure / function. That is part of what made them so hard to understand. (See the Wikipedia page on Jensen's Device for example.)


1. Nothing in the linked Q&A (Arrays in Java and how they are stored in memory) either states or implies that arrays are not objects.

How can I use JSON data to populate the options of a select box?

zeusstl is right. it works for me too.

   <select class="form-control select2" id="myselect">
                      <option disabled="disabled" selected></option>
                      <option>Male</option>
                      <option>Female</option>
                    </select>

   $.getJSON("mysite/json1.php", function(json){
        $('#myselect').empty();
        $('#myselect').append($('<option>').text("Select"));
        $.each(json, function(i, obj){

  $('#myselect').append($('<option>').text(obj.text).attr('value', obj.val));
        });
  });

How to prevent http file caching in Apache httpd (MAMP)

I had the same issue, but I found a good solution here: Stop caching for PHP 5.5.3 in MAMP

Basically find the php.ini file and comment out the OPCache lines. I hope this alternative answer helps others else out as well.

How to convert URL parameters to a JavaScript object?

One simple answer with build in native Node module.(No third party npm modules)

The querystring module provides utilities for parsing and formatting URL query strings. It can be accessed using:

const querystring = require('querystring');

const body = "abc=foo&def=%5Basf%5D&xyz=5"
const parseJSON = querystring.parse(body);
console.log(parseJSON);

Check if record exists from controller in Rails

When you call Business.where(:user_id => current_user.id) you will get an array. This Array may have no objects or one or many objects in it, but it won't be null. Thus the check == nil will never be true.

You can try the following:

if Business.where(:user_id => current_user.id).count == 0

So you check the number of elements in the array and compare them to zero.

or you can try:

if Business.find_by_user_id(current_user.id).nil?

this will return one or nil.

Checking session if empty or not

Use this if the session variable emp_num will store a string:

 if (!string.IsNullOrEmpty(Session["emp_num"] as string))
 {
                //The code
 }

If it doesn't store a string, but some other type, you should just check for null before accessing the value, as in your second example.

Web Service vs WCF Service

From What's the Difference between WCF and Web Services?

WCF is a replacement for all earlier web service technologies from Microsoft. It also does a lot more than what is traditionally considered as "web services".

WCF "web services" are part of a much broader spectrum of remote communication enabled through WCF. You will get a much higher degree of flexibility and portability doing things in WCF than through traditional ASMX because WCF is designed, from the ground up, to summarize all of the different distributed programming infrastructures offered by Microsoft. An endpoint in WCF can be communicated with just as easily over SOAP/XML as it can over TCP/binary and to change this medium is simply a configuration file mod. In theory, this reduces the amount of new code needed when porting or changing business needs, targets, etc.

ASMX is older than WCF, and anything ASMX can do so can WCF (and more). Basically you can see WCF as trying to logically group together all the different ways of getting two apps to communicate in the world of Microsoft; ASMX was just one of these many ways and so is now grouped under the WCF umbrella of capabilities.

Web Services can be accessed only over HTTP & it works in stateless environment, where WCF is flexible because its services can be hosted in different types of applications. Common scenarios for hosting WCF services are IIS,WAS, Self-hosting, Managed Windows Service.

The major difference is that Web Services Use XmlSerializer. But WCF Uses DataContractSerializer which is better in performance as compared to XmlSerializer.

Can someone explain mappedBy in JPA and Hibernate?

mappedby speaks for itself, it tells hibernate not to map this field. it's already mapped by this field [name="field"].
field is in the other entity (name of the variable in the class not the table in the database)..

If you don't do that, hibernate will map this two relation as it's not the same relation

so we need to tell hibernate to do the mapping in one side only and co-ordinate between them.

IFrame: This content cannot be displayed in a frame

The X-Frame-Options is defined in the Http Header and not in the <head> section of the page you want to use in the iframe.

Accepted values are: DENY, SAMEORIGIN and ALLOW-FROM "url"

How to put a jpg or png image into a button in HTML

This may work for you, try it and see if it works:

<input type="image" src="/library/graphics/cecb2.gif">

Initializing an Array of Structs in C#

I'd use a static constructor on the class that sets the value of a static readonly array.

public class SomeClass
{
   public readonly MyStruct[] myArray;

   public static SomeClass()
   {
      myArray = { {"foo", "bar"},
                  {"boo", "far"}};
   }
}

Draw Circle using css alone

yup.. here's my code:

<style>
  .circle{
     width: 100px;
     height: 100px;
     border-radius: 50%;
     background-color: blue
  }
</style>
<div class="circle">
</div>

Bootstrap 4 - Glyphicons migration?

The glyphicons.less file from Bootstrap 3 is available on GitHub. https://github.com/twbs/bootstrap/blob/master/less/glyphicons.less

It needs these variables:

@icon-font-path:          "../fonts/";
@icon-font-name:          "glyphicons-halflings-regular";
@icon-font-svg-id:        "glyphicons_halflingsregular";

Then you can convert the .less file to a .css file which you can use directly. You can do this online on lesscss.org/less-preview/. Here I've done it for you, save it as glyphicons.css and include it in your HTML files.

<link href="/Content/glyphicons.css" rel="stylesheet" />

You also need the Glyphicon fonts which is in the Bootstrap 3 package, place them in a /fonts/ directory.

Now you can just keep on using Glyphicons with Bootstrap 4 as usual.

Activating Anaconda Environment in VsCode

As I was not able to solve my problem by suggested ways, I will share how I fixed it.

First of all, even if I was able to activate an environment, the corresponding environment folder was not present in C:\ProgramData\Anaconda3\envs directory.

So I created a new anaconda environment using Anaconda prompt, a new folder named same as your given environment name will be created in the envs folder.

Next, I activated that environment in Anaconda prompt. Installed python with conda install python command.

Then on anaconda navigator, selected the newly created environment in the 'Applications on' menu. Launched vscode through Anaconda navigator.

Now as suggested by other answers, in vscode, opened command palette with Ctrl + Shift + P keyboard shortcut. Searched and selected Python: Select Interpreter

If the interpreter with newly created environment isn't listed out there, select Enter Interpreter Path and choose the newly created python.exe which is located similar to C:\ProgramData\Anaconda3\envs\<your-new-env>\ . So the total path will look like C:\ProgramData\Anaconda3\envs\<your-nev-env>\python.exe

Next time onwards the interpreter will be automatically listed among other interpreters.

Now you might see your selected conda environment at bottom left side in vscode.

Angular CLI Error: The serve command requires to be run in an Angular project, but a project definition could not be found

Angular Cli Error: The serve command requires to be run in an Angular project, but a project definition could not be found

Problem was missing angular.json files.

    ng update --all --force

Tested in Angular 7+

How to return images in flask response?

You use something like

from flask import send_file

@app.route('/get_image')
def get_image():
    if request.args.get('type') == '1':
       filename = 'ok.gif'
    else:
       filename = 'error.gif'
    return send_file(filename, mimetype='image/gif')

to send back ok.gif or error.gif, depending on the type query parameter. See the documentation for the send_file function and the request object for more information.

How create a new deep copy (clone) of a List<T>?

C# 9 records and with expressions can make it a little easier, especially if your type has many properties.

You can use something like:

var books2 = books1.Select(b => b with { }).ToList();

I did this as an example:

record Book
{
    public string Name { get; set; }
}

static void Main()
{
    List<Book> books1 = new List<Book>()
    {
        new Book { Name = "Book1.1" },
        new Book { Name = "Book1.2" },
        new Book { Name = "Book1.3" }
    };

    var books2 = books1.Select(b => b with { }).ToList();

    books2[0].Name = "Changed";
    books2[1].Name = "Changed";

    Console.WriteLine("Book1");
    foreach (var item in books1)
    {
        Console.WriteLine(item);
    }

    Console.WriteLine("Book2");
    foreach (var item in books2)
    {
        Console.WriteLine(item);
    }
}

And the result was:

Book1

Book { Name = Book1.1 }

Book { Name = Book1.2 }

Book { Name = Book1.3 }

Book2

Book { Name = Changed }

Book { Name = Changed }

Book { Name = Book1.3 }

How can I URL encode a string in Excel VBA?

No, nothing built-in (until Excel 2013 - see this answer).

There are three versions of URLEncode() in this answer.

  • A function with UTF-8 support. You should probably use this one (or the alternative implementation by Tom) for compatibility with modern requirements.
  • For reference and educational purposes, two functions without UTF-8 support:
    • one found on a third party website, included as-is. (This was the first version of the answer)
    • one optimized version of that, written by me

A variant that supports UTF-8 encoding and is based on ADODB.Stream (include a reference to a recent version of the "Microsoft ActiveX Data Objects" library in your project):

Public Function URLEncode( _
   ByVal StringVal As String, _
   Optional SpaceAsPlus As Boolean = False _
) As String
  Dim bytes() As Byte, b As Byte, i As Integer, space As String

  If SpaceAsPlus Then space = "+" Else space = "%20"

  If Len(StringVal) > 0 Then
    With New ADODB.Stream
      .Mode = adModeReadWrite
      .Type = adTypeText
      .Charset = "UTF-8"
      .Open
      .WriteText StringVal
      .Position = 0
      .Type = adTypeBinary
      .Position = 3 ' skip BOM
      bytes = .Read
    End With

    ReDim result(UBound(bytes)) As String

    For i = UBound(bytes) To 0 Step -1
      b = bytes(i)
      Select Case b
        Case 97 To 122, 65 To 90, 48 To 57, 45, 46, 95, 126
          result(i) = Chr(b)
        Case 32
          result(i) = space
        Case 0 To 15
          result(i) = "%0" & Hex(b)
        Case Else
          result(i) = "%" & Hex(b)
      End Select
    Next i

    URLEncode = Join(result, "")
  End If
End Function

This function was found on freevbcode.com:

Public Function URLEncode( _
   StringToEncode As String, _
   Optional UsePlusRatherThanHexForSpace As Boolean = False _
) As String

  Dim TempAns As String
  Dim CurChr As Integer
  CurChr = 1

  Do Until CurChr - 1 = Len(StringToEncode)
    Select Case Asc(Mid(StringToEncode, CurChr, 1))
      Case 48 To 57, 65 To 90, 97 To 122
        TempAns = TempAns & Mid(StringToEncode, CurChr, 1)
      Case 32
        If UsePlusRatherThanHexForSpace = True Then
          TempAns = TempAns & "+"
        Else
          TempAns = TempAns & "%" & Hex(32)
        End If
      Case Else
        TempAns = TempAns & "%" & _
          Right("0" & Hex(Asc(Mid(StringToEncode, _
          CurChr, 1))), 2)
    End Select

    CurChr = CurChr + 1
  Loop

  URLEncode = TempAns
End Function

I've corrected a little bug that was in there.


I would use more efficient (~2× as fast) version of the above:

Public Function URLEncode( _
   StringVal As String, _
   Optional SpaceAsPlus As Boolean = False _
) As String

  Dim StringLen As Long: StringLen = Len(StringVal)

  If StringLen > 0 Then
    ReDim result(StringLen) As String
    Dim i As Long, CharCode As Integer
    Dim Char As String, Space As String

    If SpaceAsPlus Then Space = "+" Else Space = "%20"

    For i = 1 To StringLen
      Char = Mid$(StringVal, i, 1)
      CharCode = Asc(Char)
      Select Case CharCode
        Case 97 To 122, 65 To 90, 48 To 57, 45, 46, 95, 126
          result(i) = Char
        Case 32
          result(i) = Space
        Case 0 To 15
          result(i) = "%0" & Hex(CharCode)
        Case Else
          result(i) = "%" & Hex(CharCode)
      End Select
    Next i
    URLEncode = Join(result, "")
  End If
End Function

Note that neither of these two functions support UTF-8 encoding.

How to get number of rows using SqlDataReader in C#

If you do not need to retrieve all the row and want to avoid to make a double query, you can probably try something like that:

using (var sqlCon = new SqlConnection("Server=127.0.0.1;Database=MyDb;User Id=Me;Password=glop;"))
      {
        sqlCon.Open();

        var com = sqlCon.CreateCommand();
        com.CommandText = "select * from BigTable";
        using (var reader = com.ExecuteReader())
        {
            //here you retrieve what you need
        }

        com.CommandText = "select @@ROWCOUNT";
        var totalRow = com.ExecuteScalar();

        sqlCon.Close();
      }

You may have to add a transaction not sure if reusing the same command will automatically add a transaction on it...

PHP-FPM and Nginx: 502 Bad Gateway

I made all this similar tweaks, but from time to time I was getting 501/502 errors (daily).

This are my settings on /etc/php5/fpm/pool.d/www.conf to avoid 501 and 502 nginx errors… The server has 16Gb RAM. This configuration is for a 8Gb RAM server so…

sudo nano /etc/php5/fpm/pool.d/www.conf

then set the following values for

pm.max_children = 70
pm.start_servers = 20
pm.min_spare_servers = 20
pm.max_spare_servers = 35
pm.max_requests = 500

After this changes restart php-fpm

sudo service php-fpm restart

Display a RecyclerView in Fragment

This was asked some time ago now, but based on the answer that @nacho_zona3 provided, and previous experience with fragments, the issue is that the views have not been created by the time you are trying to find them with the findViewById() method in onCreate() to fix this, move the following code:

// 1. get a reference to recyclerView
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.list);

// 2. set layoutManger
recyclerView.setLayoutManager(new LinearLayoutManager(this));

// this is data fro recycler view
ItemData itemsData[] = { new ItemData("Indigo",R.drawable.circle),
        new ItemData("Red",R.drawable.color_ic_launcher),
        new ItemData("Blue",R.drawable.indigo),
        new ItemData("Green",R.drawable.circle),
        new ItemData("Amber",R.drawable.color_ic_launcher),
        new ItemData("Deep Orange",R.drawable.indigo)};


// 3. create an adapter
MyAdapter mAdapter = new MyAdapter(itemsData);
// 4. set adapter
recyclerView.setAdapter(mAdapter);
// 5. set item animator to DefaultAnimator
recyclerView.setItemAnimator(new DefaultItemAnimator()); 

to your fragment's onCreateView() call. A small amount of refactoring is required because all variables and methods called from this method have to be static. The final code should look like:

 public class ColorsFragment extends Fragment {

     public ColorsFragment() {}

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
         Bundle savedInstanceState) {

         View rootView = inflater.inflate(R.layout.fragment_colors, container, false);
         // 1. get a reference to recyclerView
         RecyclerView recyclerView = (RecyclerView) rootView.findViewById(R.id.list);

         // 2. set layoutManger
         recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

         // this is data fro recycler view
         ItemData itemsData[] = {
             new ItemData("Indigo", R.drawable.circle),
                 new ItemData("Red", R.drawable.color_ic_launcher),
                 new ItemData("Blue", R.drawable.indigo),
                 new ItemData("Green", R.drawable.circle),
                 new ItemData("Amber", R.drawable.color_ic_launcher),
                 new ItemData("Deep Orange", R.drawable.indigo)
         };


         // 3. create an adapter
         MyAdapter mAdapter = new MyAdapter(itemsData);
         // 4. set adapter
         recyclerView.setAdapter(mAdapter);
         // 5. set item animator to DefaultAnimator
         recyclerView.setItemAnimator(new DefaultItemAnimator());

         return rootView;
     }
 }

So the main thing here is that anywhere you call findViewById() you will need to use rootView.findViewById()

How to Set Active Tab in jQuery Ui

just trigger a click, it's work for me:

$("#tabX").trigger("click");

How can I install an older version of a package via NuGet?

Now, it's very much simplified in Visual Studio 2015 and later. You can do downgrade / upgrade within the User interface itself, without executing commands in the Package Manager Console.

  1. Right click on your project and *go to Manage NuGet Packages.

  2. Look at the below image.

    • Select your Package and Choose the Version, which you wanted to install.

NuGet Package Manager window of Project

Very very simple, isn't it? :)

Error while waiting for device: Time out after 300seconds waiting for emulator to come online

I've face this problem, i fixed it by deleting the emulator then created a new one with higher API level.

In my case I've created API-30

What is the best way to insert source code examples into a Microsoft Word document?

I absolutely hate and despise working for free for Microsoft, given how after all those billions of dollars they STILL do not to have proper guides about stuff like this with screenshots on their damn website.

Anyways, here is a quick guide in Word 2010, using Notepad++ for syntax coloring, and a TextBox which can be captioned:

  1. Choose Insert / Text Box / Simple Text Box
    01word
  2. A default text box is inserted
    02word
  3. Switch to NPP, choose the language for syntax coloring of your code, go to Plugins / NPPExport / Copy RTF to clipboard
    03npp
  4. Switch back to word, and paste into the text box - it may be too small ...
    04word
  5. ... so you may have to change its size
    05word
  6. Having selected the text box, right-click on it, then choose Insert Caption ...
    06word
  7. In the Caption menu, if you don't have one already, click New Label, and set the new label to "Code", click OK ...
    07word
  8. ... then in the Caption dialog, switch the label to Code, and hit OK
    08word
  9. Finally, type your caption in the newly created caption box
    09word

Convert file to byte array and vice versa

Apache FileUtil gives very handy methods to do the conversion

try {
    File file = new File(imagefilePath);
    byte[] byteArray = new byte[file.length()]();
    byteArray = FileUtils.readFileToByteArray(file);  
 }catch(Exception e){
     e.printStackTrace();

 }

How can I convert bigint (UNIX timestamp) to datetime in SQL Server?

I had to face this problem, too. Unfortunately, none of the answers (here and in dozens of other pages) has been satisfactory to me, as I still cannot reach dates beyond the year 2038 due to 32 bit integer casts somewhere.

A solution that did work for me in the end was to use float variables, so I could have at least a max date of 2262-04-11T23:47:16.854775849. Still, this doesn't cover the entire datetime domain, but it is sufficient for my needs and may help others encountering the same problem.

-- date variables
declare @ts bigint; -- 64 bit time stamp, 100ns precision
declare @d datetime2(7) = GETUTCDATE(); -- 'now'
-- select @d = '2262-04-11T23:47:16.854775849'; -- this would be the max date

-- constants:
declare @epoch datetime2(7) = cast('1970-01-01T00:00:00' as datetime2(7));
declare @epochdiff int = 25567; -- = days between 1900-01-01 and 1970-01-01
declare @ticksofday bigint = 864000000000; -- = (24*60*60*1000*1000*10)

-- helper variables:
declare @datepart float;
declare @timepart float;
declare @restored datetime2(7);

-- algorithm:
select @ts = DATEDIFF_BIG(NANOSECOND, @epoch, @d) / 100; -- 'now' in ticks according to unix epoch
select @timepart = (@ts % @ticksofday) / @ticksofday; -- extract time part and scale it to fractional part (i. e. 1 hour is 1/24th of a day)
select @datepart = (@ts - @timepart) / @ticksofday; -- extract date part and scale it to fractional part
select @restored = cast(@epochdiff + @datepart + @timepart as datetime); -- rebuild parts to a datetime value

-- query original datetime, intermediate timestamp and restored datetime for comparison
select
  @d original,
  @ts unix64,
  @restored restored
;

-- example result for max date:
-- +-----------------------------+-------------------+-----------------------------+
-- | original                    | unix64            | restored                    |
-- +-----------------------------+-------------------+-----------------------------+
-- | 2262-04-11 23:47:16.8547758 | 92233720368547758 | 2262-04-11 23:47:16.8533333 |
-- +-----------------------------+-------------------+-----------------------------+

There are some points to consider:

  • 100ns precision is the requirement in my case, however this seems to be the standard resolution for 64 bit unix timestamps. If you use any other resolution, you have to adjust @ticksofday and the first line of the algorithm accordingly.
  • I'm using other systems that have their problems with time zones etc. and I found the best solution for me would be always using UTC. For your needs, this may differ.
  • 1900-01-01 is the origin date for datetime2, just as is the epoch 1970-01-01 for unix timestamps.
  • floats helped me to solve the year-2038-problem and integer overflows and such, but keep in mind that floating point numbers are not very performant and may slow down processing of a big amount of timestamps. Also, floats may lead to loss of precision due to roundoff errors, as you can see in the comparison of the example results for the max date above (here, the error is about 1.4425ms).
  • In the last line of the algorithm there is a cast to datetime. Unfortunately, there is no explicit cast from numeric values to datetime2 allowed, but it is allowed to cast numerics to datetime explicitly and this, in turn, is cast implicitly to datetime2. This may be correct, for now, but may change in future versions of SQL Server: Either there will be a dateadd_big() function or the explicit cast to datetime2 will be allowed or the explicit cast to datetime will be disallowed, so this may either break or there may come an easier way some day.

Cannot use a CONTAINS or FREETEXT predicate on table or indexed view because it is not full-text indexed

  1. Make sure you have full-text search feature installed.

    Full-Text Search setup

  2. Create full-text search catalog.

     use AdventureWorks
     create fulltext catalog FullTextCatalog as default
    
     select *
     from sys.fulltext_catalogs
    
  3. Create full-text search index.

     create fulltext index on Production.ProductDescription(Description)
     key index PK_ProductDescription_ProductDescriptionID
    

    Before you create the index, make sure:
    - you don't already have full-text search index on the table as only one full-text search index allowed on a table
    - a unique index exists on the table. The index must be based on single-key column, that does not allow NULL.
    - full-text catalog exists. You have to specify full-text catalog name explicitly if there is no default full-text catalog.

You can do step 2 and 3 in SQL Sever Management Studio. In object explorer, right click on a table, select Full-Text index menu item and then Define Full-Text Index... sub-menu item. Full-Text indexing wizard will guide you through the process. It will also create a full-text search catalog for you if you don't have any yet.

enter image description here

You can find more info at MSDN

How to grep a string in a directory and all its subdirectories?

grep -r -e string directory

-r is for recursive; -e is optional but its argument specifies the regex to search for. Interestingly, POSIX grep is not required to support -r (or -R), but I'm practically certain that System V grep did, so in practice they (almost) all do. Some versions of grep support -R as well as (or conceivably instead of) -r; AFAICT, it means the same thing.

Add space between <li> elements

#access a {
    border-bottom: 2px solid #fff;
    color: #eee;
    display: block;
    line-height: 3.333em;
    padding: 0 10px 0 20px;
    text-decoration: none;
}

I see that you had used line-height but you gave it to <a> tag instead of <ul> Try this:

#access ul {line-height:3.333em;}

You wouldn't need to play with margins then.

Which Android IDE is better - Android Studio or Eclipse?

The use of IDE is your personal preference. But personally if I had to choose, Eclipse is a widely known, trusted and certainly offers more features then Android Studio. Android Studio is a little new right now. May be it's upcoming versions keep up to Eclipse level soon.

WaitAll vs WhenAll

Task.WaitAll blocks the current thread until everything has completed.

Task.WhenAll returns a task which represents the action of waiting until everything has completed.

That means that from an async method, you can use:

await Task.WhenAll(tasks);

... which means your method will continue when everything's completed, but you won't tie up a thread to just hang around until that time.

Determine command line working directory when running node bin script

  • process.cwd() returns directory where command has been executed (not directory of the node package) if it's has not been changed by 'process.chdir' inside of application.
  • __filename returns absolute path to file where it is placed.
  • __dirname returns absolute path to directory of __filename.

If you need to load files from your module directory you need to use relative paths.

require('../lib/test');

instead of

var lib  = path.join(path.dirname(fs.realpathSync(__filename)), '../lib');

require(lib + '/test');

It's always relative to file where it called from and don't depend on current work dir.

Java 8 Streams: multiple filters vs. complex condition

This test shows that your second option can perform significantly better. Findings first, then the code:

one filter with predicate of form u -> exp1 && exp2, list size 10000000, averaged over 100 runs: LongSummaryStatistics{count=100, sum=4142, min=29, average=41.420000, max=82}
two filters with predicates of form u -> exp1, list size 10000000, averaged over 100 runs: LongSummaryStatistics{count=100, sum=13315, min=117, average=133.150000, max=153}
one filter with predicate of form predOne.and(pred2), list size 10000000, averaged over 100 runs: LongSummaryStatistics{count=100, sum=10320, min=82, average=103.200000, max=127}

now the code:

enum Gender {
    FEMALE,
    MALE
}

static class User {
    Gender gender;
    int age;

    public User(Gender gender, int age){
        this.gender = gender;
        this.age = age;
    }

    public Gender getGender() {
        return gender;
    }

    public void setGender(Gender gender) {
        this.gender = gender;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

static long test1(List<User> users){
    long time1 = System.currentTimeMillis();
    users.stream()
            .filter((u) -> u.getGender() == Gender.FEMALE && u.getAge() % 2 == 0)
            .allMatch(u -> true);                   // least overhead terminal function I can think of
    long time2 = System.currentTimeMillis();
    return time2 - time1;
}

static long test2(List<User> users){
    long time1 = System.currentTimeMillis();
    users.stream()
            .filter(u -> u.getGender() == Gender.FEMALE)
            .filter(u -> u.getAge() % 2 == 0)
            .allMatch(u -> true);                   // least overhead terminal function I can think of
    long time2 = System.currentTimeMillis();
    return time2 - time1;
}

static long test3(List<User> users){
    long time1 = System.currentTimeMillis();
    users.stream()
            .filter(((Predicate<User>) u -> u.getGender() == Gender.FEMALE).and(u -> u.getAge() % 2 == 0))
            .allMatch(u -> true);                   // least overhead terminal function I can think of
    long time2 = System.currentTimeMillis();
    return time2 - time1;
}

public static void main(String... args) {
    int size = 10000000;
    List<User> users =
    IntStream.range(0,size)
            .mapToObj(i -> i % 2 == 0 ? new User(Gender.MALE, i % 100) : new User(Gender.FEMALE, i % 100))
            .collect(Collectors.toCollection(()->new ArrayList<>(size)));
    repeat("one filter with predicate of form u -> exp1 && exp2", users, Temp::test1, 100);
    repeat("two filters with predicates of form u -> exp1", users, Temp::test2, 100);
    repeat("one filter with predicate of form predOne.and(pred2)", users, Temp::test3, 100);
}

private static void repeat(String name, List<User> users, ToLongFunction<List<User>> test, int iterations) {
    System.out.println(name + ", list size " + users.size() + ", averaged over " + iterations + " runs: " + IntStream.range(0, iterations)
            .mapToLong(i -> test.applyAsLong(users))
            .summaryStatistics());
}

WCF vs ASP.NET Web API

The new ASP.NET Web API is a continuation of the previous WCF Web API project (although some of the concepts have changed).

WCF was originally created to enable SOAP-based services. For simpler RESTful or RPCish services (think clients like jQuery) ASP.NET Web API should be good choice.


For us, WCF is used for SOAP and Web API for REST. I wish Web API supported SOAP too. We are not using advanced features of WCF. Here is comparison from MSDN:

enter image description here


ASP.net Web API is all about HTTP and REST based GET,POST,PUT,DELETE with well know ASP.net MVC style of programming and JSON returnable; web API is for all the light weight process and pure HTTP based components. For one to go ahead with WCF even for simple or simplest single web service it will bring all the extra baggage. For light weight simple service for ajax or dynamic calls always WebApi just solves the need. This neatly complements or helps in parallel to the ASP.net MVC.

Check out the podcast : Hanselminutes Podcast 264 - This is not your father's WCF - All about the WebAPI with Glenn Block by Scott Hanselman for more information.


In the scenarios listed below you should go for WCF:

  1. If you need to send data on protocols like TCP, MSMQ or MIME
  2. If the consuming client just knows how to consume SOAP messages

WEB API is a framework for developing RESTful/HTTP services.

There are so many clients that do not understand SOAP like Browsers, HTML5, in those cases WEB APIs are a good choice.

HTTP services header specifies how to secure service, how to cache the information, type of the message body and HTTP body can specify any type of content like HTML not just XML as SOAP services.

'JSON' is undefined error in JavaScript in Internet Explorer

I had the very same problem recently. In my case on the top of a php script I had some code generationg obviously some extra output to the browser. Removal of empty lines (between ?> and html-tag ) and simple cleanup helped me out:

<?php 
include('../config.php');

//

ob_clean();
?>
<!DOCTYPE html>

How can I download a specific Maven artifact in one command line?

The usage from the official documentation:

https://maven.apache.org/plugins/maven-dependency-plugin/usage.html#dependency:get

For my case, see the answer below:

mvn dependency:get -Dartifact=$2:$3:$4:$5 -DremoteRepositories=$1 -Dtransitive=false
mvn dependency:copy -Dartifact=$2:$3:$4:$5 -DremoteRepositories=$1 -Dtransitive=false -DoutputDirectory=$6

#mvn dependency:get -Dartifact=com.huya.mtp:hynswup:1.0.88-SNAPSHOT:jar -DremoteRepositories=http://nexus.google.com:8081/repository/maven-snapshots/ -Dtransitive=false
#mvn dependency:copy -Dartifact=com.huya.mtp:hynswup:1.0.88-SNAPSHOT:jar -DremoteRepositories=http://nexus.google.com:8081/repository/maven-snapshots/ -Dtransitive=false -DoutputDirectory=.

Use the command mvn dependency:get to download the specific artifact and use the command mvn dependency:copy to copy the downloaded artifact to the destination directory -DoutputDirectory.

How to fix "Incorrect string value" errors?

To fix this error I upgraded my MySQL database to utf8mb4 which supports the full Unicode character set by following this detailed tutorial. I suggest going through it carefully, because there are quite a few gotchas (e.g. the index keys can become too large due to the new encodings after which you have to modify field types).

How to get the entire document HTML as a string?

MS added the outerHTML and innerHTML properties some time ago.

According to MDN, outerHTML is supported in Firefox 11, Chrome 0.2, Internet Explorer 4.0, Opera 7, Safari 1.3, Android, Firefox Mobile 11, IE Mobile, Opera Mobile, and Safari Mobile. outerHTML is in the DOM Parsing and Serialization specification.

See quirksmode for browser compatibility for what will work for you. All support innerHTML.

var markup = document.documentElement.innerHTML;
alert(markup);

Excel - Using COUNTIF/COUNTIFS across multiple sheets/same column

I am trying to avoid using VBA. But if has to be, then it has to be:)

There is quite simple UDF for you:

Function myCountIf(rng As Range, criteria) As Long
    Dim ws As Worksheet

    For Each ws In ThisWorkbook.Worksheets
        myCountIf = myCountIf + WorksheetFunction.CountIf(ws.Range(rng.Address), criteria)
    Next ws
End Function

and call it like this: =myCountIf(I:I,A13)


P.S. if you'd like to exclude some sheets, you can add If statement:

Function myCountIf(rng As Range, criteria) As Long
    Dim ws As Worksheet

    For Each ws In ThisWorkbook.Worksheets
        If ws.name <> "Sheet1" And ws.name <> "Sheet2" Then
            myCountIf = myCountIf + WorksheetFunction.CountIf(ws.Range(rng.Address), criteria)
        End If
    Next ws
End Function

UPD:

I have four "reference" sheets that I need to exclude from being scanned/searched. They are currently the last four in the workbook

Function myCountIf(rng As Range, criteria) As Long
    Dim i As Integer

    For i = 1 To ThisWorkbook.Worksheets.Count - 4
        myCountIf = myCountIf + WorksheetFunction.CountIf(ThisWorkbook.Worksheets(i).Range(rng.Address), criteria)
    Next i
End Function

How do I add a tool tip to a span element?

In most browsers, the title attribute will render as a tooltip, and is generally flexible as to what sorts of elements it'll work with.

<span title="This will show as a tooltip">Mouse over for a tooltip!</span>
<a href="http://www.stackoverflow.com" title="Link to stackoverflow.com">stackoverflow.com</a>
<img src="something.png" alt="Something" title="Something">

All of those will render tooltips in most every browser.

How to calculate rolling / moving average using NumPy / SciPy?

By comparing the solution below with the one that uses cumsum of numpy, This one takes almost half the time. This is because it does not need to go through the entire array to do the cumsum and then do all the subtraction. Moreover, the cumsum can be "dangerous" if the array is huge and the number are huge (possible overflow). Of course, also here the danger exists but at least are summed together only the essential numbers.

def moving_average(array_numbers, n):
    if n > len(array_numbers):
      return []
    temp_sum = sum(array_numbers[:n])
    averages = [temp_sum / float(n)]
    for first_index, item in enumerate(array_numbers[n:]):
        temp_sum += item - array_numbers[first_index]
        averages.append(temp_sum / float(n))
    return averages

Error: Cannot find module 'ejs'

Way back when the same issue happened with me.

Dependency was there for ejs in JSON file, tried installing it locally and globally but did not work.

Then what I did was manually adding the module by:

app.set('view engine','ejs'); 

app.engine('ejs', require('ejs').__express);

Then it works.

Sending event when AngularJS finished loading

I had a fragment that was getting loaded-in after/by the main partial that came in via routing.

I needed to run a function after that subpartial loaded and I didn't want to write a new directive and figured out you could use a cheeky ngIf

Controller of parent partial:

$scope.subIsLoaded = function() { /*do stuff*/; return true; };

HTML of subpartial

<element ng-if="subIsLoaded()"><!-- more html --></element>

How To Include CSS and jQuery in my WordPress plugin?

See http://codex.wordpress.org/Function_Reference/wp_enqueue_script

Example

<?php
function my_init_method() {
    wp_deregister_script( 'jquery' );
    wp_register_script( 'jquery', 'http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js');
}    

add_action('init', 'my_init_method');
?> 

Is there a way to retrieve the view definition from a SQL Server using plain ADO?

Which version of SQL Server?

For SQL Server 2005 and later, you can obtain the SQL script used to create the view like this:

select definition
from sys.objects     o
join sys.sql_modules m on m.object_id = o.object_id
where o.object_id = object_id( 'dbo.MyView')
  and o.type      = 'V'

This returns a single row containing the script used to create/alter the view.

Other columns in the table tell about about options in place at the time the view was compiled.

Caveats

  • If the view was last modified with ALTER VIEW, then the script will be an ALTER VIEW statement rather than a CREATE VIEW statement.

  • The script reflects the name as it was created. The only time it gets updated is if you execute ALTER VIEW, or drop and recreate the view with CREATE VIEW. If the view has been renamed (e.g., via sp_rename) or ownership has been transferred to a different schema, the script you get back will reflect the original CREATE/ALTER VIEW statement: it will not reflect the objects current name.

  • Some tools truncate the output. For example, the MS-SQL command line tool sqlcmd.exe truncates the data at 255 chars. You can pass the parameter -y N to get the result with N chars.

Java regex email

you can use a simple regular expression for validating email id,

public boolean validateEmail(String email){
  return Pattern.matches("[_a-zA-Z1-9]+(\\.[A-Za-z0-9]*)*@[A-Za-z0-9]+\\.[A-Za-z0-9]+(\\.[A-Za-z0-9]*)*", email)
}

Description :

  1. [_a-zA-Z1-9]+ - it will accept all A-Z,a-z, 0-9 and _ (+ mean it must be occur)
  2. (\.[A-Za-z0-9]) - it's optional which will accept . and A-Z, a-z, 0-9( * mean its optional)
  3. @[A-Za-z0-9]+ - it wil accept @ and A-Z,a-z,0-9
  4. \.[A-Za-z0-9]+ - its for . and A-Z,a-z,0-9
  5. (\.[A-Za-z0-9]) - it occur, . but its optional

Causes of getting a java.lang.VerifyError

I have fixed a similar java.lang.VerifyError issue by replacing

        catch (MagickException e)

with

        catch (Exception e)

where MagickException was defined in a library project (on which my project has a dependency).

After that I have got a java.lang.NoClassDefFoundError about a class from the same library (fixed according to https://stackoverflow.com/a/9898820/755804 ).

Convert JSON String to JSON Object c#

If your JSon string has "" double quote instead of a single quote ' and has \n as a indicator of a next line then you need to remove it because that's not a proper JSon string, example as shown below:

            SomeClass dna = new SomeClass ();
            string response = wc.DownloadString(url);
            string strRemSlash = response.Replace("\"", "\'");
            string strRemNline = strRemSlash.Replace("\n", " ");
            // Time to desrialize it to convert it into an object class.
            dna = JsonConvert.DeserializeObject<SomeClass>(@strRemNline);

Grouping functions (tapply, by, aggregate) and the *apply family

I recently discovered the rather useful sweep function and add it here for the sake of completeness:

sweep

The basic idea is to sweep through an array row- or column-wise and return a modified array. An example will make this clear (source: datacamp):

Let's say you have a matrix and want to standardize it column-wise:

dataPoints <- matrix(4:15, nrow = 4)

# Find means per column with `apply()`
dataPoints_means <- apply(dataPoints, 2, mean)

# Find standard deviation with `apply()`
dataPoints_sdev <- apply(dataPoints, 2, sd)

# Center the points 
dataPoints_Trans1 <- sweep(dataPoints, 2, dataPoints_means,"-")

# Return the result
dataPoints_Trans1
##      [,1] [,2] [,3]
## [1,] -1.5 -1.5 -1.5
## [2,] -0.5 -0.5 -0.5
## [3,]  0.5  0.5  0.5
## [4,]  1.5  1.5  1.5

# Normalize
dataPoints_Trans2 <- sweep(dataPoints_Trans1, 2, dataPoints_sdev, "/")

# Return the result
dataPoints_Trans2
##            [,1]       [,2]       [,3]
## [1,] -1.1618950 -1.1618950 -1.1618950
## [2,] -0.3872983 -0.3872983 -0.3872983
## [3,]  0.3872983  0.3872983  0.3872983
## [4,]  1.1618950  1.1618950  1.1618950

NB: for this simple example the same result can of course be achieved more easily by
apply(dataPoints, 2, scale)

How to count TRUE values in a logical vector

I've just had a particular problem where I had to count the number of true statements from a logical vector and this worked best for me...

length(grep(TRUE, (gene.rep.matrix[i,1:6] > 1))) > 5

So This takes a subset of the gene.rep.matrix object, and applies a logical test, returning a logical vector. This vector is put as an argument to grep, which returns the locations of any TRUE entries. Length then calculates how many entries grep finds, thus giving the number of TRUE entries.

Python error when trying to access list by index - "List indices must be integers, not str"

A list is a chain of spaces that can be indexed by (0, 1, 2 .... etc). So if players was a list, players[0] or players[1] would have worked. If players is a dictionary, players["name"] would have worked.

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory in ionic 3

For some reasons all the answer above didn't really work for me, I did the following to fix my issue:

  1. I had to first delete the node_modules folder
  2. re-install node.js on my PC and
  3. then npm install

Converting Array to List

If you don't mind a third-party dependency, you could use a library which natively supports primitive collections like Eclipse Collections and avoid the boxing altogether. You can also use primitive collections to create boxed regular collections if you need to.

int[] ints = {1, 2, 3};
MutableIntList intList = IntLists.mutable.with(ints);
List<Integer> list = intList.collect(Integer::valueOf);

If you want the boxed collection in the end, this is what the code for collect on IntArrayList is doing under the covers:

public <V> MutableList<V> collect(IntToObjectFunction<? extends V> function)
{
    return this.collect(function, FastList.newList(this.size));
}

public <V, R extends Collection<V>> R collect(IntToObjectFunction<? extends V> function, 
                                              R target)
{
    for (int i = 0; i < this.size; i++)
    {
        target.add(function.valueOf(this.items[i]));
    }
    return target;
}

Since the question was specifically about performance, I wrote some JMH benchmarks using your solutions, the most voted answer and the primitive and boxed versions of Eclipse Collections.

import org.eclipse.collections.api.list.primitive.IntList;
import org.eclipse.collections.impl.factory.primitive.IntLists;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.RunnerException;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

@State(Scope.Thread)
@BenchmarkMode(Mode.Throughput)
@OutputTimeUnit(TimeUnit.SECONDS)
@Fork(2)
public class IntegerArrayListFromIntArray
{
    private int[] source = IntStream.range(0, 1000).toArray();

    public static void main(String[] args) throws RunnerException
    {
        Options options = new OptionsBuilder().include(
                ".*" + IntegerArrayListFromIntArray.class.getSimpleName() + ".*")
                .forks(2)
                .mode(Mode.Throughput)
                .timeUnit(TimeUnit.SECONDS)
                .build();
        new Runner(options).run();
    }

    @Benchmark
    public List<Integer> jdkClassic()
    {
        List<Integer> list = new ArrayList<>(source.length);
        for (int each : source)
        {
            list.add(each);
        }
        return list;
    }

    @Benchmark
    public List<Integer> jdkStreams1()
    {
        List<Integer> list = new ArrayList<>(source.length);
        Collections.addAll(list,
                Arrays.stream(source).boxed().toArray(Integer[]::new));
        return list;
    }

    @Benchmark
    public List<Integer> jdkStreams2()
    {
        return Arrays.stream(source).boxed().collect(Collectors.toList());
    }

    @Benchmark
    public IntList ecPrimitive()
    {
        return IntLists.immutable.with(source);
    }

    @Benchmark
    public List<Integer> ecBoxed()
    {
        return IntLists.mutable.with(source).collect(Integer::valueOf);
    }
}

These are the results from these tests on my Mac Book Pro. The units are operations per second, so the bigger the number, the better. I used an ImmutableIntList for the ecPrimitive benchmark, because the MutableIntList in Eclipse Collections doesn't copy the array by default. It merely adapts the array you give it. This was reporting even larger numbers for ecPrimitive, with a very large margin of error because it was essentially measuring the cost of a single object creation.

# Run complete. Total time: 00:06:52

Benchmark                                  Mode  Cnt        Score      Error  Units
IntegerArrayListFromIntArray.ecBoxed      thrpt   40   191671.859 ± 2107.723  ops/s
IntegerArrayListFromIntArray.ecPrimitive  thrpt   40  2311575.358 ± 9194.262  ops/s
IntegerArrayListFromIntArray.jdkClassic   thrpt   40   138231.703 ± 1817.613  ops/s
IntegerArrayListFromIntArray.jdkStreams1  thrpt   40    87421.892 ± 1425.735  ops/s
IntegerArrayListFromIntArray.jdkStreams2  thrpt   40   103034.520 ± 1669.947  ops/s

If anyone spots any issues with the benchmarks, I'll be happy to make corrections and run them again.

Note: I am a committer for Eclipse Collections.

Pass a local file in to URL in Java

new URL("file:///your/file/here")

What is the fastest way to compare two sets in Java?

I would put the secondSet in a HashMap before the comparison. This way you will reduce the second list's search time to n(1). Like this:

HashMap<Integer,Record> hm = new HashMap<Integer,Record>(secondSet.size());
int i = 0;
for(Record secondRecord : secondSet){
    hm.put(i,secondRecord);
    i++;
}
for(Record firstRecord : firstSet){
    for(int i=0; i<secondSet.size(); i++){
    //use hm for comparison
    }
}

how to use JSON.stringify and json_decode() properly

You'll need to check the contents of $_POST["JSONfullInfoArray"]. If something doesn't parse json_decode will just return null. This isn't very helpful so when null is returned you should check json_last_error() to get more info on what went wrong.

Join two data frames, select all columns from one and some columns from the other

Without using alias.

df1.join(df2, df1.id == df2.id).select(df1["*"],df2["other"])

Reading a file character by character in C

the file is being opened and not closed for each call to the function also

GCC -fPIC option

I'll try to explain what has already been said in a simpler way.

Whenever a shared lib is loaded, the loader (the code on the OS which load any program you run) changes some addresses in the code depending on where the object was loaded to.

In the above example, the "111" in the non-PIC code is written by the loader the first time it was loaded.

For not shared objects, you may want it to be like that because the compiler can make some optimizations on that code.

For shared object, if another process will want to "link" to that code he must read it to the same virtual addresses or the "111" will make no sense. but that virtual-space may already be in use in the second process.

Bold & Non-Bold Text In A Single UILabel?

Update

In Swift we don't have to deal with iOS5 old stuff besides syntax is shorter so everything becomes really simple:

Swift 5

func attributedString(from string: String, nonBoldRange: NSRange?) -> NSAttributedString {
    let fontSize = UIFont.systemFontSize
    let attrs = [
        NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: fontSize),
        NSAttributedString.Key.foregroundColor: UIColor.black
    ]
    let nonBoldAttribute = [
        NSAttributedString.Key.font: UIFont.systemFont(ofSize: fontSize),
    ]
    let attrStr = NSMutableAttributedString(string: string, attributes: attrs)
    if let range = nonBoldRange {
        attrStr.setAttributes(nonBoldAttribute, range: range)
    }
    return attrStr
}

Swift 3

func attributedString(from string: String, nonBoldRange: NSRange?) -> NSAttributedString {
    let fontSize = UIFont.systemFontSize
    let attrs = [
        NSFontAttributeName: UIFont.boldSystemFont(ofSize: fontSize),
        NSForegroundColorAttributeName: UIColor.black
    ]
    let nonBoldAttribute = [
        NSFontAttributeName: UIFont.systemFont(ofSize: fontSize),
    ]
    let attrStr = NSMutableAttributedString(string: string, attributes: attrs)
    if let range = nonBoldRange {
        attrStr.setAttributes(nonBoldAttribute, range: range)
    }
    return attrStr
}

Usage:

let targetString = "Updated 2012/10/14 21:59 PM"
let range = NSMakeRange(7, 12)

let label = UILabel(frame: CGRect(x:0, y:0, width:350, height:44))
label.backgroundColor = UIColor.white
label.attributedText = attributedString(from: targetString, nonBoldRange: range)
label.sizeToFit()

Bonus: Internationalisation

Some people commented about internationalisation. I personally think this is out of scope of this question but for instructional purposes this is how I would do it

// Date we want to show
let date = Date()

// Create the string.
// I don't set the locale because the default locale of the formatter is `NSLocale.current` so it's good for internationalisation :p
let formatter = DateFormatter()
formatter.dateStyle = .medium
formatter.timeStyle = .short
let targetString = String(format: NSLocalizedString("Update %@", comment: "Updated string format"),
                          formatter.string(from: date))

// Find the range of the non-bold part
formatter.timeStyle = .none
let nonBoldRange = targetString.range(of: formatter.string(from: date))

// Convert Range<Int> into NSRange
let nonBoldNSRange: NSRange? = nonBoldRange == nil ?
    nil :
    NSMakeRange(targetString.distance(from: targetString.startIndex, to: nonBoldRange!.lowerBound),
                targetString.distance(from: nonBoldRange!.lowerBound, to: nonBoldRange!.upperBound))

// Now just build the attributed string as before :)
label.attributedText = attributedString(from: targetString,
                                        nonBoldRange: nonBoldNSRange)

Result (Assuming English and Japanese Localizable.strings are available)

enter image description here

enter image description here


Previous answer for iOS6 and later (Objective-C still works):

In iOS6 UILabel, UIButton, UITextView, UITextField, support attributed strings which means we don't need to create CATextLayers as our recipient for attributed strings. Furthermore to make the attributed string we don't need to play with CoreText anymore :) We have new classes in obj-c Foundation.framework like NSParagraphStyle and other constants that will make our life easier. Yay!

So, if we have this string:

NSString *text = @"Updated: 2012/10/14 21:59"

We only need to create the attributed string:

if ([_label respondsToSelector:@selector(setAttributedText:)])
{
    // iOS6 and above : Use NSAttributedStrings

    // Create the attributes
    const CGFloat fontSize = 13;
    NSDictionary *attrs = @{
        NSFontAttributeName:[UIFont boldSystemFontOfSize:fontSize],
        NSForegroundColorAttributeName:[UIColor whiteColor]
    };
    NSDictionary *subAttrs = @{
        NSFontAttributeName:[UIFont systemFontOfSize:fontSize]
    };

    // Range of " 2012/10/14 " is (8,12). Ideally it shouldn't be hardcoded
    // This example is about attributed strings in one label
    // not about internationalisation, so we keep it simple :)
    // For internationalisation example see above code in swift
    const NSRange range = NSMakeRange(8,12);

    // Create the attributed string (text + attributes)
    NSMutableAttributedString *attributedText =
      [[NSMutableAttributedString alloc] initWithString:text
                                             attributes:attrs];
    [attributedText setAttributes:subAttrs range:range];

    // Set it in our UILabel and we are done!
    [_label setAttributedText:attributedText];
} else {
    // iOS5 and below
    // Here we have some options too. The first one is to do something
    // less fancy and show it just as plain text without attributes.
    // The second is to use CoreText and get similar results with a bit
    // more of code. Interested people please look down the old answer.

    // Now I am just being lazy so :p
    [_label setText:text];
}

There is a couple of good introductory blog posts here from guys at invasivecode that explain with more examples uses of NSAttributedString, look for "Introduction to NSAttributedString for iOS 6" and "Attributed strings for iOS using Interface Builder" :)

PS: Above code it should work but it was brain-compiled. I hope it is enough :)


Old Answer for iOS5 and below

Use a CATextLayer with an NSAttributedString ! much lighter and simpler than 2 UILabels. (iOS 3.2 and above)

Example.

Don't forget to add QuartzCore framework (needed for CALayers), and CoreText (needed for the attributed string.)

#import <QuartzCore/QuartzCore.h>
#import <CoreText/CoreText.h>

Below example will add a sublayer to the toolbar of the navigation controller. à la Mail.app in the iPhone. :)

- (void)setRefreshDate:(NSDate *)aDate
{
    [aDate retain];
    [refreshDate release];
    refreshDate = aDate;

    if (refreshDate) {

        /* Create the text for the text layer*/    
        NSDateFormatter *df = [[NSDateFormatter alloc] init];
        [df setDateFormat:@"MM/dd/yyyy hh:mm"];

        NSString *dateString = [df stringFromDate:refreshDate];
        NSString *prefix = NSLocalizedString(@"Updated", nil);
        NSString *text = [NSString stringWithFormat:@"%@: %@",prefix, dateString];
        [df release];

        /* Create the text layer on demand */
        if (!_textLayer) {
            _textLayer = [[CATextLayer alloc] init];
            //_textLayer.font = [UIFont boldSystemFontOfSize:13].fontName; // not needed since `string` property will be an NSAttributedString
            _textLayer.backgroundColor = [UIColor clearColor].CGColor;
            _textLayer.wrapped = NO;
            CALayer *layer = self.navigationController.toolbar.layer; //self is a view controller contained by a navigation controller
            _textLayer.frame = CGRectMake((layer.bounds.size.width-180)/2 + 10, (layer.bounds.size.height-30)/2 + 10, 180, 30);
            _textLayer.contentsScale = [[UIScreen mainScreen] scale]; // looks nice in retina displays too :)
            _textLayer.alignmentMode = kCAAlignmentCenter;
            [layer addSublayer:_textLayer];
        }

        /* Create the attributes (for the attributed string) */
        CGFloat fontSize = 13;
        UIFont *boldFont = [UIFont boldSystemFontOfSize:fontSize];
        CTFontRef ctBoldFont = CTFontCreateWithName((CFStringRef)boldFont.fontName, boldFont.pointSize, NULL);
        UIFont *font = [UIFont systemFontOfSize:13];
        CTFontRef ctFont = CTFontCreateWithName((CFStringRef)font.fontName, font.pointSize, NULL);
        CGColorRef cgColor = [UIColor whiteColor].CGColor;
        NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys:
                                    (id)ctBoldFont, (id)kCTFontAttributeName,
                                    cgColor, (id)kCTForegroundColorAttributeName, nil];
        CFRelease(ctBoldFont);
        NSDictionary *subAttributes = [NSDictionary dictionaryWithObjectsAndKeys:(id)ctFont, (id)kCTFontAttributeName, nil];
        CFRelease(ctFont);

        /* Create the attributed string (text + attributes) */
        NSMutableAttributedString *attrStr = [[NSMutableAttributedString alloc] initWithString:text attributes:attributes];
        [attrStr addAttributes:subAttributes range:NSMakeRange(prefix.length, 12)]; //12 is the length of " MM/dd/yyyy/ "

        /* Set the attributes string in the text layer :) */
        _textLayer.string = attrStr;
        [attrStr release];

        _textLayer.opacity = 1.0;
    } else {
        _textLayer.opacity = 0.0;
        _textLayer.string = nil;
    }
}

In this example I only have two different types of font (bold and normal) but you could also have different font size, different color, italics, underlined, etc. Take a look at NSAttributedString / NSMutableAttributedString and CoreText attributes string keys.

Hope it helps

What does "javascript:void(0)" mean?

The void operator evaluates the given expression and then returns undefined. It avoids refreshing the page.

What's the difference between __PRETTY_FUNCTION__, __FUNCTION__, __func__?

__PRETTY_FUNCTION__ handles C++ features: classes, namespaces, templates and overload

main.cpp

#include <iostream>

namespace N {
    class C {
        public:
            template <class T>
            static void f(int i) {
                (void)i;
                std::cout << "__func__            " << __func__ << std::endl
                          << "__FUNCTION__        " << __FUNCTION__ << std::endl
                          << "__PRETTY_FUNCTION__ " << __PRETTY_FUNCTION__ << std::endl;
            }
            template <class T>
            static void f(double f) {
                (void)f;
                std::cout << "__PRETTY_FUNCTION__ " << __PRETTY_FUNCTION__ << std::endl;
            }
    };
}

int main() {
    N::C::f<char>(1);
    N::C::f<void>(1.0);
}

Compile and run:

g++ -ggdb3 -O0 -std=c++11 -Wall -Wextra -pedantic -o main.out main.cpp
./main.out

Output:

__func__            f
__FUNCTION__        f
__PRETTY_FUNCTION__ static void N::C::f(int) [with T = char]
__PRETTY_FUNCTION__ static void N::C::f(double) [with T = void]

You may also be interested in stack traces with function names: print call stack in C or C++

Tested in Ubuntu 19.04, GCC 8.3.0.

C++20 std::source_location::function_name

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1208r5.pdf went into C++20, so we have yet another way to do it.

The documentation says:

constexpr const char* function_name() const noexcept;

6 Returns: If this object represents a position in the body of a function, returns an implementation-defined NTBS that should correspond to the function name. Otherwise, returns an empty string.

where NTBS means "Null Terminated Byte String".

I'll give it a try when support arrives to GCC, GCC 9.1.0 with g++-9 -std=c++2a still doesn't support it.

https://en.cppreference.com/w/cpp/utility/source_location claims usage will be like:

#include <iostream>
#include <string_view>
#include <source_location>
 
void log(std::string_view message,
         const std::source_location& location std::source_location::current()
) {
    std::cout << "info:"
              << location.file_name() << ":"
              << location.line() << ":"
              << location.function_name() << " "
              << message << '\n';
}
 
int main() {
    log("Hello world!");
}

Possible output:

info:main.cpp:16:main Hello world!

so note how this returns the caller information, and is therefore perfect for usage in logging, see also: Is there a way to get function name inside a C++ function?

Calculate distance in meters when you know longitude and latitude in java

You can use the Java Geodesy Library for GPS, it uses the Vincenty's formulae which takes account of the earths surface curvature.

Implementation goes like this:

import org.gavaghan.geodesy.*;

...

GeodeticCalculator geoCalc = new GeodeticCalculator();

Ellipsoid reference = Ellipsoid.WGS84;  

GlobalPosition pointA = new GlobalPosition(latitude, longitude, 0.0); // Point A

GlobalPosition userPos = new GlobalPosition(userLat, userLon, 0.0); // Point B

double distance = geoCalc.calculateGeodeticCurve(reference, userPos, pointA).getEllipsoidalDistance(); // Distance between Point A and Point B

The resulting distance is in meters.

C++ Object Instantiation

There's no reason to new (on the heap) when you can allocate on the stack (unless for some reason you've got a small stack and want to use the heap.

You might want to consider using a shared_ptr (or one of its variants) from the standard library if you do want to allocate on the heap. That'll handle doing the delete for you once all references to the shared_ptr have gone out of existance.

How do I implement interfaces in python?

Something like this (might not work as I don't have Python around):

class IInterface:
    def show(self): raise NotImplementedError

class MyClass(IInterface):
    def show(self): print "Hello World!"

Get file version in PowerShell

This is based on the other answers, but is exactly what I was after:

(Get-Command C:\Path\YourFile.Dll).FileVersionInfo.FileVersion

Algorithm: efficient way to remove duplicate integers from an array

The return value of the function should be the number of unique elements and they are all stored at the front of the array. Without this additional information, you won't even know if there were any duplicates.

Each iteration of the outer loop processes one element of the array. If it is unique, it stays in the front of the array and if it is a duplicate, it is overwritten by the last unprocessed element in the array. This solution runs in O(n^2) time.

#include <stdio.h>
#include <stdlib.h>

size_t rmdup(int *arr, size_t len)
{
  size_t prev = 0;
  size_t curr = 1;
  size_t last = len - 1;
  while (curr <= last) {
    for (prev = 0; prev < curr && arr[curr] != arr[prev]; ++prev);
    if (prev == curr) {
      ++curr;
    } else {
      arr[curr] = arr[last];
      --last;
    }
  }
  return curr;
}

void print_array(int *arr, size_t len)
{
  printf("{");
  size_t curr = 0;
  for (curr = 0; curr < len; ++curr) {
    if (curr > 0) printf(", ");
    printf("%d", arr[curr]);
  }
  printf("}");
}

int main()
{
  int arr[] = {4, 8, 4, 1, 1, 2, 9};
  printf("Before: ");
  size_t len = sizeof (arr) / sizeof (arr[0]);
  print_array(arr, len);
  len = rmdup(arr, len);
  printf("\nAfter: ");
  print_array(arr, len);
  printf("\n");
  return 0;
}

IndentationError: unexpected unindent WHY?

It's because you have:

def readTTable(fname):
    try:

without a matching except block after the try: block. Every try must have at least one matching except.

See the Errors and Exceptions section of the Python tutorial.

How to use OKHTTP to make a post request?

private final OkHttpClient client = new OkHttpClient();

  public void run() throws Exception {
    RequestBody formBody = new FormEncodingBuilder()
        .add("search", "Jurassic Park")
        .build();
    Request request = new Request.Builder()
        .url("https://en.wikipedia.org/w/index.php")
        .post(formBody)
        .build();

    Response response = client.newCall(request).execute();
    if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

    System.out.println(response.body().string());
  }

Sending HTML email using Python

Here is a Gmail implementation of the accepted answer:

import smtplib

from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

# me == my email address
# you == recipient's email address
me = "[email protected]"
you = "[email protected]"

# Create message container - the correct MIME type is multipart/alternative.
msg = MIMEMultipart('alternative')
msg['Subject'] = "Link"
msg['From'] = me
msg['To'] = you

# Create the body of the message (a plain-text and an HTML version).
text = "Hi!\nHow are you?\nHere is the link you wanted:\nhttp://www.python.org"
html = """\
<html>
  <head></head>
  <body>
    <p>Hi!<br>
       How are you?<br>
       Here is the <a href="http://www.python.org">link</a> you wanted.
    </p>
  </body>
</html>
"""

# Record the MIME types of both parts - text/plain and text/html.
part1 = MIMEText(text, 'plain')
part2 = MIMEText(html, 'html')

# Attach parts into message container.
# According to RFC 2046, the last part of a multipart message, in this case
# the HTML message, is best and preferred.
msg.attach(part1)
msg.attach(part2)
# Send the message via local SMTP server.
mail = smtplib.SMTP('smtp.gmail.com', 587)

mail.ehlo()

mail.starttls()

mail.login('userName', 'password')
mail.sendmail(me, you, msg.as_string())
mail.quit()

How can I undo a mysql statement that I just executed?

You can stop a query which is being processed by this

Find the Id of the query process by => show processlist;

Then => kill id;

Pentaho Data Integration SQL connection

In addition to the other answers here, here's how you can do it on Ubuntu (14.04):

sudo apt-get install libmysql-java

this will download mysql-connector-java-5.x.x.jar to /usr/share/java/, which i believe also automatically creates a symlink named mysql-connector-java.jar.

Then, create a symlink in /your/path/to/data-integration/lib/:

ln -s /usr/share/java/mysql-connector-java.jar /your/path/to/data-integration/lib/mysql-connector-java.jar

How do I measure request and response times at once using cURL?

Option 1. To measure total time:

curl -o /dev/null -s -w 'Total: %{time_total}s\n'  https://www.google.com

Sample output:

enter image description here

Option 2. To get time to establish connection, TTFB: time to first byte and total time:

curl -o /dev/null -s -w 'Establish Connection: %{time_connect}s\nTTFB: %{time_starttransfer}s\nTotal: %{time_total}s\n'  https://www.google.com

Sample output:

enter image description here

Ref: Get response time with curl

password-check directive in angularjs

Not a directive solution but is working for me:

<input ng-model='user.password'
 type="password"
 name='password'
 placeholder='password'
 required>
<input ng-model='user.password_verify'
 type="password" 
 name='confirm_password'
 placeholder='confirm password'
 ng-pattern="getPattern()"
 required>

And in the controller:

//Escape the special chars
    $scope.getPattern = function(){
        return $scope.user.password && 
              $scope.user.password.replace(/([.*+?^${}()|\[\]\/\\])/g, '\\$1');
    }

http://plnkr.co/edit/QDTnipCsHdg56vgygsqC?p=preview

jQuery .val() vs .attr("value")

PS: This is not an answer but just a supplement to the above answers.

Just for the future reference, I have included a good example that might help us to clear our doubt:

Try the following. In this example I shall create a file selector which can be used to select a file and then I shall try to retrieve the name of the file that I selected: The HTML code is below:

<html>
    <body>
        <form action="#" method="post">
            <input id ="myfile" type="file"/>
        </form>
        <script type="text/javascript" src="jquery.js"> </script>
        <script type="text/javascript" src="code.js"> </script>
    </body>
</html>

The code.js file contains the following jQuery code. Try to use both of the jQuery code snippets one by one and see the output.

jQuery code with attr('value'):

$('#myfile').change(function(){
    alert($(this).attr('value'));
    $('#mybutton').removeAttr('disabled');
});

jQuery code with val():

$('#myfile').change(function(){
    alert($(this).val());
    $('#mybutton').removeAttr('disabled');
});

Output:

The output of jQuery code with attr('value') will be 'undefined'. The output of jQuery code with val() will the file name that you selected.

Explanation: Now you may understand easily what the top answers wanted to convey. The output of jQuery code with attr('value') will be 'undefined' because initially there was no file selected so the value is undefined. It is better to use val() because it gets the current value.

In order to see why the undefined value is returned try this code in your HTML and you'll see that now the attr.('value') returns 'test' always, because the value is 'test' and previously it was undefined.

<input id ="myfile" type="file" value='test'/>

I hope it was useful to you.

How to check if a String is numeric in Java

Java 8 lambda expressions.

String someString = "123123";
boolean isNumeric = someString.chars().allMatch( Character::isDigit );

How to remove commits from a pull request

This is what helped me:

  1. Create a new branch with the existing one. Let's call the existing one branch_old and new as branch_new.

  2. Reset branch_new to a stable state, when you did not have any problem commit at all. For example, to put it at your local master's level do the following:

    git reset —hard master git push —force origin

  3. cherry-pick the commits from branch_old into branch_new

  4. git push

C++ auto keyword. Why is it magic?

The auto keyword is an important and frequently used keyword for C ++.When initializing a variable, auto keyword is used for type inference(also called type deduction).

There are 3 different rules regarding the auto keyword.

First Rule

auto x = expr; ----> No pointer or reference, only variable name. In this case, const and reference are ignored.

int  y = 10;
int& r = y;
auto x = r; // The type of variable x is int. (Reference Ignored)

const int y = 10;
auto x = y; // The type of variable x is int. (Const Ignored)

int y = 10;
const int& r = y;
auto x = r; // The type of variable x is int. (Both const and reference Ignored)

const int a[10] = {};
auto x = a; //  x is const int *. (Array to pointer conversion)

Note : When the name defined by auto is given a value with the name of a function,
       the type inference will be done as a function pointer.

Second Rule

auto& y = expr; or auto* y = expr; ----> Reference or pointer after auto keyword.

Warning : const is not ignored in this rule !!! .

int y = 10;
auto& x = y; // The type of variable x is int&.

Warning : In this rule, array to pointer conversion (array decay) does not occur !!!.

auto& x = "hello"; // The type of variable x is  const char [6].

static int x = 10;
auto y = x; // The variable y is not static.Because the static keyword is not a type. specifier 
            // The type of variable x is int.

Third Rule

auto&& z = expr; ----> This is not a Rvalue reference.

Warning : If the type inference is in question and the && token is used, the names introduced like this are called "Forwarding Reference" (also called Universal Reference).

auto&& r1 = x; // The type of variable r1 is int&.Because x is Lvalue expression. 

auto&& r2 = x+y; // The type of variable r2 is int&&.Because x+y is PRvalue expression. 

How to filter specific apps for ACTION_SEND intent (and set a different text for each app)

So simple and concise. Thanks to the Open source developer, cketti for sharing this solution:

String mailto = "mailto:[email protected]" +
    "?cc=" + "[email protected]" +
    "&subject=" + Uri.encode(subject) +
    "&body=" + Uri.encode(bodyText);

Intent emailIntent = new Intent(Intent.ACTION_SENDTO);
emailIntent.setData(Uri.parse(mailto));

try {
  startActivity(emailIntent);
} catch (ActivityNotFoundException e) {
  //TODO: Handle case where no email app is available
}

And this is the link to his/her gist.

CSS: How can I set image size relative to parent height?

Use max-width property of CSS, like this :

img{
  max-width:100%;
}

Python DNS module import error

I was getting an error while using "import dns.resolver". I tried dnspython, py3dns but they failed. dns won't install. after much hit and try I installed pubdns module and it solved my problem.

System.Timers.Timer vs System.Threading.Timer

One important difference not mentioned above which might catch you out is that System.Timers.Timer silently swallows exceptions, whereas System.Threading.Timer doesn't.

For example:

var timer = new System.Timers.Timer { AutoReset = false };
timer.Elapsed += (sender, args) =>
{
    var z = 0;
    var i = 1 / z;
};
timer.Start();

vs

var timer = new System.Threading.Timer(x =>
{
    var z = 0;
    var i = 1 / z;
}, null, 0, Timeout.Infinite);

A non-blocking read on a subprocess.PIPE in Python

The select module helps you determine where the next useful input is.

However, you're almost always happier with separate threads. One does a blocking read the stdin, another does wherever it is you don't want blocked.

How to create python bytes object from long hex string?

You can do this with the hex codec. ie:

>>> s='000000000000484240FA063DE5D0B744ADBED63A81FAEA390000C8428640A43D5005BD44'
>>> s.decode('hex')
'\x00\x00\x00\x00\x00\x00HB@\xfa\x06=\xe5\xd0\xb7D\xad\xbe\xd6:\x81\xfa\xea9\x00\x00\xc8B\x86@\xa4=P\x05\xbdD'

How to check if a double value has no decimal part

Interesting little problem. It is a bit tricky, since real numbers, not always represent exact integers, even if they are meant to, so it's important to allow a tolerance.

For instance tolerance could be 1E-6, in the unit tests, I kept a rather coarse tolerance to have shorter numbers.

None of the answers that I can read now works in this way, so here is my solution:

public boolean isInteger(double n, double tolerance) {
    double absN = Math.abs(n);
    return Math.abs(absN - Math.round(absN)) <= tolerance;
}

And the unit test, to make sure it works:

@Test
public void checkIsInteger() {
    final double TOLERANCE = 1E-2;
    assertThat(solver.isInteger(1, TOLERANCE), is(true));

    assertThat(solver.isInteger(0.999, TOLERANCE), is(true));
    assertThat(solver.isInteger(0.9, TOLERANCE), is(false));

    assertThat(solver.isInteger(1.001, TOLERANCE), is(true));
    assertThat(solver.isInteger(1.1, TOLERANCE), is(false));

    assertThat(solver.isInteger(-1, TOLERANCE), is(true));

    assertThat(solver.isInteger(-0.999, TOLERANCE), is(true));
    assertThat(solver.isInteger(-0.9, TOLERANCE), is(false));

    assertThat(solver.isInteger(-1.001, TOLERANCE), is(true));        
    assertThat(solver.isInteger(-1.1, TOLERANCE), is(false));
}

Converting int to string in C

void itos(int value, char* str, size_t size) {
    snprintf(str, size, "%d", value);
}

..works with call by reference. Use it like this e.g.:

int someIntToParse;
char resultingString[length(someIntToParse)];

itos(someIntToParse, resultingString, length(someIntToParse));

now resultingString will hold your C-'string'.

How are SSL certificate server names resolved/Can I add alternative names using keytool?

How host name verification should be done is defined in RFC 6125, which is quite recent and generalises the practice to all protocols, and replaces RFC 2818, which was specific to HTTPS. (I'm not even sure Java 7 uses RFC 6125, which might be too recent for this.)

From RFC 2818 (Section 3.1):

If a subjectAltName extension of type dNSName is present, that MUST be used as the identity. Otherwise, the (most specific) Common Name field in the Subject field of the certificate MUST be used. Although the use of the Common Name is existing practice, it is deprecated and Certification Authorities are encouraged to use the dNSName instead.

[...]

In some cases, the URI is specified as an IP address rather than a hostname. In this case, the iPAddress subjectAltName must be present in the certificate and must exactly match the IP in the URI.

Essentially, the specific problem you have comes from the fact that you're using IP addresses in your CN and not a host name. Some browsers might work because not all tools follow this specification strictly, in particular because "most specific" in RFC 2818 isn't clearly defined (see discussions in RFC 6215).

If you're using keytool, as of Java 7, keytool has an option to include a Subject Alternative Name (see the table in the documentation for -ext): you could use -ext san=dns:www.example.com or -ext san=ip:10.0.0.1.

EDIT:

You can request a SAN in OpenSSL by changing openssl.cnf (it will pick the copy in the current directory if you don't want to edit the global configuration, as far as I remember, or you can choose an explicit location using the OPENSSL_CONF environment variable).

Set the following options (find the appropriate sections within brackets first):

[req]
req_extensions = v3_req

[ v3_req ]
subjectAltName=IP:10.0.0.1
# or subjectAltName=DNS:www.example.com

There's also a nice trick to use an environment variable for this (rather in than fixing it in a configuration file) here: http://www.crsr.net/Notes/SSL.html

How store a range from excel into a Range variable?

When you use a Range object, you cannot simply use the following syntax:

Dim myRange as Range
myRange = Range("A1")  

You must use the set keyword to assign Range objects:

Function getData(currentWorksheet As Worksheet, dataStartRow As Integer, dataEndRow As Integer, DataStartCol As Integer, dataEndCol As Integer)

    Dim dataTable As Range
    Set dataTable = currentWorksheet.Range(currentWorksheet.Cells(dataStartRow, DataStartCol), currentWorksheet.Cells(dataEndRow, dataEndCol))

    Set getData = dataTable

End Function

Sub main()
    Dim test As Range

    Set test = getData(ActiveSheet, 1, 3, 2, 5)
    test.select

End Sub

Note that every time a range is declared I use the Set keyword.


You can also allow your getData function to return a Range object instead of a Variant although this is unrelated to the problem you are having.

Proper usage of Java -D command-line parameters

That should be:

java -Dtest="true" -jar myApplication.jar

Then the following will return the value:

System.getProperty("test");

The value could be null, though, so guard against an exception using a Boolean:

boolean b = Boolean.parseBoolean( System.getProperty( "test" ) );

Note that the getBoolean method delegates the system property value, simplifying the code to:

if( Boolean.getBoolean( "test" ) ) {
   // ...
}

How to truncate string using SQL server

I think the answers here are great, but I would like to add a scenario.

Several times I've wanted to take a certain amount of characters off the front of a string, without worrying about it's length. There are several ways of doing this with RIGHT() and SUBSTRING(), but they all need to know the length of the string which can sometimes slow things down.

I've use the STUFF() function instead:

SET @Result = STUFF(@Result, 1, @LengthToRemove, '')

This replaces the length of unneeded string with an empty string.

Read only the first line of a file?

To go back to the beginning of an open file and then return the first line, do this:

my_file.seek(0)
first_line = my_file.readline()

Select data from date range between two dates

This query will help you:

select * 
from XXXX
where datepart(YYYY,create_date)>=2013 
and DATEPART(YYYY,create_date)<=2014

Uncaught TypeError: Cannot read property 'length' of undefined

You are accessing an object that is not defined.

The solution is check for null or undefined (to see whether the object exists) and only then iterate.

"query function not defined for Select2 undefined error"

Covered in this google group thread

The problem was because of the extra div that was being added by the select2. Select2 had added new div with class "select2-container form-select" to wrap the select created. So the next time i loaded the function, the error was being thrown as select2 was being attached to the div element. I changed my selector...

Prefix select2 css identifier with specific tag name "select":

$('select.form-select').select2();

Two divs side by side - Fluid display

This is easy with a flexbox:

_x000D_
_x000D_
#wrapper {_x000D_
  display: flex;_x000D_
}_x000D_
_x000D_
#left {_x000D_
  flex: 0 0 65%;_x000D_
}_x000D_
_x000D_
#right {_x000D_
  flex: 1;_x000D_
}
_x000D_
<div id="wrapper">_x000D_
  <div id="left">Left side div</div>_x000D_
  <div id="right">Right side div</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

What's the difference between the 'ref' and 'out' keywords?

ref tells the compiler that the object is initialized before entering the function, while out tells the compiler that the object will be initialized inside the function.

So while ref is two-ways, out is out-only.

no such file to load -- rubygems (LoadError)

This is the first answer when Googling 'require': cannot load such file -- ubygems (LoadError) after Google autocorrected "ubygems" to "rubygems". Turns out this was an intentional change between Ruby 2.4 and 2.5 (Bug #14322). Scripts that detect the user gems directory without taking into account the ruby version will most likely fail.

Ruby 2.4

ruby -rubygems -e 'puts Gem.user_dir'

Ruby 2.5

ruby -rrubygems -e 'puts Gem.user_dir'

Spring Boot application in eclipse, the Tomcat connector configured to listen on port XXXX failed to start

Issue: It's because either you are not stopping your application or the application is already somehow running on the same port somehow.

Solution, Before starting it another time, the earlier application needs to be killed and the port needs to be freed up.

Depending on your platform you can run the below commands to stop the application,

on windows

netstat -anp | find "your application port number"` --> find PID

taskkill /F /PID

on Linux,

netstat -ntpl | grep "your application port number"

kill pid // pid you will get from previous command

on Mac OS

lsof -n -iTCP:"port number"

kill pid //pid you will get from previous command

installing requests module in python 2.7 windows

  1. Download the source code(zip or rar package).
  2. Run the setup.py inside.

How to use timeit module

for me, this is the fastest way:

import timeit
def foo():
    print("here is my code to time...")


timeit.timeit(stmt=foo, number=1234567)

How to dynamically change the color of the selected menu item of a web page?

Assuming you want to change the colour of the currently selected link/tab... you're best bet is to apply a class (say active) to the currently selected link/tab and then style this differently.

Example style could be:

li.active, a.active {
  background-color: #f90;
}

Batch file to restart a service. Windows

net stop <your service> && net start <your service>

No net restart, unfortunately.

Using a batch to copy from network drive to C: or D: drive

Most importantly you need to mount the drive

net use z: \\yourserver\sharename

Of course, you need to make sure that the account the batch file runs under has permission to access the share. If you are doing this by using a Scheduled Task, you can choose the account by selecting the task, then:

  • right click Properties
  • click on General tab
  • change account under

"When running the task, use the following user account:" That's on Windows 7, it might be slightly different on different versions of Windows.

Then run your batch script with the following changes

copy "z:\FolderName" "C:\TEST_BACKUP_FOLDER"

Update just one gem with bundler

bundle update gem-name [--major|--patch|--minor]

This also works for dependencies.

In OS X Lion, LANG is not set to UTF-8, how to fix it?

I recently had the same issue on OS X Sierra with bash shell, and thanks to answers above I only had to edit the file

~/.bash_profile 

and append those lines

export LC_ALL=en_US.UTF-8
export LANG=en_US.UTF-8

how do I query sql for a latest record date for each user

SELECT t1.username, t1.date, value
FROM MyTable as t1
INNER JOIN (SELECT username, MAX(date)
            FROM MyTable
            GROUP BY username) as t2 ON  t2.username = t1.username AND t2.date = t1.date

How do I instantiate a Queue object in java?

enter image description here

The Queue interface extends java.util.Collection with additional insertion, extraction, and inspection operations like:

+offer(element: E): boolean // Inserting an element

+poll(): E // Retrieves the element and returns NULL if queue is empty

+remove(): E // Retrieves and removes the element and throws an Exception if queue is empty

+peek(): E // Retrieves,but does not remove, the head of this queue, returning null if this queue is empty.

+element(): E // Retrieves, but does not remove, the head of this queue, throws an exception if te queue is empty.

Example Code for implementing Queue:

java.util.Queue<String> queue = new LinkedList<>();
queue.offer("Hello");
queue.offer("StackOverFlow");
queue.offer("User");

System.out.println(queue.peek());

while (queue.size() > 0){
    System.out.println(queue.remove() + " ");
}
//Since Queue is empty now so this will return NULL
System.out.println(queue.peek());

Output Of the code :

Hello
Hello 
StackOverFlow 
User 
null

Using sessions & session variables in a PHP Login Script

$session_start();

extract($_POST);         
//extract data from submit post 

if(isset($submit))  
  {    
    if($user=="user" && $pass=="pass")    
      {     
        $_SESSION['user']= $user;       
        //if correct password and name store in session 
    } else {
        echo "Invalid user and password";
        header("Locatin:form.php")
    }
if(isset($_SESSION['user']))     
  {
  }

MySQL server has gone away - in exactly 60 seconds

Please see this link http://bugs.php.net/bug.php?id=45150 seems like they moved to native MYSQL support in PHP5.3 and it has some trouble working with IPV6. Try using "127.0.0.1" instead of "localhost"

Getting value of select (dropdown) before change

Track the value by hand.

var selects = jQuery("select.track_me");

selects.each(function (i, element) {
  var select = jQuery(element);
  var previousValue = select.val();
  select.bind("change", function () {
    var currentValue = select.val();

    // Use currentValue and previousValue
    // ...

    previousValue = currentValue;
  });
});

how to call url of any other website in php

As other's have mentioned, PHP's cURL functions will allow you to perform advanced HTTP requests. You can also use file_get_contents to access REST APIs:

$payload = file_get_contents('http://api.someservice.com/SomeMethod?param=value');

Starting with PHP 5 you can also create a stream context which will allow you to change headers or post data to the service.

Primary key or Unique index?

There are some disadvantages of CLUSTERED INDEXES vs UNIQUE INDEXES.

As already stated, a CLUSTERED INDEX physically orders the data in the table.

This mean that when you have a lot if inserts or deletes on a table containing a clustered index, everytime (well, almost, depending on your fill factor) you change the data, the physical table needs to be updated to stay sorted.

In relative small tables, this is fine, but when getting to tables that have GB's worth of data, and insertrs/deletes affect the sorting, you will run into problems.

Reload the page after ajax success

BrixenDK is right.

.ajaxStop() callback executed when all ajax call completed. This is a best place to put your handler.

$(document).ajaxStop(function(){
    window.location.reload();
});

phpexcel to download

Use this call

$objWriter->save('php://output');

To output the XLS sheet to the page you are on, just make sure that the page you are on has no other echo's,print's, outputs.

What is the difference between public, private, and protected?

Variables in PHP are cast in three different type:

Public : values of this variable types are available in all scope and call on execution of you code. declare as: public $examTimeTable;

Private: Values of this type of variable are only available on only to the class it belongs to. private $classRoomComputers;

Protected: Values of this class only and only available when Access been granted in a form of inheritance or their child class. generally used :: to grant access by parent class

protected $familyWealth;

Servlet Mapping using web.xml

It allows servlets to have multiple servlet mappings:

<servlet>
    <servlet-name>Servlet1</servlet-name>
    <servlet-path>foo.Servlet</servlet-path>
</servlet>
<servlet-mapping>
    <servlet-name>Servlet1</servlet-name>
    <url-pattern>/enroll</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>Servlet1</servlet-name>
    <url-pattern>/pay</url-pattern>
</servlet-mapping>
<servlet-mapping>
    <servlet-name>Servlet1</servlet-name>
    <url-pattern>/bill</url-pattern>
</servlet-mapping>

It allows filters to be mapped on the particular servlet:

<filter-mapping>
    <filter-name>Filter1</filter-name>
    <servlet-name>Servlet1</servlet-name>
</filter-mapping>

Your proposal would support neither of them. Note that the web.xml is read and parsed only once during application's startup, not on every HTTP request as you seem to think.

Since Servlet 3.0, there's the @WebServlet annotation which minimizes this boilerplate:

@WebServlet("/enroll")
public class Servlet1 extends HttpServlet {

See also:

Bootstrap fixed header and footer with scrolling body-content area in fluid-container

Add the following css to disable the default scroll:

body {
    overflow: hidden;
}

And change the #content css to this to make the scroll only on content body:

#content {
    max-height: calc(100% - 120px);
    overflow-y: scroll;
    padding: 0px 10%;
    margin-top: 60px;
}

See fiddle here.


Edit:

Actually, I'm not sure what was the issue you were facing, since it seems that your css is working. I have only added the HTML and the header css statement:

_x000D_
_x000D_
html {_x000D_
  height: 100%;_x000D_
}_x000D_
html body {_x000D_
  height: 100%;_x000D_
  overflow: hidden;_x000D_
}_x000D_
html body .container-fluid.body-content {_x000D_
  position: absolute;_x000D_
  top: 50px;_x000D_
  bottom: 30px;_x000D_
  right: 0;_x000D_
  left: 0;_x000D_
  overflow-y: auto;_x000D_
}_x000D_
header {_x000D_
    position: absolute;_x000D_
    left: 0;_x000D_
    right: 0;_x000D_
    top: 0;_x000D_
    background-color: #4C4;_x000D_
    height: 50px;_x000D_
}_x000D_
footer {_x000D_
    position: absolute;_x000D_
    left: 0;_x000D_
    right: 0;_x000D_
    bottom: 0;_x000D_
    background-color: #4C4;_x000D_
    height: 30px;_x000D_
}
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
<header></header>_x000D_
<div class="container-fluid body-content">_x000D_
  Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>_x000D_
  Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>_x000D_
  Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>_x000D_
  Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>_x000D_
  Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>_x000D_
</div>_x000D_
<footer></footer>
_x000D_
_x000D_
_x000D_

What is the difference between Python and IPython?

IPython is basically the "recommended" Python shell, which provides extra features. There is no language called IPython.

how to write javascript code inside php

You can put up all your JS like this, so it doesn't execute before your HTML is ready

$(document).ready(function() {
   // some code here
 });

Remember this is jQuery so include it in the head section. Also see Why you should use jQuery and not onload

How to close a web page on a button click, a hyperlink or a link button click?

double click the button and add write // this.close();

  private void buttonClick(object sender, EventArgs e)
{
    this.Close();
}

specifying goal in pom.xml

I stumbled upon this exception, and found out that I forgot to add a Main.
Check out if you have public static void main(String[] args) correctly.

Good luck!

Importing Excel spreadsheet data into another Excel spreadsheet containing VBA

Data can be pulled into an excel from another excel through Workbook method or External reference or through Data Import facility.

If you want to read or even if you want to update another excel workbook, these methods can be used. We may not depend only on VBA for this.

For more info on these techniques, please click here to refer the article

Where to find free public Web Services?

Here you can find some public REST services for encryption and security related things: http://security.jelastic.servint.net

HttpWebRequest using Basic authentication

I finally got it!

string url = @"https://telematicoprova.agenziadogane.it/TelematicoServiziDiUtilitaWeb/ServiziDiUtilitaAutServlet?UC=22&SC=1&ST=2";
WebRequest request = WebRequest.Create(url);
request.Credentials = GetCredential();
request.PreAuthenticate = true;

and this is GetCredential()

private CredentialCache GetCredential()
{
    string url = @"https://telematicoprova.agenziadogane.it/TelematicoServiziDiUtilitaWeb/ServiziDiUtilitaAutServlet?UC=22&SC=1&ST=2";
    ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
    CredentialCache credentialCache = new CredentialCache();
    credentialCache.Add(new System.Uri(url), "Basic", new NetworkCredential(ConfigurationManager.AppSettings["ead_username"], ConfigurationManager.AppSettings["ead_password"]));
    return credentialCache;
}

YAY!

Angular 2 Scroll to top on Route Change

just do it easy with click action

in your main component html make reference #scrollContainer

<div class="main-container" #scrollContainer>
    <router-outlet (activate)="onActivate($event, scrollContainer)"></router-outlet>
</div>

in main component .ts

onActivate(e, scrollContainer) {
    scrollContainer.scrollTop = 0;
}

Ignore case in Python strings

I'm pretty sure you either have to use .lower() or use a regular expression. I'm not aware of a built-in case-insensitive string comparison function.

Should MySQL have its timezone set to UTC?

The pros and cons are pretty much identical.It depends on whether you want this or not.

Be careful, if MySQL timezone differs from your system time (for instance PHP), comparing the time or printing to the user will involve some tinkering.

How to print matched regex pattern using awk?

gawk can get the matching part of every line using this as action:

{ if (match($0,/your regexp/,m)) print m[0] }

match(string, regexp [, array]) If array is present, it is cleared, and then the zeroth element of array is set to the entire portion of string matched by regexp. If regexp contains parentheses, the integer-indexed elements of array are set to contain the portion of string matching the corresponding parenthesized subexpression. http://www.gnu.org/software/gawk/manual/gawk.html#String-Functions

PYODBC--Data source name not found and no default driver specified

Apart from the other answers, that considered the connection string itself, it might simply be necessary to download the correct odbc driver. My client just faced this issue when executing a python app, that required it. you can check this by pressing windows + typing "odbc". the correct driver should appear in the drivers tab.

What is the difference between Subject and BehaviorSubject?

BehaviourSubject

BehaviourSubject will return the initial value or the current value on Subscription

var bSubject= new Rx.BehaviorSubject(0);  // 0 is the initial value

bSubject.subscribe({
  next: (v) => console.log('observerA: ' + v)  // output initial value, then new values on `next` triggers
});

bSubject.next(1);  // output new value 1 for 'observer A'
bSubject.next(2);  // output new value 2 for 'observer A', current value 2 for 'Observer B' on subscription

bSubject.subscribe({
  next: (v) => console.log('observerB: ' + v)  // output current value 2, then new values on `next` triggers
});

bSubject.next(3);

With output:

observerA: 0
observerA: 1
observerA: 2
observerB: 2
observerA: 3
observerB: 3

Subject

Subject does not return the current value on Subscription. It triggers only on .next(value) call and return/output the value

var subject = new Rx.Subject();

subject.next(1); //Subjects will not output this value

subject.subscribe({
  next: (v) => console.log('observerA: ' + v)
});
subject.subscribe({
  next: (v) => console.log('observerB: ' + v)
});

subject.next(2);
subject.next(3);

With the following output on the console:

observerA: 2
observerB: 2
observerA: 3
observerB: 3

How to automate browsing using python?

There are plenty of built in python modules that whould help with this. For example urllib and htmllib.

The problem will be simpler if you change the way you're approaching it. You say you want to "fill some forms, click submit button, send the data back to server, recieve the response", which sounds like a four stage process.

In fact, what you need to do is post some data to a webserver and get a response.

This is as simple as:

>>> import urllib
>>> params = urllib.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
>>> f = urllib.urlopen("http://www.musi-cal.com/cgi-bin/query", params)
>>> print f.read()

(example taken from the urllib docs).

What you do with the response depends on how complex the HTML is and what you want to do with it. You might get away with parsing it using a regular expression or two, or you can use the htmllib.HTMLParser class, or maybe a higher level more flexible parser like Beautiful Soup.

Regular expression for a hexadecimal number?

The exact syntax depends on your exact requirements and programming language, but basically:

/[0-9a-fA-F]+/

or more simply, i makes it case-insensitive.

/[0-9a-f]+/i

If you are lucky enough to be using Ruby, you can do:

/\h+/

EDIT - Steven Schroeder's answer made me realise my understanding of the 0x bit was wrong, so I've updated my suggestions accordingly. If you also want to match 0x, the equivalents are

/0[xX][0-9a-fA-F]+/
/0x[0-9a-f]+/i
/0x[\h]+/i

ADDED MORE - If 0x needs to be optional (as the question implies):

/(0x)?[0-9a-f]+/i

Node.js client for a socket.io server

Client side code: I had a requirement where my nodejs webserver should work as both server as well as client, so i added below code when i need it as client, It should work fine, i am using it and working fine for me!!!

const socket = require('socket.io-client')('http://192.168.0.8:5000', {
            reconnection: true,
            reconnectionDelay: 10000
          });
    
        socket.on('connect', (data) => {
            console.log('Connected to Socket');
        });
        
        socket.on('event_name', (data) => {
            console.log("-----------------received event data from the socket io server");
        });
    
        //either 'io server disconnect' or 'io client disconnect'
        socket.on('disconnect', (reason) => {
            console.log("client disconnected");
            if (reason === 'io server disconnect') {
              // the disconnection was initiated by the server, you need to reconnect manually
              console.log("server disconnected the client, trying to reconnect");
              socket.connect();
            }else{
                console.log("trying to reconnect again with server");
            }
            // else the socket will automatically try to reconnect
          });
    
        socket.on('error', (error) => {
            console.log(error);
        });

Pass accepts header parameter to jquery ajax

Although some of them are correct, I've found quite confusing the previous responses. At the same time, the OP asked for a solution without setting a custom header or using beforeSend, so I've being looking for a clearer explanation. I hope my conclusions provide some light to others.

The code

jQuery.ajax({
    .... 
    accepts: "application/json; charset=utf-8",
    ....
});

doesn't work because accepts must be a PlainObject (not a String) according to the jQuery doc (http://api.jquery.com/jquery.ajax/). Specifically, jQuery expect zero or more key-value pairs relating each dataType with the accepted MIME type for them. So what I've finally using is:

jQuery.ajax({
    ....
    dataType: 'json',
    accepts: {
        json: 'application/json'
    },
    ....
});

Install .ipa to iPad with or without iTunes

I try to face with these problems and I use : https://www.installonair.com . It's free and not have limit like diawi.

  1. You need to add device UDID to apple developer account devices part.
  2. Build your project and archieve it ad hoc with your certificate
  3. Open that link and upload your ad hoc ipa file to website
  4. Get qr code and link to download.

Flutter command not found

If your are facing this issue from a Windows 10, that's how i solved this

first of all, find your flutter path, and than your bin folder under de flutter path

e.g. "C:\flutter\bin"

copy it, then pres the windows button, type: environment, and press "Edit the system environment variable"

press "environment variable" button

double click on "Path" menu

Add a new path, using the bin address

e.g ""C:\flutter\bin"

this should work

bash "if [ false ];" returns true instead of false -- why?

Using true/false removes some bracket clutter...

#! /bin/bash    
#  true_or_false.bash

[ "$(basename $0)" == "bash" ] && sourced=true || sourced=false

$sourced && echo "SOURCED"
$sourced || echo "CALLED"

# Just an alternate way:
! $sourced  &&  echo "CALLED " ||  echo "SOURCED"

$sourced && return || exit

How can I perform a str_replace in JavaScript, replacing text in JavaScript?

Using regex for string replacement is significantly slower than using a string replace.
As demonstrated on JSPerf, you can have different levels of efficiency for creating a regex, but all of them are significantly slower than a simple string replace. The regex is slower because:

Fixed-string matches don't have backtracking, compilation steps, ranges, character classes, or a host of other features that slow down the regular expression engine. There are certainly ways to optimize regex matches, but I think it's unlikely to beat indexing into a string in the common case.

For a simple test run on the JS perf page, I've documented some of the results:

_x000D_
_x000D_
<script>_x000D_
// Setup_x000D_
  var startString = "xxxxxxxxxabcxxxxxxabcxx";_x000D_
  var endStringRegEx = undefined;_x000D_
  var endStringString = undefined;_x000D_
  var endStringRegExNewStr = undefined;_x000D_
  var endStringRegExNew = undefined;_x000D_
  var endStringStoredRegEx = undefined;      _x000D_
  var re = new RegExp("abc", "g");_x000D_
</script>_x000D_
_x000D_
<script>_x000D_
// Tests_x000D_
  endStringRegEx = startString.replace(/abc/g, "def") // Regex_x000D_
  endStringString = startString.replace("abc", "def", "g") // String_x000D_
  endStringRegExNewStr = startString.replace(new RegExp("abc", "g"), "def"); // New Regex String_x000D_
  endStringRegExNew = startString.replace(new RegExp(/abc/g), "def"); // New Regexp_x000D_
  endStringStoredRegEx = startString.replace(re, "def") // saved regex_x000D_
</script>
_x000D_
_x000D_
_x000D_

The results for Chrome 68 are as follows:

String replace:    9,936,093 operations/sec
Saved regex:       5,725,506 operations/sec
Regex:             5,529,504 operations/sec
New Regex String:  3,571,180 operations/sec
New Regex:         3,224,919 operations/sec

From the sake of completeness of this answer (borrowing from the comments), it's worth mentioning that .replace only replaces the first instance of the matched character. Its only possible to replace all instances with //g. The performance trade off and code elegance could be argued to be worse if replacing multiple instances name.replace(' ', '_').replace(' ', '_').replace(' ', '_'); or worse while (name.includes(' ')) { name = name.replace(' ', '_') }

Video auto play is not working in Safari and Chrome desktop browser

I started out with playing all the visible videos, but old phones weren't performing well. So right now I play the one video that's closest to the center of the window and pause the rest. Vanilla JS. You can pick which algorithm you prefer.

//slowLooper(playAllVisibleVideos);
slowLooper(playVideoClosestToCenter);

function isVideoPlaying(elem) {
    if (elem.paused || elem.ended || elem.readyState < 2) {
        return false;
    } else {
        return true;
    }
}
function isScrolledIntoView(el) {
    var elementTop = el.getBoundingClientRect().top;
    var elementBottom = el.getBoundingClientRect().bottom;
    var isVisible = elementTop < window.innerHeight && elementBottom >= 0;
    return isVisible;
}
function playVideoClosestToCenter() {
    var vids = document.querySelectorAll('video');
    var smallestDistance = null;
    var smallestDistanceI = null;
    for (var i = 0; i < vids.length; i++) {
        var el = vids[i];
        var elementTop = el.getBoundingClientRect().top;
        var elementBottom = el.getBoundingClientRect().bottom;
        var elementCenter = (elementBottom + elementTop) / 2.0;
        var windowCenter = window.innerHeight / 2.0;
        var distance = Math.abs(windowCenter - elementCenter);
        if (smallestDistance === null || distance < smallestDistance) {
            smallestDistance = distance;
            smallestDistanceI = i;
        }
    }
    if (smallestDistanceI !== null) {
        vids[smallestDistanceI].play();
        for (var i = 0; i < vids.length; i++) {
            if (i !== smallestDistanceI) {
                vids[i].pause();
            }
        }
    }
}
function playAllVisibleVideos(timestamp) {
    // This fixes autoplay for safari
    var vids = document.querySelectorAll('video');
    for (var i = 0; i < vids.length; i++) {
        if (isVideoPlaying(vids[i]) && !isScrolledIntoView(vids[i])) {
            vids[i].pause();
        }
        if (!isVideoPlaying(vids[i]) && isScrolledIntoView(vids[i])) {
            vids[i].play();
        }
    }
}
function slowLooper(cb) {
    // Throttling requestAnimationFrame to a few fps so we don't waste cpu on this
    // We could have listened to scroll+resize+load events which move elements
    // but that would have been more complicated.
    function repeats() {
        cb();
        setTimeout(function() {
            window.requestAnimationFrame(repeats);
        }, 200);
    }
    repeats();
}

What is the point of "final class" in Java?

Android Looper class is a good practical example of this. http://developer.android.com/reference/android/os/Looper.html

The Looper class provides certain functionality which is NOT intended to be overridden by any other class. Hence, no sub-class here.

How to match hyphens with Regular Expression?

The hyphen is usually a normal character in regular expressions. Only if it’s in a character class and between two other characters does it take a special meaning.

Thus:

  • [-] matches a hyphen.
  • [abc-] matches a, b, c or a hyphen.
  • [-abc] matches a, b, c or a hyphen.
  • [ab-d] matches a, b, c or d (only here the hyphen denotes a character range).

Folder is locked and I can't unlock it

In addition to David M's answer, while doing cleanup -> check 'break locks' option. This will ensure release of locks. Then do svn update. This worked for me.

what is the difference between GROUP BY and ORDER BY in sql

They have totally different meaning and aren't really related at all.

ORDER BY allows you to sort the result set according to different criteria, such as first sort by name from a-z, then sort by the price highest to lowest.

(ORDER BY name, price DESC)

GROUP BY allows you to take your result set, group it into logical groups and then run aggregate queries on those groups. You could for instance select all employees, group them by their workplace location and calculate the average salary of all employees of each workplace location.

Which exception should I raise on bad/illegal argument combinations in Python?

I would just raise ValueError, unless you need a more specific exception..

def import_to_orm(name, save=False, recurse=False):
    if recurse and not save:
        raise ValueError("save must be True if recurse is True")

There's really no point in doing class BadValueError(ValueError):pass - your custom class is identical in use to ValueError, so why not use that?

What is a mixin, and why are they useful?

Maybe an example from ruby can help:

You can include the mixin Comparable and define one function "<=>(other)", the mixin provides all those functions:

<(other)
>(other)
==(other)
<=(other)
>=(other)
between?(other)

It does this by invoking <=>(other) and giving back the right result.

"instance <=> other" returns 0 if both objects are equal, less than 0 if instance is bigger than other and more than 0 if other is bigger.

The VMware Authorization Service is not running

This problem was solved for me by running VMware workstation as Windows administrator. From the start menu right click on the VMware workstation, then select "Run as Administrator"

how to get param in method post spring mvc?

  1. Spring annotations will work fine if you remove enctype="multipart/form-data".

    @RequestParam(value="txtEmail", required=false)
    
  2. You can even get the parameters from the request object .

    request.getParameter(paramName);
    
  3. Use a form in case the number of attributes are large. It will be convenient. Tutorial to get you started.

  4. Configure the Multi-part resolver if you want to receive enctype="multipart/form-data".

    <bean id="multipartResolver"
      class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="maxUploadSize" value="250000"/>
    </bean>
    

Refer the Spring documentation.

Python dict how to create key or append an element to key?

You can use defaultdict in collections.

An example from doc:

s = [('yellow', 1), ('blue', 2), ('yellow', 3), ('blue', 4), ('red', 1)]
d = defaultdict(list)
for k, v in s:
    d[k].append(v)

What's the difference between :: (double colon) and -> (arrow) in PHP?

Yes, I just hit my first 'PHP Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM'. My bad, I had a $instance::method() that should have been $instance->method(). Silly me.

The odd thing is that this still works just fine on my local machine (running PHP 5.3.8) - nothing, not even a warning with error_reporting = E_ALL - but not at all on the test server, there it just explodes with a syntax error and a white screen in the browser. Since PHP logging was turned off at the test machine, and the hosting company was too busy to turn it on, it was not too obvious.

So, word of warning: apparently, some PHP installations will let you use a $instance::method(), while others don't.

If anybody can expand on why that is, please do.

Is there a 'box-shadow-color' property?

You could use a CSS pre-processor to do your skinning. With Sass you can do something similar to this:

_theme1.scss:

$theme-primary-color: #a00;
$theme-secondary-color: #d00;
// etc.

_theme2.scss:

$theme-primary-color: #666;
$theme-secondary-color: #ccc;
// etc.

styles.scss:

// import whichever theme you want to use
@import 'theme2';

-webkit-box-shadow: inset 0px 0px 2px $theme-primary-color;
-moz-box-shadow: inset 0px 0px 2px $theme-primary-color;

If it's not site wide theming but class based theming you need, then you can do this: http://codepen.io/jjenzz/pen/EaAzo

How to check if string input is a number?

while True:
    b1=input('Type a number:')
    try:
        a1=int(b1)
    except ValueError:
        print ('"%(a1)s" is not a number. Try again.' %{'a1':b1})       
    else:
        print ('You typed "{}".'.format(a1))
        break

This makes a loop to check whether input is an integer or not, result would look like below:

>>> %Run 1.1.py
Type a number:d
"d" is not a number. Try again.
Type a number:
>>> %Run 1.1.py
Type a number:4
You typed 4.
>>> 

Can't access Tomcat using IP address

No solution mentioned above was solved my problem. My problem was different.

First check is your port is disabled in firewall. Go to Control Panel -> Windows Firewall -> Advance Settings -> Inbound Rules and see any port is blocked.

A sample image is below:

enter image description here

If so then you can unblock the port by following steps:

Step 1:

enter image description here

Here you can see that the port is blocked.

enter image description here

Step 2: Allow the connection -> Apply -> Ok.

enter image description here

That's solved my blocked problem. Happy coding :) :)

Moving from position A to position B slowly with animation

I don't understand why other answers are about relative coordinates change, not absolute like OP asked in title.

$("#Friends").animate( {top:
  "-=" + (parseInt($("#Friends").css("top")) - 100) + "px"
} );

Difference between Subquery and Correlated Subquery

Above example is not Co-related Sub-Query. It is Derived Table / Inline-View since i.e, a Sub-query within FROM Clause.

A Corelated Sub-query should refer its parent(main Query) Table in it. For example See find the Nth max salary by Co-related Sub-query:

SELECT Salary 
FROM Employee E1
WHERE N-1 = (SELECT COUNT(*)
             FROM Employee E2
             WHERE E1.salary <E2.Salary) 

Co-Related Vs Nested-SubQueries.

Technical difference between Normal Sub-query and Co-related sub-query are:

1. Looping: Co-related sub-query loop under main-query; whereas nested not; therefore co-related sub-query executes on each iteration of main query. Whereas in case of Nested-query; subquery executes first then outer query executes next. Hence, the maximum no. of executes are NXM for correlated subquery and N+M for subquery.

2. Dependency(Inner to Outer vs Outer to Inner): In the case of co-related subquery, inner query depends on outer query for processing whereas in normal sub-query, Outer query depends on inner query.

3.Performance: Using Co-related sub-query performance decreases, since, it performs NXM iterations instead of N+M iterations. ¨ Co-related Sub-query Execution.

For more information with examples :

http://dotnetauthorities.blogspot.in/2013/12/Microsoft-SQL-Server-Training-Online-Learning-Classes-Sql-Sub-Queries-Nested-Co-related.html

Escaping single quotes in JavaScript string for JavaScript evaluation

There are two ways to escaping the single quote in JavaScript.

1- Use double-quote or backticks to enclose the string.

Example: "fsdsd'4565sd" or `fsdsd'4565sd`.

2- Use backslash before any special character, In our case is the single quote

Example:strInputString = strInputString.replace(/ ' /g, " \\' ");

Note: use a double backslash.

Both methods work for me.

Php - Your PHP installation appears to be missing the MySQL extension which is required by WordPress

If people are using shared Linux hosting with cPanel (Godaddy, Reseller club, Hostgator or any Shared Hosting), try the following:

Under Software and Services tab -> Select PHP Version -> PHP Selectors | Extentions

Tick all MySQL related extensions, save it and you are done. Please check the attached image.

Image showing the extensions in cPanel

How to iterate over a column vector in Matlab?

for i=1:length(list)
  elm = list(i);
  //do something with elm.

Can a constructor in Java be private?

Yes, class can have a private constructor. It is needed as to disallow to access the constructor from other classes and remain it accessible within defined class.

Why would you want objects of your class to only be created internally? This could be done for any reason, but one possible reason is that you want to implement a singleton. A singleton is a design pattern that allows only one instance of your class to be created, and this can be accomplished by using a private constructor.

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException

i don't see any for loop to initalize the variables.you can do something like this.

for(i=0;i<50;i++){
 /* Code which is necessary with a simple if statement*/

   }

Get int from String, also containing letters, in Java

You can also use Scanner :

Scanner s = new Scanner(MyString);
s.nextInt();

How can I output a UTF-8 CSV in PHP that Excel will read properly?

The CSV File musst include a Byte Order Mark.

Or as suggested and workaround just echo it with the HTTP body

How to check if a file exists from a url

Do a request with curl and see if it returns a 404 status code. Do the request using the HEAD request method so it only returns the headers without a body.

Counting the number of files in a directory using Java

public void shouldGetTotalFilesCount() {
    Integer reduce = of(listRoots()).parallel().map(this::getFilesCount).reduce(0, ((a, b) -> a + b));
}

private int getFilesCount(File directory) {
    File[] files = directory.listFiles();
    return Objects.isNull(files) ? 1 : Stream.of(files)
            .parallel()
            .reduce(0, (Integer acc, File p) -> acc + getFilesCount(p), (a, b) -> a + b);
}

How to convert a Hibernate proxy to a real entity object

I've written following code which cleans object from proxies (if they are not already initialized)

public class PersistenceUtils {

    private static void cleanFromProxies(Object value, List<Object> handledObjects) {
        if ((value != null) && (!isProxy(value)) && !containsTotallyEqual(handledObjects, value)) {
            handledObjects.add(value);
            if (value instanceof Iterable) {
                for (Object item : (Iterable<?>) value) {
                    cleanFromProxies(item, handledObjects);
                }
            } else if (value.getClass().isArray()) {
                for (Object item : (Object[]) value) {
                    cleanFromProxies(item, handledObjects);
                }
            }
            BeanInfo beanInfo = null;
            try {
                beanInfo = Introspector.getBeanInfo(value.getClass());
            } catch (IntrospectionException e) {
                // LOGGER.warn(e.getMessage(), e);
            }
            if (beanInfo != null) {
                for (PropertyDescriptor property : beanInfo.getPropertyDescriptors()) {
                    try {
                        if ((property.getWriteMethod() != null) && (property.getReadMethod() != null)) {
                            Object fieldValue = property.getReadMethod().invoke(value);
                            if (isProxy(fieldValue)) {
                                fieldValue = unproxyObject(fieldValue);
                                property.getWriteMethod().invoke(value, fieldValue);
                            }
                            cleanFromProxies(fieldValue, handledObjects);
                        }
                    } catch (Exception e) {
                        // LOGGER.warn(e.getMessage(), e);
                    }
                }
            }
        }
    }

    public static <T> T cleanFromProxies(T value) {
        T result = unproxyObject(value);
        cleanFromProxies(result, new ArrayList<Object>());
        return result;
    }

    private static boolean containsTotallyEqual(Collection<?> collection, Object value) {
        if (CollectionUtils.isEmpty(collection)) {
            return false;
        }
        for (Object object : collection) {
            if (object == value) {
                return true;
            }
        }
        return false;
    }

    public static boolean isProxy(Object value) {
        if (value == null) {
            return false;
        }
        if ((value instanceof HibernateProxy) || (value instanceof PersistentCollection)) {
            return true;
        }
        return false;
    }

    private static Object unproxyHibernateProxy(HibernateProxy hibernateProxy) {
        Object result = hibernateProxy.writeReplace();
        if (!(result instanceof SerializableProxy)) {
            return result;
        }
        return null;
    }

    @SuppressWarnings("unchecked")
    private static <T> T unproxyObject(T object) {
        if (isProxy(object)) {
            if (object instanceof PersistentCollection) {
                PersistentCollection persistentCollection = (PersistentCollection) object;
                return (T) unproxyPersistentCollection(persistentCollection);
            } else if (object instanceof HibernateProxy) {
                HibernateProxy hibernateProxy = (HibernateProxy) object;
                return (T) unproxyHibernateProxy(hibernateProxy);
            } else {
                return null;
            }
        }
        return object;
    }

    private static Object unproxyPersistentCollection(PersistentCollection persistentCollection) {
        if (persistentCollection instanceof PersistentSet) {
            return unproxyPersistentSet((Map<?, ?>) persistentCollection.getStoredSnapshot());
        }
        return persistentCollection.getStoredSnapshot();
    }

    private static <T> Set<T> unproxyPersistentSet(Map<T, ?> persistenceSet) {
        return new LinkedHashSet<T>(persistenceSet.keySet());
    }

}

I use this function over result of my RPC services (via aspects) and it cleans recursively all result objects from proxies (if they are not initialized).

check android application is in foreground or not?

I don't understand what you want, but You can detect currently foreground/background application with ActivityManager.getRunningAppProcesses() call.

Something like,

class ForegroundCheckTask extends AsyncTask<Context, Void, Boolean> {

  @Override
  protected Boolean doInBackground(Context... params) {
    final Context context = params[0].getApplicationContext();
    return isAppOnForeground(context);
  }

  private boolean isAppOnForeground(Context context) {
    ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    List<RunningAppProcessInfo> appProcesses = activityManager.getRunningAppProcesses();
    if (appProcesses == null) {
      return false;
    }
    final String packageName = context.getPackageName();
    for (RunningAppProcessInfo appProcess : appProcesses) {
      if (appProcess.importance == RunningAppProcessInfo.IMPORTANCE_FOREGROUND && appProcess.processName.equals(packageName)) {
        return true;
      }
    }
    return false;
  }
}

// Use like this:
boolean foregroud = new ForegroundCheckTask().execute(context).get();

Also let me know if I misunderstand..

UPDATE: Look at this SO question Determining the current foreground application from a background task or service fore more information..

Thanks..

Angular and debounce

We can create a [debounce] directive which overwrites ngModel's default viewToModelUpdate function with an empty one.

Directive Code

@Directive({ selector: '[debounce]' })
export class MyDebounce implements OnInit {
    @Input() delay: number = 300;

    constructor(private elementRef: ElementRef, private model: NgModel) {
    }

    ngOnInit(): void {
        const eventStream = Observable.fromEvent(this.elementRef.nativeElement, 'keyup')
            .map(() => {
                return this.model.value;
            })
            .debounceTime(this.delay);

        this.model.viewToModelUpdate = () => {};

        eventStream.subscribe(input => {
            this.model.viewModel = input;
            this.model.update.emit(input);
        });
    }
}

How to use it

<div class="ui input">
  <input debounce [delay]=500 [(ngModel)]="myData" type="text">
</div>

The APR based Apache Tomcat Native library was not found on the java.library.path

Regarding the original question asked in the title ...

  • sudo apt-get install libtcnative-1

  • or if you are on RHEL Linux yum install tomcat-native

The documentation states you need http://tomcat.apache.org/native-doc/

  • sudo apt-get install libapr1.0-dev libssl-dev
  • or RHEL yum install apr-devel openssl-devel

rotating axis labels in R

Use par(las=1).

See ?par:

las
numeric in {0,1,2,3}; the style of axis labels.
0: always parallel to the axis [default],
1: always horizontal,
2: always perpendicular to the axis,
3: always vertical.