Programs & Examples On #Timing

timing is a numerical measurement of the how long it takes to execute an instruction or series of instructions

Hide div after a few seconds

Using the jQuery timer will also allow you to have a name associated with the timers that are attached to the object. So you could attach several timers to an object and stop any one of them.

$("#myid").oneTime(1000, "mytimer1" function() {
  $("#something").hide();
}).oneTime(2000, "mytimer2" function() {
  $("#somethingelse").show();  
});

$("#myid").stopTime("mytimer2");

The eval function (and its relatives, Function, setTimeout, and setInterval) provide access to the JavaScript compiler. This is sometimes necessary, but in most cases it indicates the presence of extremely bad coding. The eval function is the most misused feature of JavaScript.

http://www.jslint.com/lint.html

How to make `setInterval` behave more in sync, or how to use `setTimeout` instead?

The best way to deal with audio timing is with the Web Audio Api, it has a separate clock that is accurate regardless of what is happening in the main thread. There is a great explanation, examples, etc from Chris Wilson here:

http://www.html5rocks.com/en/tutorials/audio/scheduling/

Have a look around this site for more Web Audio API, it was developed to do exactly what you are after.

Is it possible to get a history of queries made in postgres

If you want to identify slow queries, than the method is to use log_min_duration_statement setting (in postgresql.conf or set per-database with ALTER DATABASE SET).

When you logged the data, you can then use grep or some specialized tools - like pgFouine or my own analyzer - which lacks proper docs, but despite this - runs quite well.

How do I time a method's execution in Java?

I basically do variations of this, but considering how hotspot compilation works, if you want to get accurate results you need to throw out the first few measurements and make sure you are using the method in a real world (read application specific) application.

If the JIT decides to compile it your numbers will vary heavily. so just be aware

What is the Python equivalent of Matlab's tic and toc functions?

pip install easy-tictoc

In the code:

from tictoc import tic, toc

tic()

#Some code

toc()

Disclaimer: I'm the author of this library.

Best timing method in C?

gettimeofday() will probably do what you want.

If you're on Intel hardware, here's how to read the CPU real-time instruction counter. It will tell you the number of CPU cycles executed since the processor was booted. This is probably the finest-grained, lowest overhead counter you can get for performance measurement.

Note that this is the number of CPU cycles. On linux you can get the CPU speed from /proc/cpuinfo and divide to get the number of seconds. Converting this to a double is quite handy.

When I run this on my box, I get

11867927879484732
11867927879692217
it took this long to call printf: 207485

Here's the Intel developer's guide that gives tons of detail.

#include <stdio.h>
#include <stdint.h>

inline uint64_t rdtsc() {
    uint32_t lo, hi;
    __asm__ __volatile__ (
      "xorl %%eax, %%eax\n"
      "cpuid\n"
      "rdtsc\n"
      : "=a" (lo), "=d" (hi)
      :
      : "%ebx", "%ecx");
    return (uint64_t)hi << 32 | lo;
}

main()
{
    unsigned long long x;
    unsigned long long y;
    x = rdtsc();
    printf("%lld\n",x);
    y = rdtsc();
    printf("%lld\n",y);
    printf("it took this long to call printf: %lld\n",y-x);
}

Spring MVC Multipart Request with JSON

As documentation says:

Raised when the part of a "multipart/form-data" request identified by its name cannot be found.

This may be because the request is not a multipart/form-data either because the part is not present in the request, or because the web application is not configured correctly for processing multipart requests -- e.g. no MultipartResolver.

How to use multiprocessing pool.map with multiple arguments?

for python2, you can use this trick

def fun(a,b):
    return a+b

pool = multiprocessing.Pool(processes=6)
b=233
pool.map(lambda x:fun(x,b),range(1000))

How to set tint for an image view programmatically in android?

I found that we can use color selector for tint attr:

mImageView.setEnabled(true);

activity_main.xml:

<ImageView
    android:id="@+id/image_view"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_arrowup"
    android:tint="@color/section_arrowup_color" />

section_arrowup_color.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="@android:color/white" android:state_enabled="true"/>
    <item android:color="@android:color/black" android:state_enabled="false"/>
    <item android:color="@android:color/white"/>
</selector>

Getting msbuild.exe without installing Visual Studio

The latest (as of Jan 2019) stand-alone MSBuild installers can be found here: https://www.visualstudio.com/downloads/

Scroll down to "Tools for Visual Studio 2019" and choose "Build Tools for Visual Studio 2019" (despite the name, it's for users who don't want the full IDE)

See this question for additional information.

Removing nan values from an array

Doing the above :

x = x[~numpy.isnan(x)]

or

x = x[numpy.logical_not(numpy.isnan(x))]

I found that resetting to the same variable (x) did not remove the actual nan values and had to use a different variable. Setting it to a different variable removed the nans. e.g.

y = x[~numpy.isnan(x)]

Angular : Manual redirect to route

Angular routing : Manual navigation

First you need to import the angular router :

import {Router} from "@angular/router"

Then inject it in your component constructor :

constructor(private router: Router) { }

And finally call the .navigate method anywhere you need to "redirect" :

this.router.navigate(['/your-path'])

You can also put some parameters on your route, like user/5 :

this.router.navigate(['/user', 5])

Documentation: Angular official documentaiton

How to display image with JavaScript?

You could make use of the Javascript DOM API. In particular, look at the createElement() method.

You could create a re-usable function that will create an image like so...

function show_image(src, width, height, alt) {
    var img = document.createElement("img");
    img.src = src;
    img.width = width;
    img.height = height;
    img.alt = alt;

    // This next line will just add it to the <body> tag
    document.body.appendChild(img);
}

Then you could use it like this...

<button onclick=
    "show_image('http://google.com/images/logo.gif', 
                 276, 
                 110, 
                 'Google Logo');">Add Google Logo</button> 

See a working example on jsFiddle: http://jsfiddle.net/Bc6Et/

Can't compile C program on a Mac after upgrade to Mojave

I had the same issue with Golang (debugging with Goland) after migration. The only (ridiculous) thing that helped is renaming the following folder:

sudo mv /usr/local/include /usr/local/old_include

Apparently it is related to old files that homebrew installed and now broken.

Error: EACCES: permission denied

From what i can see in your logs you posted:

npm ERR!   code: 'EACCES',
npm ERR!   syscall: 'mkdir',
npm ERR!   path: '/home/rupesh/node_modules/lodash',
npm ERR!   fstream_type: 'Directory',
npm ERR!   fstream_path: '/home/rupesh/node_modules/lodash',
npm ERR!   fstream_class: 'DirWriter',

directory /home/rupesh/node_modules/ doesn't have necessary permissions to create directory so run chown -r rupesh:rupesh /home/rupesh/node_modules/ this should solve it.

How can I reduce the waiting (ttfb) time

I have met the same problem. My project is running on the local server. I checked my php code.

$db = mysqli_connect('localhost', 'root', 'root', 'smart');

I use localhost to connect to my local database. That maybe the cause of the problem which you're describing. You can modify your HOSTS file. Add the line

127.0.0.1 localhost.

Google Maps API v3 adding an InfoWindow to each marker

The add_marker still has a closure issue, cause it uses the marker variable outside the google.maps.event.addListener scope.

A better implementation would be:

function add_marker(racer_id, point, note) {
    var marker = new google.maps.Marker({map: map, position: point, clickable: true});
    marker.note = note;
    google.maps.event.addListener(marker, 'click', function() {
        info_window.content = this.note;
        info_window.open(this.getMap(), this);
    });
    return marker;
}

I also used the map from the marker, this way you don't need to pass the google map object, you probably want to use the map where the marker belongs to anyway.

asp.net validation to make sure textbox has integer values

simpally add this code:

<asp:FilteredTextBoxExtender ID="txtAltitudeMin_FilteredTextBoxExtender" runat="server" Enabled="True" TargetControlID="txtAltitudeMin" FilterType="Numbers"></asp:FilteredTextBoxExtender>

mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given in

That query is failing and returning false.

Put this after mysqli_query() to see what's going on.

if (!$check1_res) {
    printf("Error: %s\n", mysqli_error($con));
    exit();
}

For more information:

http://www.php.net/manual/en/mysqli.error.php

Failed to load JavaHL Library

For me i started getting this problem when I upgraded to java 8, and then reverted back to java 7. Upgraded again to java 8 and the problem got resolved.

SSH Key - Still asking for password and passphrase

Same problem to me and the solution was:

See this github doc to convert remote's URL from https to ssh. To check if remote's URL is ssh or https, use git remote -v. To switch from https to ssh: git remote set-url origin [email protected]:USERNAME/REPOSITORY.git @jeeYem

How to determine an interface{} value's "real" type?

There are multiple ways to get a string representation of a type. Switches can also be used with user types:

var user interface{}
user = User{name: "Eugene"}

// .(type) can only be used inside a switch
switch v := user.(type) {
case int:
    // Built-in types are possible (int, float64, string, etc.)
    fmt.Printf("Integer: %v", v)
case User:
    // User defined types work as well  
    fmt.Printf("It's a user: %s\n", user.(User).name)
}

// You can use reflection to get *reflect.rtype
userType := reflect.TypeOf(user)
fmt.Printf("%+v\n", userType)

// You can also use %T to get a string value
fmt.Printf("%T", user)

// You can even get it into a string
userTypeAsString := fmt.Sprintf("%T", user)

if userTypeAsString == "main.User" {
    fmt.Printf("\nIt's definitely a user")
}

Link to a playground: https://play.golang.org/p/VDeNDUd9uK6

Initializing IEnumerable<string> In C#

public static IEnumerable<string> GetData()
{
    yield return "1";
    yield return "2";
    yield return "3";
}

IEnumerable<string> m_oEnum = GetData();

Axios get access to response header fields

I was facing the same problem. Y did this in my "WebSecurity.java", it's about the setExposedHeaders method in the cors configuration.

@Bean
CorsConfigurationSource corsConfigurationSource() {

    CorsConfiguration configuration = new CorsConfiguration();
    configuration.setAllowCredentials(true);
    configuration.setAllowedOrigins(Arrays.asList(FRONT_END_SERVER));
    configuration.setAllowedMethods(Arrays.asList("GET", "POST", "PUT", "DELETE"));
    configuration.setAllowedHeaders(Arrays.asList("X-Requested-With","Origin","Content-Type","Accept","Authorization"));

    // This allow us to expose the headers
    configuration.setExposedHeaders(Arrays.asList("Access-Control-Allow-Headers", "Authorization, x-xsrf-token, Access-Control-Allow-Headers, Origin, Accept, X-Requested-With, " +
            "Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers"));

    UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
    source.registerCorsConfiguration("/**", configuration);
    return source;
}

I hope it works.

Visual Studio popup: "the operation could not be completed"

The error can also happen if you're in the folder in Windows Explorer or another app as you try to delete it from VS or have the file opened in another app. Windows has the habit of locking folders and files, especially on networked machines. It is possible to break the lock by using Process Explorer occasionally, but the simplest thing to do is to get out of the folder or close the file in question.

Batch program to to check if process exists

Try this:

@echo off
set run=
tasklist /fi "imagename eq notepad.exe" | find ":" > nul
if errorlevel 1 set run=yes
if "%run%"=="yes" echo notepad is running
if "%run%"=="" echo notepad is not running
pause

How to set back button text in Swift

swift 4

there is one of way to change text in backButton programmatically from current viewController:

navigationController?.navigationBar.items![0].title = "some new text"

Simple pthread! C++

This worked for me:

#include <iostream>
#include <pthread.h>
using namespace std;

void* print_message(void*) {

    cout << "Threading\n";
}

int main() {

    pthread_t t1;

    pthread_create(&t1, NULL, &print_message, NULL);
    cout << "Hello";

    // Optional.
    void* result;
    pthread_join(t1,&result);
    // :~

    return 0;
}

String.format() to format double in java

String.format("%4.3f" , x) ;

It means that we need total 4 digits in ans , of which 3 should be after decimal . And f is the format specifier of double . x means the variable for which we want to find it . Worked for me . . .

IIS7 Settings File Locations

It sounds like you're looking for applicationHost.config, which is located in C:\Windows\System32\inetsrv\config.

Yes, it's an XML file, and yes, editing the file by hand will affect the IIS config after a restart. You can think of IIS Manager as a GUI front-end for editing applicationHost.config and web.config.

What is the meaning of the prefix N in T-SQL statements and when should I use it?

It's declaring the string as nvarchar data type, rather than varchar

You may have seen Transact-SQL code that passes strings around using an N prefix. This denotes that the subsequent string is in Unicode (the N actually stands for National language character set). Which means that you are passing an NCHAR, NVARCHAR or NTEXT value, as opposed to CHAR, VARCHAR or TEXT.

To quote from Microsoft:

Prefix Unicode character string constants with the letter N. Without the N prefix, the string is converted to the default code page of the database. This default code page may not recognize certain characters.


If you want to know the difference between these two data types, see this SO post:

What is the difference between varchar and nvarchar?

Dialog with transparent background in Android

Set these style code in style

<style name="Theme.Transparent" parent="android:Theme">
    <item name="android:windowIsTranslucent">true</item>
    <item name="android:windowBackground">@android:color/transparent</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowIsFloating">true</item>
    <item name="android:backgroundDimEnabled">false</item>
</style>

And simply change false to true below line

<item name="android:backgroundDimEnabled">true</item>

It will dim your background.

How do I execute a program using Maven?

In order to execute multiple programs, I also needed a profiles section:

<profiles>
  <profile>
    <id>traverse</id>
    <activation>
      <property>
        <name>traverse</name>
      </property>
    </activation>
    <build>
      <plugins>
        <plugin>
          <groupId>org.codehaus.mojo</groupId>
          <artifactId>exec-maven-plugin</artifactId>
          <configuration>
            <executable>java</executable>
            <arguments>
              <argument>-classpath</argument>
              <argument>org.dhappy.test.NeoTraverse</argument>
            </arguments>
          </configuration>
        </plugin>
      </plugins>
    </build>
  </profile>
</profiles>

This is then executable as:

mvn exec:exec -Ptraverse

How to set editor theme in IntelliJ Idea

OK I found the problem, I was checking in the wrong place which is for the whole IDE's look and feel at File->Settings->Appearance

The correct place to change the editor appearance is through File->Settings->Editor->Colors &Fonts and then choose the scheme there. The imported settings appear there :)

Note: The theme site seems to have moved.

How to convert IPython notebooks to PDF and HTML?

The plain python version of partizanos's answer.

  • open Terminal (Linux, MacOS) or get to point where you can execute python files in Windows
  • Type the following code in a .py file (say tejas.py)
import os

[os.system("jupyter nbconvert --to pdf " + f) for f in os.listdir(".") if f.endswith("ipynb")]
  • Navigate to the folder containing the jupyter notebooks
  • Ensure that tejas.py is in the current folder. Copy it to the current folder if necessary.
  • type "python tejas.py"
  • Job done

android - listview get item view by position

workignHoursListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent,View view, int position, long id) {
        viewtype yourview=yourListViewId.getChildAt(position).findViewById(R.id.viewid);
    }
});

Collections sort(List<T>,Comparator<? super T>) method example

You probably want something like this:

Collections.sort(students, new Comparator<Student>() {
                     public int compare(Student s1, Student s2) {
                           if(s1.getName() != null && s2.getName() != null && s1.getName().comareTo(s1.getName()) != 0) {
                               return s1.getName().compareTo(s2.getName());
                           } else {
                             return s1.getAge().compareTo(s2.getAge());
                          }
                      }
);

This sorts the students first by name. If a name is missing, or two students have the same name, they are sorted by their age.

Return a value if no rows are found in Microsoft tSQL

No record matched means no record returned. There's no place for the "value" of 0 to go if no records are found. You could create a crazy UNION query to do what you want but much, much, much better simply to check the number of records in the result set.

Correct way to push into state array

In the following way we can check and update the objects

this.setState(prevState => ({
    Chart: this.state.Chart.length !== 0 ? [...prevState.Chart,data[data.length - 1]] : data
}));

What is the difference between "long", "long long", "long int", and "long long int" in C++?

This looks confusing because you are taking long as a datatype itself.

long is nothing but just the shorthand for long int when you are using it alone.

long is a modifier, you can use it with double also as long double.

long == long int.

Both of them take 4 bytes.

docker : invalid reference format

For others come to here:
If you happen to put your docker command in a file, say run.sh, check your line separator. In Linux, it should be LR, otherwise you would get the same error.

Cancel a vanilla ECMAScript 6 Promise chain

I am still working through this idea, but here is how I have implemented a cancellable Promise using setTimeout as an example.

The idea is that a promise is resolved or rejected whenever you have decided it is, so it should be a matter of deciding when you want to cancel, satisfying the criterion, and then calling the reject() function yourself.

  • First, I think there are two reasons to finish a promise early: to get it over and done with (which I have called resolve) and to cancel (which I have called reject). Of course, that’s just my feeling. Of course there is a Promise.resolve() method, but it’s in the constructor itself, and returns a dummy resolved promise. This instance resolve() method actually resolves an instantiated promise object.

  • Second, you can happily add anything you like to a newly created promise object before you return it, and so I have just added resolve() and reject() methods to make it self-contained.

  • Third, the trick is to be able to access the executor resolve and reject functions later, so I have simply stored them in a simple object from within the closure.

I think the solution is simple, and I can’t see any major problems with it.

_x000D_
_x000D_
function wait(delay) {_x000D_
  var promise;_x000D_
  var timeOut;_x000D_
  var executor={};_x000D_
  promise=new Promise(function(resolve,reject) {_x000D_
    console.log(`Started`);_x000D_
    executor={resolve,reject};  //  Store the resolve and reject methods_x000D_
    timeOut=setTimeout(function(){_x000D_
      console.log(`Timed Out`);_x000D_
      resolve();_x000D_
    },delay);_x000D_
  });_x000D_
  //  Implement your own resolve methods,_x000D_
  //  then access the stored methods_x000D_
      promise.reject=function() {_x000D_
        console.log(`Cancelled`);_x000D_
        clearTimeout(timeOut);_x000D_
        executor.reject();_x000D_
      };_x000D_
      promise.resolve=function() {_x000D_
        console.log(`Finished`);_x000D_
        clearTimeout(timeOut);_x000D_
        executor.resolve();_x000D_
      };_x000D_
  return promise;_x000D_
}_x000D_
_x000D_
var promise;_x000D_
document.querySelector('button#start').onclick=()=>{_x000D_
  promise=wait(5000);_x000D_
  promise_x000D_
  .then(()=>console.log('I have finished'))_x000D_
  .catch(()=>console.log('or not'));_x000D_
};_x000D_
document.querySelector('button#cancel').onclick=()=>{ promise.reject(); }_x000D_
document.querySelector('button#finish').onclick=()=>{ promise.resolve(); }
_x000D_
<button id="start">Start</button>_x000D_
<button id="cancel">Cancel</button>_x000D_
<button id="finish">Finish</button>
_x000D_
_x000D_
_x000D_

Twitter Bootstrap - full width navbar

Put your <nav>element out from the <div class='container-fluid'>. Ex :-

_x000D_
_x000D_
<nav>_x000D_
 ......nav content goes here_x000D_
<nav>_x000D_
_x000D_
<div class="container-fluid">_x000D_
  <div>_x000D_
   ........ other content goes here_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

error: resource android:attr/fontVariationSettings not found

I removed all the unused plugins in the pubspec.yaml and in the External Libraries to solve the problem.

Find a commit on GitHub given the commit hash

The ability to search commits has recently been added to GitHub.

To search for a hash, just enter at least the first 7 characters in the search box. Then on the results page, click the "Commits" tab to see matching commits (but only on the default branch, usually master), or the "Issues" tab to see pull requests containing the commit.

To be more explicit you can add the hash: prefix to the search, but it's not really necessary.

There is also a REST API (at the time of writing it is still in preview).

<embed> vs. <object>

You could also use the iframe method, although this is not cross browser compatible (eg. not working in chromium or android and probably others -> instead prompts to download). It works with dataURL's and normal URLS, not sure if the other examples work with dataURLS (please let me know if the other examples work with dataURLS?)

 <iframe class="page-icon preview-pane" frameborder="0" height="352" width="396" src="data:application/pdf;base64, ..DATAURLHERE!... "></iframe>

Invoke a second script with arguments from a script

Much simpler actually:

Method 1:

Invoke-Expression $scriptPath $argumentList

Method 2:

& $scriptPath $argumentList

Method 3:

$scriptPath $argumentList

If you have spaces in your scriptPath, don't forget to escape them `"$scriptPath`"

Visual Studio can't 'see' my included header files

This happened to me just now, after shutting down and restarting the computer. Eventually I realised that the architecture had somehow been changed to ARM from x64.

How do we update URL or query strings using javascript/jQuery without reloading the page?

Yes - document.location = "http://my.new.url.com"

You can also retrieve it the same way eg.

var myURL = document.location;
document.location = myURL + "?a=parameter";

The location object has a number of useful properties too:

hash            Returns the anchor portion of a URL
host            Returns the hostname and port of a URL
hostname        Returns the hostname of a URL
href            Returns the entire URL
pathname        Returns the path name of a URL
port            Returns the port number the server uses for a URL
protocol        Returns the protocol of a URL
search          Returns the query portion of a URL

EDIT: Setting the hash of the document.location shouldn't reload the page, just alter where on the page the focus is. So updating to #myId will scroll to the element with id="myId". If the id doesn't exist I believe nothing will happen? (Need to confirm on various browsers though)

EDIT2: To make it clear, not just in a comment: You can't update the whole URL with javascript without changing the page, this is a security restriction. Otherwise you could click on a link to a random page, crafted to look like gmail, and instantly change the URL to www.gmail.com and steal people's login details.
You can change the part after the domain on some browsers to cope with AJAX style things, but that's already been linked to by Osiris. What's more, you probably shouldn't do this, even if you could. The URL tells the user where he/she is on your site. If you change it without changing the page contents, it's becomes a little confusing.

Get content uri from file path in android

The accepted solution is probably the best bet for your purposes, but to actually answer the question in the subject line:

In my app, I have to get the path from URIs and get the URI from paths. The former:

/**
 * Gets the corresponding path to a file from the given content:// URI
 * @param selectedVideoUri The content:// URI to find the file path from
 * @param contentResolver The content resolver to use to perform the query.
 * @return the file path as a string
 */
private String getFilePathFromContentUri(Uri selectedVideoUri,
        ContentResolver contentResolver) {
    String filePath;
    String[] filePathColumn = {MediaColumns.DATA};

    Cursor cursor = contentResolver.query(selectedVideoUri, filePathColumn, null, null, null);
    cursor.moveToFirst();

    int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
    filePath = cursor.getString(columnIndex);
    cursor.close();
    return filePath;
}

The latter (which I do for videos, but can also be used for Audio or Files or other types of stored content by substituting MediaStore.Audio (etc) for MediaStore.Video):

/**
 * Gets the MediaStore video ID of a given file on external storage
 * @param filePath The path (on external storage) of the file to resolve the ID of
 * @param contentResolver The content resolver to use to perform the query.
 * @return the video ID as a long
 */
private long getVideoIdFromFilePath(String filePath,
        ContentResolver contentResolver) {


    long videoId;
    Log.d(TAG,"Loading file " + filePath);

            // This returns us content://media/external/videos/media (or something like that)
            // I pass in "external" because that's the MediaStore's name for the external
            // storage on my device (the other possibility is "internal")
    Uri videosUri = MediaStore.Video.Media.getContentUri("external");

    Log.d(TAG,"videosUri = " + videosUri.toString());

    String[] projection = {MediaStore.Video.VideoColumns._ID};

    // TODO This will break if we have no matching item in the MediaStore.
    Cursor cursor = contentResolver.query(videosUri, projection, MediaStore.Video.VideoColumns.DATA + " LIKE ?", new String[] { filePath }, null);
    cursor.moveToFirst();

    int columnIndex = cursor.getColumnIndex(projection[0]);
    videoId = cursor.getLong(columnIndex);

    Log.d(TAG,"Video ID is " + videoId);
    cursor.close();
    return videoId;
}

Basically, the DATA column of MediaStore (or whichever sub-section of it you're querying) stores the file path, so you use that info to look it up.

In Python, how do I determine if an object is iterable?

The isiterable func at the following code returns True if object is iterable. if it's not iterable returns False

def isiterable(object_):
    return hasattr(type(object_), "__iter__")

example

fruits = ("apple", "banana", "peach")
isiterable(fruits) # returns True

num = 345
isiterable(num) # returns False

isiterable(str) # returns False because str type is type class and it's not iterable.

hello = "hello dude !"
isiterable(hello) # returns True because as you know string objects are iterable

How to locate the Path of the current project directory in Java (IDE)?

Two ways

System.getProperty("user.dir");

or this

File currentDirFile = new File(".");
String helper = currentDirFile.getAbsolutePath();
String currentDir = helper.substring(0, helper.length() - currentDirFile.getCanonicalPath().length());//this line may need a try-catch block

The idea is to get the current folder with ".", and then fetch the absolute position to it and remove the filename from it, so from something like

/home/shark/eclipse/workspace/project/src/com/package/name/bin/Class.class

when you remove Class.class you'd get

/home/shark/eclipse/workspace/project/src/com/package/name/bin/

which is kinda what you want.

How to remove leading zeros using C#

return numberString.TrimStart('0');

How to select unique records by SQL

With the distinct keyword with single and multiple column names, you get distinct records:

SELECT DISTINCT column 1, column 2, ...
FROM table_name;

Modifying a query string without reloading the page

I want to improve Fabio's answer and create a function which adds custom key to the URL string without reloading the page.

function insertUrlParam(key, value) {
    if (history.pushState) {
        let searchParams = new URLSearchParams(window.location.search);
        searchParams.set(key, value);
        let newurl = window.location.protocol + "//" + window.location.host + window.location.pathname + '?' + searchParams.toString();
        window.history.pushState({path: newurl}, '', newurl);
    }
}

How to select records from last 24 hours using SQL?

SELECT * 
FROM table_name
WHERE table_name.the_date > DATE_SUB(CURDATE(), INTERVAL 1 DAY)

Close a MessageBox after several seconds

You could try this:

[DllImport("user32.dll", EntryPoint="FindWindow", SetLastError = true)]
static extern IntPtr FindWindowByCaption(IntPtr ZeroOnly, string lpWindowName);

[DllImport("user32.Dll")]
static extern int PostMessage(IntPtr hWnd, UInt32 msg, int wParam, int lParam);

private const UInt32 WM_CLOSE = 0x0010;

public void ShowAutoClosingMessageBox(string message, string caption)
{
    var timer = new System.Timers.Timer(5000) { AutoReset = false };
    timer.Elapsed += delegate
    {
        IntPtr hWnd = FindWindowByCaption(IntPtr.Zero, caption);
        if (hWnd.ToInt32() != 0) PostMessage(hWnd, WM_CLOSE, 0, 0);
    };
    timer.Enabled = true;
    MessageBox.Show(message, caption);
}

Making WPF applications look Metro-styled, even in Windows 7? (Window Chrome / Theming / Theme)

Based on Kapitán Mlíko's answer with source above, I would change it to use the following:

Marlett Font Example

It's a better practice to use the Marlett font rather than Path Data points for the Minimize, Restore/Maximize and Close buttons.

<StackPanel Orientation="Horizontal" HorizontalAlignment="Right" VerticalAlignment="Top" WindowChrome.IsHitTestVisibleInChrome="True" Grid.Row="0">
<Button Command="{Binding Source={x:Static SystemCommands.MinimizeWindowCommand}}" ToolTip="minimize" Style="{StaticResource WindowButtonStyle}">
    <Button.Content>
        <Grid Width="30" Height="25">
            <TextBlock Text="0" FontFamily="Marlett" FontSize="14" VerticalAlignment="Center" HorizontalAlignment="Center" Padding="3.5,0,0,3" />
        </Grid>
    </Button.Content>
</Button>
<Grid Margin="1,0,1,0">
    <Button x:Name="Restore" Command="{Binding Source={x:Static SystemCommands.RestoreWindowCommand}}" ToolTip="restore" Visibility="Collapsed" Style="{StaticResource WindowButtonStyle}">
        <Button.Content>
            <Grid Width="30" Height="25" UseLayoutRounding="True">
                <TextBlock Text="2" FontFamily="Marlett" FontSize="14" VerticalAlignment="Center" HorizontalAlignment="Center" Padding="2,0,0,1" />
            </Grid>
        </Button.Content>
    </Button>
    <Button x:Name="Maximize" Command="{Binding Source={x:Static SystemCommands.MaximizeWindowCommand}}" ToolTip="maximize" Style="{StaticResource WindowButtonStyle}">
        <Button.Content>
            <Grid Width="31" Height="25">
                <TextBlock Text="1" FontFamily="Marlett" FontSize="14" VerticalAlignment="Center" HorizontalAlignment="Center" Padding="2,0,0,1" />
            </Grid>
        </Button.Content>
    </Button>
</Grid>
<Button Command="{Binding Source={x:Static SystemCommands.CloseWindowCommand}}" ToolTip="close"  Style="{StaticResource WindowButtonStyle}">
    <Button.Content>
        <Grid Width="30" Height="25">
            <TextBlock Text="r" FontFamily="Marlett" FontSize="14" VerticalAlignment="Center" HorizontalAlignment="Center" Padding="0,0,0,1" />
        </Grid>
    </Button.Content>
</Button>

Setting a property with an EventTrigger

Just create your own action.

namespace WpfUtil
{
    using System.Reflection;
    using System.Windows;
    using System.Windows.Interactivity;


    /// <summary>
    /// Sets the designated property to the supplied value. TargetObject
    /// optionally designates the object on which to set the property. If
    /// TargetObject is not supplied then the property is set on the object
    /// to which the trigger is attached.
    /// </summary>
    public class SetPropertyAction : TriggerAction<FrameworkElement>
    {
        // PropertyName DependencyProperty.

        /// <summary>
        /// The property to be executed in response to the trigger.
        /// </summary>
        public string PropertyName
        {
            get { return (string)GetValue(PropertyNameProperty); }
            set { SetValue(PropertyNameProperty, value); }
        }

        public static readonly DependencyProperty PropertyNameProperty
            = DependencyProperty.Register("PropertyName", typeof(string),
            typeof(SetPropertyAction));


        // PropertyValue DependencyProperty.

        /// <summary>
        /// The value to set the property to.
        /// </summary>
        public object PropertyValue
        {
            get { return GetValue(PropertyValueProperty); }
            set { SetValue(PropertyValueProperty, value); }
        }

        public static readonly DependencyProperty PropertyValueProperty
            = DependencyProperty.Register("PropertyValue", typeof(object),
            typeof(SetPropertyAction));


        // TargetObject DependencyProperty.

        /// <summary>
        /// Specifies the object upon which to set the property.
        /// </summary>
        public object TargetObject
        {
            get { return GetValue(TargetObjectProperty); }
            set { SetValue(TargetObjectProperty, value); }
        }

        public static readonly DependencyProperty TargetObjectProperty
            = DependencyProperty.Register("TargetObject", typeof(object),
            typeof(SetPropertyAction));


        // Private Implementation.

        protected override void Invoke(object parameter)
        {
            object target = TargetObject ?? AssociatedObject;
            PropertyInfo propertyInfo = target.GetType().GetProperty(
                PropertyName,
                BindingFlags.Instance|BindingFlags.Public
                |BindingFlags.NonPublic|BindingFlags.InvokeMethod);

            propertyInfo.SetValue(target, PropertyValue);
        }
    }
}

In this case I'm binding to a property called DialogResult on my viewmodel.

<Grid>

    <Button>
        <i:Interaction.Triggers>
            <i:EventTrigger EventName="Click">
                <wpf:SetPropertyAction PropertyName="DialogResult" TargetObject="{Binding}"
                                       PropertyValue="{x:Static mvvm:DialogResult.Cancel}"/>
            </i:EventTrigger>
        </i:Interaction.Triggers>
        Cancel
    </Button>

</Grid>

How can I show the table structure in SQL Server query?

I was trying 'DESC table_name' but then this worked for me in psql:

select * 
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME='table_name'; 

How to enumerate a range of numbers starting at 1

As you already mentioned, this is straightforward to do in Python 2.6 or newer:

enumerate(range(2000, 2005), 1)

Python 2.5 and older do not support the start parameter so instead you could create two range objects and zip them:

r = xrange(2000, 2005)
r2 = xrange(1, len(r) + 1)
h = zip(r2, r)
print h

Result:

[(1, 2000), (2, 2001), (3, 2002), (4, 2003), (5, 2004)]

If you want to create a generator instead of a list then you can use izip instead.

How to return a boolean method in java?

public boolean verifyPwd(){
        if (!(pword.equals(pwdRetypePwd.getText()))){
                  txtaError.setEditable(true);
                  txtaError.setText("*Password didn't match!");
                  txtaError.setForeground(Color.red);
                  txtaError.setEditable(false);
                  return false;
           }
        else {
            addNewUser();
            return true;
        }
}

How do I get the coordinates of a mouse click on a canvas element?

I made a full demostration that works in every browser with the full source code of the solution of this problem: Coordinates of a mouse click on Canvas in Javascript. To try the demo, copy the code and paste it into a text editor. Then save it as example.html and, finally, open the file with a browser.

IF EXISTS in T-SQL

Yes it stops execution so this is generally preferable to HAVING COUNT(*) > 0 which often won't.

With EXISTS if you look at the execution plan you will see that the actual number of rows coming out of table1 will not be more than 1 irrespective of number of matching records.

In some circumstances SQL Server can convert the tree for the COUNT query to the same as the one for EXISTS during the simplification phase (with a semi join and no aggregate operator in sight) an example of that is discussed in the comments here.

For more complicated sub trees than shown in the question you may occasionally find the COUNT performs better than EXISTS however. Because the semi join needs only retrieve one row from the sub tree this can encourage a plan with nested loops for that part of the tree - which may not work out optimal in practice.

Powershell: How can I stop errors from being displayed in a script?

You're way off track here.

You already have a nice, big error message. Why on Earth would you want to write code that checks $? explicitly after every single command? This is enormously cumbersome and error prone. The correct solution is stop checking $?.

Instead, use PowerShell's built in mechanism to blow up for you. You enable it by setting the error preference to the highest level:

$ErrorActionPreference = 'Stop'

I put this at the top of every single script I ever write, and now I don't have to check $?. This makes my code vastly simpler and more reliable.

If you run into situations where you really need to disable this behavior, you can either catch the error or pass a setting to a particular function using the common -ErrorAction. In your case, you probably want your process to stop on the first error, catch the error, and then log it.

Do note that this doesn't handle the case when external executables fail (exit code nonzero, conventionally), so you do still need to check $LASTEXITCODE if you invoke any. Despite this limitation, the setting still saves a lot of code and effort.

Additional reliability

You might also want to consider using strict mode:

Set-StrictMode -Version Latest

This prevents PowerShell from silently proceeding when you use a non-existent variable and in other weird situations. (See the -Version parameter for details about what it restricts.)

Combining these two settings makes PowerShell much more of fail-fast language, which makes programming in it vastly easier.

Fully backup a git repo?

Whats about just make a clone of it?

git clone --mirror other/repo.git

Every repository is a backup of its remote.

Print the data in ResultSet along with column names

1) Instead of PreparedStatement use Statement

2) After executing query in ResultSet, extract values with the help of rs.getString() as :

Statement st=cn.createStatement();
ResultSet rs=st.executeQuery(sql);
while(rs.next())
{
    rs.getString(1); //or rs.getString("column name");
}

How to get filename without extension from file path in Ruby

Try File.basename

Returns the last component of the filename given in file_name, which must be formed using forward slashes (``/’’) regardless of the separator used on the local file system. If suffix is given and present at the end of file_name, it is removed.

File.basename("/home/gumby/work/ruby.rb")          #=> "ruby.rb"
File.basename("/home/gumby/work/ruby.rb", ".rb")   #=> "ruby"

In your case:

File.basename("C:\\projects\\blah.dll", ".dll")  #=> "blah"

PSQLException: current transaction is aborted, commands ignored until end of transaction block

You need to rollback. The JDBC Postgres driver is pretty bad. But if you want to keep your transaction, and just rollback that error, you can use savepoints:

try {
_stmt = connection.createStatement();
_savePoint = connection.setSavepoint("sp01");
_result = _stmt.executeUpdate(sentence) > 0;
} catch (Exception e){
 if (_savePoint!=null){
 connection.rollback(_savePoint);
}
}

Read more here:

http://www.postgresql.org/docs/8.1/static/sql-savepoint.html

Disable SSL fallback and use only TLS for outbound connections in .NET? (Poodle mitigation)

@watson

On windows forms it is available, at the top of the class put

  static void Main(string[] args)
    {
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
       //other stuff here
    }

since windows is single threaded, its all you need, in the event its a service you need to put it right above the call to the service (since there is no telling what thread you'll be on).

using System.Security.Principal 

is also needed.

install cx_oracle for python

Alternatively you can install the cx_Oracle module without the PIP using the following steps

  1. Download the source from here https://pypi.python.org/pypi/cx_Oracle [cx_Oracle-6.1.tar.gz ]
  2. Extract the tar using the following commands (Linux)

    gunzip cx_Oracle-6.1.tar.gz

    tar -xf cx_Oracle-6.1.tar

  3. cd cx_Oracle-6.1

  4. Build the module

    python setup.py build

  5. Install the module

    python setup.py install

Center div on the middle of screen

2018: CSS3

div{
    position: absolute;
    top: 50%;
    left: 50%;
    margin-right: -50%;
    transform: translate(-50%, -50%);
}

This is even shorter. For more information see this: CSS: Centering Things

#1273 - Unknown collation: 'utf8mb4_unicode_ci' cPanel

The easiest way to do is export your database to .sql, open it on Notepad++ and "Search and Replace" the utf8mb4_unicode_ci to utf8_unicode_ci and also replace utf8mb4 to utf8. Also don't forget to change the database collation to utf8_unicode_ci (Operations > Collation).

How to remove element from array in forEach loop?

The following will give you all the elements which is not equal to your special characters!

review = jQuery.grep( review, function ( value ) {
    return ( value !== '\u2022 \u2022 \u2022' );
} );

Pythonic way to add datetime.date and datetime.time objects

It's in the python docs.

import datetime
datetime.datetime.combine(datetime.date(2011, 1, 1), 
                          datetime.time(10, 23))

returns

datetime.datetime(2011, 1, 1, 10, 23)

How to make an Android Spinner with initial text "Select One"?

if you are facing this issue when your items are populates from database-cursor,

the simplest solution that I found in this SO answer:

use UNION in your cursor adapter query and add the additional item with id= -1 to the query result, without really adding it to the DB:

something like:

db.rawQuery("SELECT iWorkerId as _id, nvLastName as name  FROM  Worker
w  UNION  SELECT -1 as _id , '' as name",null);

if the item selected is -1, then it's the default value. Otherwise it's a record from the table.

Detect Android phone via Javascript / jQuery

js version, catches iPad too:

var is_mobile = /mobile|android/i.test (navigator.userAgent);

Create code first, many to many, with additional fields in association table

The code provided by this answer is right, but incomplete, I've tested it. There are missing properties in "UserEmail" class:

    public UserTest UserTest { get; set; }
    public EmailTest EmailTest { get; set; }

I post the code I've tested if someone is interested. Regards

using System.Data.Entity;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Web;

#region example2
public class UserTest
{
    public int UserTestID { get; set; }
    public string UserTestname { get; set; }
    public string Password { get; set; }

    public ICollection<UserTestEmailTest> UserTestEmailTests { get; set; }

    public static void DoSomeTest(ApplicationDbContext context)
    {

        for (int i = 0; i < 5; i++)
        {
            var user = context.UserTest.Add(new UserTest() { UserTestname = "Test" + i });
            var address = context.EmailTest.Add(new EmailTest() { Address = "address@" + i });
        }
        context.SaveChanges();

        foreach (var user in context.UserTest.Include(t => t.UserTestEmailTests))
        {
            foreach (var address in context.EmailTest)
            {
                user.UserTestEmailTests.Add(new UserTestEmailTest() { UserTest = user, EmailTest = address, n1 = user.UserTestID, n2 = address.EmailTestID });
            }
        }
        context.SaveChanges();
    }
}

public class EmailTest
{
    public int EmailTestID { get; set; }
    public string Address { get; set; }

    public ICollection<UserTestEmailTest> UserTestEmailTests { get; set; }
}

public class UserTestEmailTest
{
    public int UserTestID { get; set; }
    public UserTest UserTest { get; set; }
    public int EmailTestID { get; set; }
    public EmailTest EmailTest { get; set; }
    public int n1 { get; set; }
    public int n2 { get; set; }


    //Call this code from ApplicationDbContext.ConfigureMapping
    //and add this lines as well:
    //public System.Data.Entity.DbSet<yournamespace.UserTest> UserTest { get; set; }
    //public System.Data.Entity.DbSet<yournamespace.EmailTest> EmailTest { get; set; }
    internal static void RelateFluent(System.Data.Entity.DbModelBuilder builder)
    {
        // Primary keys
        builder.Entity<UserTest>().HasKey(q => q.UserTestID);
        builder.Entity<EmailTest>().HasKey(q => q.EmailTestID);

        builder.Entity<UserTestEmailTest>().HasKey(q =>
            new
            {
                q.UserTestID,
                q.EmailTestID
            });

        // Relationships
        builder.Entity<UserTestEmailTest>()
            .HasRequired(t => t.EmailTest)
            .WithMany(t => t.UserTestEmailTests)
            .HasForeignKey(t => t.EmailTestID);

        builder.Entity<UserTestEmailTest>()
            .HasRequired(t => t.UserTest)
            .WithMany(t => t.UserTestEmailTests)
            .HasForeignKey(t => t.UserTestID);
    }
}
#endregion

How to remove class from all elements jquery

This just removes the highlight class from everything that has the edgetoedge class:

$(".edgetoedge").removeClass("highlight");

I think you want this:

$(".edgetoedge .highlight").removeClass("highlight");

The .edgetoedge .highlight selector will choose everything that is a child of something with the edgetoedge class and has the highlight class.

Is module __file__ attribute absolute or relative?

__file__ is absolute since Python 3.4, except when executing a script directly using a relative path:

Module __file__ attributes (and related values) should now always contain absolute paths by default, with the sole exception of __main__.__file__ when a script has been executed directly using a relative path. (Contributed by Brett Cannon in bpo-18416.)

Not sure if it resolves symlinks though.

Example of passing a relative path:

$ python script.py

How to delete columns that contain ONLY NAs?

Here is a dplyr solution:

df %>% select_if(~sum(!is.na(.)) > 0)

Update: The summarise_if() function is superseded as of dplyr 1.0. Here are two other solutions that use the where() tidyselect function:

df %>% 
  select(
    where(
      ~sum(!is.na(.x)) > 0
    )
  )
df %>% 
  select(
    where(
      ~!all(is.na(.x))
    )
  )

How to get first/top row of the table in Sqlite via Sql Query

LIMIT 1 is what you want. Just keep in mind this returns the first record in the result set regardless of order (unless you specify an order clause in an outer query).

What is the difference between onBlur and onChange attribute in HTML?

The onBlur event is fired when you have moved away from an object without necessarily having changed its value.

The onChange event is only called when you have changed the value of the field and it loses focus.

You might want to take a look at quirksmode's intro to events. This is a great place to get info on what's going on in your browser when you interact with it. His book is good too.

What is the difference between %g and %f in C?

E = exponent expression, simply means power(10, n) or 10 ^ n

F = fraction expression, default 6 digits precision

G = gerneral expression, somehow smart to show the number in a concise way (but really?)

See the below example,

The code

void main(int argc, char* argv[])  
{  
        double a = 4.5;
        printf("=>>>> below is the example for printf 4.5\n");
        printf("%%e %e\n",a);
        printf("%%f %f\n",a);
        printf("%%g %g\n",a);
        printf("%%E %E\n",a);
        printf("%%F %F\n",a);
        printf("%%G %G\n",a);
          
        double b = 1.79e308;
        printf("=>>>> below is the exbmple for printf 1.79*10^308\n");
        printf("%%e %e\n",b);
        printf("%%f %f\n",b);
        printf("%%g %g\n",b);
        printf("%%E %E\n",b);
        printf("%%F %F\n",b);
        printf("%%G %G\n",b);

        double d = 2.25074e-308;
        printf("=>>>> below is the example for printf 2.25074*10^-308\n");
        printf("%%e %e\n",d);
        printf("%%f %f\n",d);
        printf("%%g %g\n",d);
        printf("%%E %E\n",d);
        printf("%%F %F\n",d);
        printf("%%G %G\n",d);
}  

The output

=>>>> below is the example for printf 4.5
%e 4.500000e+00
%f 4.500000
%g 4.5
%E 4.500000E+00
%F 4.500000
%G 4.5
=>>>> below is the exbmple for printf 1.79*10^308
%e 1.790000e+308
%f 178999999999999996376899522972626047077637637819240219954027593177370961667659291027329061638406108931437333529420935752785895444161234074984843178962619172326295244262722141766382622299223626438470088150218987997954747866198184686628013966119769261150988554952970462018533787926725176560021258785656871583744.000000
%g 1.79e+308
%E 1.790000E+308
%F 178999999999999996376899522972626047077637637819240219954027593177370961667659291027329061638406108931437333529420935752785895444161234074984843178962619172326295244262722141766382622299223626438470088150218987997954747866198184686628013966119769261150988554952970462018533787926725176560021258785656871583744.000000
%G 1.79E+308
=>>>> below is the example for printf 2.25074*10^-308
%e 2.250740e-308
%f 0.000000
%g 2.25074e-308
%E 2.250740E-308
%F 0.000000
%G 2.25074E-308

How to Delete a topic in apache kafka

Deletion of a topic has been supported since 0.8.2.x version. You have to enable topic deletion (setting delete.topic.enable to true) on all brokers first.

Note: Ever since 1.0.x, the functionality being stable, delete.topic.enable is by default true.

Follow this step by step process for manual deletion of topics

  1. Stop Kafka server
  2. Delete the topic directory, on each broker (as defined in the logs.dirs and log.dir properties) with rm -rf command
  3. Connect to Zookeeper instance: zookeeper-shell.sh host:port
  4. From within the Zookeeper instance:
    1. List the topics using: ls /brokers/topics
    2. Remove the topic folder from ZooKeeper using: rmr /brokers/topics/yourtopic
    3. Exit the Zookeeper instance (Ctrl+C)
  5. Restart Kafka server
  6. Confirm if it was deleted or not by using this command kafka-topics.sh --list --zookeeper host:port

How can I add a class attribute to an HTML element generated by MVC's HTML Helpers?

In order to create an anonymous type (or any type) with a property that has a reserved keyword as its name in C#, you can prepend the property name with an at sign, @:

Html.BeginForm("Foo", "Bar", FormMethod.Post, new { @class = "myclass"})

For VB.NET this syntax would be accomplished using the dot, ., which in that language is default syntax for all anonymous types:

Html.BeginForm("Foo", "Bar", FormMethod.Post, new with { .class = "myclass" })

Access 2010 VBA query a table and iterate through results

I know some things have changed in AC 2010. However, the old-fashioned ADODB is, as far as I know, the best way to go in VBA. An Example:

Dim cn As ADODB.Connection
Dim cmd As ADODB.Command
Dim prm As ADODB.Parameter
Dim rs As ADODB.Recordset
Dim colReturn As New Collection

Dim SQL As String
SQL = _
    "SELECT c.ClientID, c.LastName, c.FirstName, c.MI, c.DOB, c.SSN, " & _
    "c.RaceID, c.EthnicityID, c.GenderID, c.Deleted, c.RecordDate " & _
    "FROM tblClient AS c " & _
    "WHERE c.ClientID = @ClientID"

Set cn = New ADODB.Connection
Set cmd = New ADODB.Command

With cn
    .Provider = DataConnection.MyADOProvider
    .ConnectionString = DataConnection.MyADOConnectionString
    .Open
End With

With cmd
    .CommandText = SQL
    .ActiveConnection = cn
    Set prm = .CreateParameter("@ClientID", adInteger, adParamInput, , mlngClientID)
    .Parameters.Append prm
End With

Set rs = cmd.Execute

With rs
    If Not .EOF Then
        Do Until .EOF
            mstrLastName = Nz(!LastName, "")
            mstrFirstName = Nz(!FirstName, "")
            mstrMI = Nz(!MI, "")
            mdDOB = !DOB
            mstrSSN = Nz(!SSN, "")
            mlngRaceID = Nz(!RaceID, -1)
            mlngEthnicityID = Nz(!EthnicityID, -1)
            mlngGenderID = Nz(!GenderID, -1)
            mbooDeleted = Deleted
            mdRecordDate = Nz(!RecordDate, "")

            .MoveNext
        Loop
    End If
    .Close
End With

cn.Close

Set rs = Nothing
Set cn = Nothing

How to determine SSL cert expiration date from a PEM encoded certificate?

Here's a bash function which checks all your servers, assuming you're using DNS round-robin. Note that this requires GNU date and won't work on Mac OS

function check_certs () {
  if [ -z "$1" ]
  then
    echo "domain name missing"
    exit 1
  fi
  name="$1"
  shift

  now_epoch=$( date +%s )

  dig +noall +answer $name | while read _ _ _ _ ip;
  do
    echo -n "$ip:"
    expiry_date=$( echo | openssl s_client -showcerts -servername $name -connect $ip:443 2>/dev/null | openssl x509 -inform pem -noout -enddate | cut -d "=" -f 2 )
    echo -n " $expiry_date";
    expiry_epoch=$( date -d "$expiry_date" +%s )
    expiry_days="$(( ($expiry_epoch - $now_epoch) / (3600 * 24) ))"
    echo "    $expiry_days days"
  done
}

Output example:

$ check_certs stackoverflow.com
151.101.1.69: Aug 14 12:00:00 2019 GMT    603 days
151.101.65.69: Aug 14 12:00:00 2019 GMT    603 days
151.101.129.69: Aug 14 12:00:00 2019 GMT    603 days
151.101.193.69: Aug 14 12:00:00 2019 GMT    603 days

Why is it string.join(list) instead of list.join(string)?

Think of it as the natural orthogonal operation to split.

I understand why it is applicable to anything iterable and so can't easily be implemented just on list.

For readability, I'd like to see it in the language but I don't think that is actually feasible - if iterability were an interface then it could be added to the interface but it is just a convention and so there's no central way to add it to the set of things which are iterable.

How can I convert an HTML table to CSV?

This method is not really a library OR a program, but for ad hoc conversions you can

  • put the HTML for a table in a text file called something.xls
  • open it with a spreadsheet
  • save it as CSV.

I know this works with Excel, and I believe I've done it with the OpenOffice spreadsheet.

But you probably would prefer a Perl or Ruby script...

what does the __file__ variable mean/do?

When a module is loaded from a file in Python, __file__ is set to its path. You can then use that with other functions to find the directory that the file is located in.

Taking your examples one at a time:

A = os.path.join(os.path.dirname(__file__), '..')
# A is the parent directory of the directory where program resides.

B = os.path.dirname(os.path.realpath(__file__))
# B is the canonicalised (?) directory where the program resides.

C = os.path.abspath(os.path.dirname(__file__))
# C is the absolute path of the directory where the program resides.

You can see the various values returned from these here:

import os
print(__file__)
print(os.path.join(os.path.dirname(__file__), '..'))
print(os.path.dirname(os.path.realpath(__file__)))
print(os.path.abspath(os.path.dirname(__file__)))

and make sure you run it from different locations (such as ./text.py, ~/python/text.py and so forth) to see what difference that makes.


I just want to address some confusion first. __file__ is not a wildcard it is an attribute. Double underscore attributes and methods are considered to be "special" by convention and serve a special purpose.

http://docs.python.org/reference/datamodel.html shows many of the special methods and attributes, if not all of them.

In this case __file__ is an attribute of a module (a module object). In Python a .py file is a module. So import amodule will have an attribute of __file__ which means different things under difference circumstances.

Taken from the docs:

__file__ is the pathname of the file from which the module was loaded, if it was loaded from a file. The __file__ attribute is not present for C modules that are statically linked into the interpreter; for extension modules loaded dynamically from a shared library, it is the pathname of the shared library file.

In your case the module is accessing it's own __file__ attribute in the global namespace.

To see this in action try:

# file: test.py

print globals()
print __file__

And run:

python test.py

{'__builtins__': <module '__builtin__' (built-in)>, '__name__': '__main__', '__file__':
 'test_print__file__.py', '__doc__': None, '__package__': None}
test_print__file__.py

Different color for each bar in a bar chart; ChartJS

Generate random colors;

function getRandomColor() {
    var letters = '0123456789ABCDEF'.split('');
    var color = '#';
    for (var i = 0; i < 6; i++) {
        color += letters[Math.floor(Math.random() * 16)];
    }
    return color;
}

and call it for each record;

function getRandomColorEachEmployee(count) {
    var data =[];
    for (var i = 0; i < count; i++) {
        data.push(getRandomColor());
    }
    return data;
}

finally set colors;

var data = {
    labels: jsonData.employees, // your labels
    datasets: [{
        data: jsonData.approvedRatios, // your data
        backgroundColor: getRandomColorEachEmployee(jsonData.employees.length)
    }]
};

VirtualBox error "Failed to open a session for the virtual machine"

I had the same issue, I tried editing the VM but it wasn't letting me save it. So I tried the following:

  1. Tried editing the VM to change RAM/CPU etc, but it wasn't letting me save it
  2. Deleted the vm (not the data) and tried adding it again, didn't fix it
  3. Tried moving the vbox file to another directory and import it, but it didn't let me move the vbox file so I realized there's a virtualbox process running that's holding a lock on it. So I killed that process and started it again and my VM booted

jquery, domain, get URL

jQuery is not needed, use simple javascript:

document.domain

MySQL convert date string to Unix timestamp

You will certainly have to use both STR_TO_DATE to convert your date to a MySQL standard date format, and UNIX_TIMESTAMP to get the timestamp from it.

Given the format of your date, something like

UNIX_TIMESTAMP(STR_TO_DATE(Sales.SalesDate, '%M %e %Y %h:%i%p'))

Will gives you a valid timestamp. Look the STR_TO_DATE documentation to have more information on the format string.

Plotting multiple time series on the same plot using ggplot()

I know this is old but it is still relevant. You can take advantage of reshape2::melt to change the dataframe into a more friendly structure for ggplot2.

Advantages:

  • allows you plot any number of lines
  • each line with a different color
  • adds a legend for each line
  • with only one call to ggplot/geom_line

Disadvantage:

  • an extra package(reshape2) required
  • melting is not so intuitive at first

For example:

jobsAFAM1 <- data.frame(
  data_date = seq.Date(from = as.Date('2017-01-01'),by = 'day', length.out = 100),
  Percent.Change = runif(5,1,100)
)

jobsAFAM2 <- data.frame(
  data_date = seq.Date(from = as.Date('2017-01-01'),by = 'day', length.out = 100),
  Percent.Change = runif(5,1,100)
)

jobsAFAM <- merge(jobsAFAM1, jobsAFAM2, by="data_date")

jobsAFAMMelted <- reshape2::melt(jobsAFAM, id.var='data_date')

ggplot(jobsAFAMMelted, aes(x=data_date, y=value, col=variable)) + geom_line()

enter image description here

Removing spaces from a variable input using PowerShell 4.0

You also have the Trim, TrimEnd and TrimStart methods of the System.String class. The trim method will strip whitespace (with a couple of Unicode quirks) from the leading and trailing portion of the string while allowing you to optionally specify the characters to remove.

#Note there are spaces at the beginning and end
Write-Host " ! This is a test string !%^ "
 ! This is a test string !%^
#Strips standard whitespace
Write-Host " ! This is a test string !%^ ".Trim()
! This is a test string !%^
#Strips the characters I specified
Write-Host " ! This is a test string !%^ ".Trim('!',' ')
This is a test string !%^
#Now removing ^ as well
Write-Host " ! This is a test string !%^ ".Trim('!',' ','^')
This is a test string !%
Write-Host " ! This is a test string !%^ ".Trim('!',' ','^','%')
This is a test string
#Powershell even casts strings to character arrays for you
Write-Host " ! This is a test string !%^ ".Trim('! ^%')
This is a test string

TrimStart and TrimEnd work the same way just only trimming the start or end of the string.

How to change the cursor into a hand when a user hovers over a list item?

Simply just do something like this:

li { 
  cursor: pointer;
}

I apply it on your code to see how it works:

_x000D_
_x000D_
li {_x000D_
  cursor: pointer;_x000D_
}
_x000D_
<ul>_x000D_
  <li>foo</li>_x000D_
  <li>goo</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

Note: Also DO not forget you can have any hand cursor with customised cursor, you can create fav hand icon like this one for example:

_x000D_
_x000D_
div {_x000D_
  display: block;_x000D_
  width: 400px;_x000D_
  height: 400px;_x000D_
  background: red;_x000D_
  cursor: url(http://findicons.com/files/icons/1840/free_style/128/hand.png) 4 12, auto;_x000D_
}
_x000D_
<div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to remove special characters from a string?

Try replaceAll() method of the String class.

BTW here is the method, return type and parameters.

public String replaceAll(String regex,
                         String replacement)

Example:

String str = "Hello +-^ my + - friends ^ ^^-- ^^^ +!";
str = str.replaceAll("[-+^]*", "");

It should remove all the {'^', '+', '-'} chars that you wanted to remove!

How to give ASP.NET access to a private key in a certificate in the certificate store?

In Certificates Panel, right click some certificate -> All tasks -> Manage private key -> Add IIS_IUSRS User with full control

In my case, I didnt't need to install my certificate with "Allow private key to be exported" option checked, like said in other answers.

How to calculate difference between two dates in oracle 11g SQL

You can use this:

SET FEEDBACK OFF;
SET SERVEROUTPUT ON;

DECLARE
  V_START_DATE  CHAR(17) := '28/03/16 17:20:00';
  V_END_DATE    CHAR(17) := '30/03/16 17:50:10';
  V_DATE_DIFF   VARCHAR2(17);

BEGIN

SELECT
  (TO_NUMBER( SUBSTR(NUMTODSINTERVAL(TO_DATE(V_END_DATE , 'DD/MM/YY HH24:MI:SS') - TO_DATE(V_START_DATE, 'DD/MM/YY HH24:MI:SS'), 'DAY'), 02, 9)) * 24) +
  (TO_NUMBER( SUBSTR(NUMTODSINTERVAL(TO_DATE(V_END_DATE , 'DD/MM/YY HH24:MI:SS') - TO_DATE(V_START_DATE, 'DD/MM/YY HH24:MI:SS'), 'DAY'), 12, 2)))  || 
              SUBSTR(NUMTODSINTERVAL(TO_DATE(V_END_DATE , 'DD/MM/YY HH24:MI:SS') - TO_DATE(V_START_DATE, 'DD/MM/YY HH24:MI:SS'), 'DAY'), 14, 6) AS "HH24:MI:SS"
  INTO V_DATE_DIFF
FROM 
  DUAL;

DBMS_OUTPUT.PUT_LINE(V_DATE_DIFF);
END;

Convert to binary and keep leading zeros in Python

I am using

bin(1)[2:].zfill(8)

will print

'00000001'

How do I trim() a string in angularjs?

use trim() method of javascript after all angularjs is also a javascript framework and it is not necessary to put $ to apply trim()

for example

var x="hello world";
x=x.trim()

How can I increment a char?

Check this: USING FOR LOOP

for a in range(5):
    x='A'
    val=chr(ord(x) + a)
    print(val)

LOOP OUTPUT: A B C D E

How to create a sticky footer that plays well with Bootstrap 3

What worked for me was adding the position relative to the html tag.

html {
  min-height:100%;
  position:relative;
}
body {
  margin-bottom:60px;
}
footer {
  position:absolute;
  bottom:0;
  height:60px;
}

Android - Set text to TextView

I had a similar problem. It turns out I had two TextView objects with the same ID. They were in different view files and so Eclipse did not give me an error. Try to rename your id in the TextView and see if that does not fix your problem.

diff current working copy of a file with another branch's committed copy

git diff mybranch master -- file

should also work

How should I escape commas and speech marks in CSV files so they work in Excel?

According to Yashu's instructions, I wrote the following function (it's PL/SQL code, but it should be easily adaptable to any other language).

FUNCTION field(str IN VARCHAR2) RETURN VARCHAR2 IS
    C_NEWLINE CONSTANT CHAR(1) := '
'; -- newline is intentional

    v_aux VARCHAR2(32000);
    v_has_double_quotes BOOLEAN;
    v_has_comma BOOLEAN;
    v_has_newline BOOLEAN;
BEGIN
    v_has_double_quotes := instr(str, '"') > 0;
    v_has_comma := instr(str,',') > 0;
    v_has_newline := instr(str, C_NEWLINE) > 0;

    IF v_has_double_quotes OR v_has_comma OR v_has_newline THEN
        IF v_has_double_quotes THEN
            v_aux := replace(str,'"','""');
        ELSE
            v_aux := str;
        END IF;
        return '"'||v_aux||'"';
    ELSE
        return str;
    END IF;
END;

How do you rebase the current branch's changes on top of changes being merged in?

Another way to look at it is to consider git rebase master as:

Rebase the current branch on top of master

Here , 'master' is the upstream branch, and that explain why, during a rebase, ours and theirs are reversed.

How do you revert to a specific tag in Git?

Use git reset:

git reset --hard "Version 1.0 Revision 1.5"

(assuming that the specified string is the tag).

Put spacing between divs in a horizontal row?

Quite a few ways to apprach this problem.

Use the box-sizing css3 property and simulate the margins with borders.

http://jsfiddle.net/Z7mFr/1/

div.inside {
 width: 25%;
 float:left;
 border-right: 5px solid grey;
 background-color: blue;
 box-sizing:border-box;
 -moz-box-sizing:border-box; /* Firefox */
 -webkit-box-sizing:border-box; /* Safari */
}

<div style="width:100%; height: 200px; background-color: grey;">
 <div class="inside">A</div>
 <div class="inside">B</div>
 <div class="inside">C</div>
 <div class="inside">D</div>
</div>

Reduce the percentage of your elements widths and add some margin-right.

http://jsfiddle.net/mJfz3/

.outer {
 width:100%;
 background:#999;
 overflow:auto;
}

.inside {
 float:left;
 width:24%;
 margin-right:1%;
 background:#333;
}

How does DateTime.Now.Ticks exactly work?

I had a similar problem.

I would also look at this answer: Is there a high resolution (microsecond, nanosecond) DateTime object available for the CLR?.

About half-way down is an answer by "Robert P" with some extension functions I found useful.

JavaScript, getting value of a td with id name

If by 'td value' you mean text inside of td, then:

document.getElementById('td-id').innerHTML

How can I check for an empty/undefined/null string in JavaScript?

Very generic "All-In-One" Function (not recommended though):

function is_empty(x)
{
    return (                                                           //don't put newline after return
        (typeof x == 'undefined')
              ||
        (x == null)
              ||
        (x == false)        //same as: !x
              ||
        (x.length == 0)
              ||
        (x == 0)            // note this line, you might not need this. 
              ||
        (x == "")
              ||
        (x.replace(/\s/g,"") == "")
              ||
        (!/[^\s]/.test(x))
              ||
        (/^\s*$/.test(x))
    );
}

However, I don't recommend to use that, because your target variable should be of specific type (i.e. string, or numeric, or object?), so apply the checks that are relative to that variable.

Check if a user has scrolled to the bottom

Here's a fairly simple approach

const didScrollToBottom = elm.scrollTop + elm.clientHeight == elm.scrollHeight

Example

elm.onscroll = function() {
    if(elm.scrollTop + elm.clientHeight == elm.scrollHeight) {
        // User has scrolled to the bottom of the element
    }
}

Where elm is an element retrieved from i.e document.getElementById.

What is the difference/usage of homebrew, macports or other package installation tools?

Currently, Macports has many more packages (~18.6 K) than there are Homebrew formulae (~3.1K), owing to its maturity. Homebrew is slowly catching up though.

Macport packages tend to be maintained by a single person.

Macports can keep multiple versions of packages around, and you can enable or disable them to test things out. Sometimes this list can get corrupted and you have to manually edit it to get things back in order, although this is not too hard.

Both package managers will ask to be regularly updated. This can take some time.

Note: you can have both package managers on your system! It is not one or the other. Brew might complain but Macports won't.

Also, if you are dealing with python or ruby packages, use a virtual environment wherever possible.

How to convert a string to a date in sybase

102 is the rule of thumb, convert (varchar, creat_tms, 102) > '2011'

Disable button in angular with two conditions?

Using the ternary operator is possible like following.[disabled] internally required true or false for its operation.

<button type="button" 
  [disabled]="(testVariable1 != 0 || testVariable2!=0)? true:false"
  mat-button>Button</button>

Check folder size in Bash

Use a summary (-s) and bytes (-b). You can cut the first field of the summary with cut. Putting it all together:

CHECK=$(du -sb /data/sflow_log | cut -f1)

How to update Ruby to 1.9.x on Mac?

I'll make a strong suggestion for rvm.

It's a great way to manage multiple Rubies and gems sets without colliding with the system version.


I'll add that now (4/2/2013), I use rbenv a lot, because my needs are simple. RVM is great, but it's got a lot of capability I never need, so I have it on some machines and rbenv on my desktop and laptop. It's worth checking out both and seeing which works best for your needs.

Printing Python version in output

import platform
print(platform.python_version())

This prints something like

3.7.2

How to get the bluetooth devices as a list?

You should change your code as below:

BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();

List<String> s = new ArrayList<String>();
for(BluetoothDevice bt : pairedDevices)
   s.add(bt.getName());

setListAdapter(new ArrayAdapter<String>(this, R.layout.list, s));

How to use org.apache.commons package?

You are supposed to download the jar files that contain these libraries. Libraries may be used by adding them to the classpath.

For Commons Net you need to download the binary files from Commons Net download page. Then you have to extract the file and add the commons-net-2-2.jar file to some location where you can access it from your application e.g. to /lib.

If you're running your application from the command-line you'll have to define the classpath in the java command: java -cp .;lib/commons-net-2-2.jar myapp. More info about how to set the classpath can be found from Oracle documentation. You must specify all directories and jar files you'll need in the classpath excluding those implicitely provided by the Java runtime. Notice that there is '.' in the classpath, it is used to include the current directory in case your compiled class is located in the current directory.

For more advanced reading, you might want to read about how to define the classpath for your own jar files, or the directory structure of a war file when you're creating a web application.

If you are using an IDE, such as Eclipse, you have to remember to add the library to your build path before the IDE will recognize it and allow you to use the library.

Automatic exit from Bash shell script on error

One idiom is:

cd some_dir && ./configure --some-flags && make && make install

I realize that can get long, but for larger scripts you could break it into logical functions.

How to create a drop-down list?

Try this:

package example.spin.spinnerexample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener{

    String[] bankNames={"BOI","SBI","HDFC","PNB","OBC"};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //Getting the instance of Spinner and applying OnItemSelectedListener on it
        Spinner spin = (Spinner) findViewById(R.id.simpleSpinner);
        spin.setOnItemSelectedListener(this);

        //Creating the ArrayAdapter instance having the bank name list
        ArrayAdapter aa = new ArrayAdapter(this,android.R.layout.simple_spinner_item,bankNames);
        aa.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        //Setting the ArrayAdapter data on the Spinner
        spin.setAdapter(aa);
    }


    //Performing action onItemSelected and onNothing selected
    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1, int position,long id) {
        Toast.makeText(getApplicationContext(), bankNames[position], Toast.LENGTH_LONG).show();
    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub

    }
}

activity_main.xml:-

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">

    <Spinner
        android:id="@+id/simpleSpinner"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="100dp" />

</RelativeLayout>

Storing Objects in HTML5 localStorage

localStorage.setItem('user', JSON.stringify(user));

Then to retrieve it from the store and convert to an object again:

var user = JSON.parse(localStorage.getItem('user'));

If we need to delete all entries of the store we can simply do:

localStorage.clear();

HTML Button Close Window

Closing a window that was opened by the user through JavaScript is considered to be a security risk, thus not all browsers will allow this (which is why all solutions are hacks/workarounds). Browsers that are steadily maintained remove these types of hacks, and solutions that work one day may be broken the next.

This was addressed here by rvighne in a similar question on the subject.

What is the difference between .py and .pyc files?

Python compiles the .py and saves files as .pyc so it can reference them in subsequent invocations.

There's no harm in deleting them, but they will save compilation time if you're doing lots of processing.

How to send email to multiple recipients with addresses stored in Excel?

ToAddress = "[email protected]"
ToAddress1 = "[email protected]"
ToAddress2 = "[email protected]"
MessageSubject = "It works!."
Set ol = CreateObject("Outlook.Application")
Set newMail = ol.CreateItem(olMailItem)
newMail.Subject = MessageSubject
newMail.RecipIents.Add(ToAddress)
newMail.RecipIents.Add(ToAddress1)
newMail.RecipIents.Add(ToAddress2)
newMail.Send

Access all Environment properties as a Map or Properties object

I though I'd add one more way. In my case I supply this to com.hazelcast.config.XmlConfigBuilder which only needs java.util.Properties to resolve some properties inside the Hazelcast XML configuration file, i.e. it only calls getProperty(String) method. So, this allowed me to do what I needed:

@RequiredArgsConstructor
public class SpringReadOnlyProperties extends Properties {

  private final org.springframework.core.env.Environment delegate;

  @Override
  public String getProperty(String key) {
    return delegate.getProperty(key);
  }

  @Override
  public String getProperty(String key, String defaultValue) {
    return delegate.getProperty(key, defaultValue);
  }

  @Override
  public synchronized String toString() {
    return getClass().getName() + "{" + delegate + "}";
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;
    if (!super.equals(o)) return false;
    SpringReadOnlyProperties that = (SpringReadOnlyProperties) o;
    return delegate.equals(that.delegate);
  }

  @Override
  public int hashCode() {
    return Objects.hash(super.hashCode(), delegate);
  }

  private void throwException() {
    throw new RuntimeException("This method is not supported");
  }

  //all methods below throw the exception

  * override all methods *
}

P.S. I ended up not using this specifically for Hazelcast because it only resolves properties for XML file but not at runtime. Since I also use Spring, I decided to go with a custom org.springframework.cache.interceptor.AbstractCacheResolver#getCacheNames. This resolves properties for both situations, at least if you use properties in cache names.

Is there a limit on how much JSON can hold?

The maximum length of JSON strings. The default is 2097152 characters, which is equivalent to 4 MB of Unicode string data.

Refer below URL

https://docs.microsoft.com/en-us/dotnet/api/system.web.script.serialization.javascriptserializer.maxjsonlength?view=netframework-4.7.2

eslint: error Parsing error: The keyword 'const' is reserved

I used .eslintrc.js and I have added following code.

module.exports = {
    "parserOptions": {
        "ecmaVersion": 6
    }
};

Using FolderBrowserDialog in WPF application

You need to add a reference to System.Windows.Forms.dll, then use the System.Windows.Forms.FolderBrowserDialog class.

Adding using WinForms = System.Windows.Forms; will be helpful.

How to split a string, but also keep the delimiters?

I don't know of an existing function in the Java API that does this (which is not to say it doesn't exist), but here's my own implementation (one or more delimiters will be returned as a single token; if you want each delimiter to be returned as a separate token, it will need a bit of adaptation):

static String[] splitWithDelimiters(String s) {
    if (s == null || s.length() == 0) {
        return new String[0];
    }
    LinkedList<String> result = new LinkedList<String>();
    StringBuilder sb = null;
    boolean wasLetterOrDigit = !Character.isLetterOrDigit(s.charAt(0));
    for (char c : s.toCharArray()) {
        if (Character.isLetterOrDigit(c) ^ wasLetterOrDigit) {
            if (sb != null) {
                result.add(sb.toString());
            }
            sb = new StringBuilder();
            wasLetterOrDigit = !wasLetterOrDigit;
        }
        sb.append(c);
    }
    result.add(sb.toString());
    return result.toArray(new String[0]);
}

HTML <sup /> tag affecting line height, how to make it consistent?

keep it easy:

sup { vertical-align: text-top; }

[font-size dependent on your individual type-face]

Sorting object property by values

<pre>
function sortObjectByVal(obj){  
var keysSorted = Object.keys(obj).sort(function(a,b){return obj[b]-obj[a]});
var newObj = {};
for(var x of keysSorted){
    newObj[x] = obj[x];
}
return newObj;

}
var list = {"you": 100, "me": 75, "foo": 116, "bar": 15};
console.log(sortObjectByVal(list));
</pre>

Why do I need 'b' to encode a string with Base64?

Short Answer

You need to push a bytes-like object (bytes, bytearray, etc) to the base64.b64encode() method. Here are two ways:

>>> import base64
>>> data = base64.b64encode(b'data to be encoded')
>>> print(data)
b'ZGF0YSB0byBiZSBlbmNvZGVk'

Or with a variable:

>>> import base64
>>> string = 'data to be encoded'
>>> data = base64.b64encode(string.encode())
>>> print(data)
b'ZGF0YSB0byBiZSBlbmNvZGVk'

Why?

In Python 3, str objects are not C-style character arrays (so they are not byte arrays), but rather, they are data structures that do not have any inherent encoding. You can encode that string (or interpret it) in a variety of ways. The most common (and default in Python 3) is utf-8, especially since it is backwards compatible with ASCII (although, as are most widely-used encodings). That is what is happening when you take a string and call the .encode() method on it: Python is interpreting the string in utf-8 (the default encoding) and providing you the array of bytes that it corresponds to.

Base-64 Encoding in Python 3

Originally the question title asked about Base-64 encoding. Read on for Base-64 stuff.

base64 encoding takes 6-bit binary chunks and encodes them using the characters A-Z, a-z, 0-9, '+', '/', and '=' (some encodings use different characters in place of '+' and '/'). This is a character encoding that is based off of the mathematical construct of radix-64 or base-64 number system, but they are very different. Base-64 in math is a number system like binary or decimal, and you do this change of radix on the entire number, or (if the radix you're converting from is a power of 2 less than 64) in chunks from right to left.

In base64 encoding, the translation is done from left to right; those first 64 characters are why it is called base64 encoding. The 65th '=' symbol is used for padding, since the encoding pulls 6-bit chunks but the data it is usually meant to encode are 8-bit bytes, so sometimes there are only two or 4 bits in the last chunk.

Example:

>>> data = b'test'
>>> for byte in data:
...     print(format(byte, '08b'), end=" ")
...
01110100 01100101 01110011 01110100
>>>

If you interpret that binary data as a single integer, then this is how you would convert it to base-10 and base-64 (table for base-64):

base-2:  01 110100 011001 010111 001101 110100 (base-64 grouping shown)
base-10:                            1952805748
base-64:  B      0      Z      X      N      0

base64 encoding, however, will re-group this data thusly:

base-2:  011101  000110  010101 110011 011101 00(0000) <- pad w/zeros to make a clean 6-bit chunk
base-10:     29       6      21     51     29      0
base-64:      d       G       V      z      d      A

So, 'B0ZXN0' is the base-64 version of our binary, mathematically speaking. However, base64 encoding has to do the encoding in the opposite direction (so the raw data is converted to 'dGVzdA') and also has a rule to tell other applications how much space is left off at the end. This is done by padding the end with '=' symbols. So, the base64 encoding of this data is 'dGVzdA==', with two '=' symbols to signify two pairs of bits will need to be removed from the end when this data gets decoded to make it match the original data.

Let's test this to see if I am being dishonest:

>>> encoded = base64.b64encode(data)
>>> print(encoded)
b'dGVzdA=='

Why use base64 encoding?

Let's say I have to send some data to someone via email, like this data:

>>> data = b'\x04\x6d\x73\x67\x08\x08\x08\x20\x20\x20'
>>> print(data.decode())
   
>>> print(data)
b'\x04msg\x08\x08\x08   '
>>>

There are two problems I planted:

  1. If I tried to send that email in Unix, the email would send as soon as the \x04 character was read, because that is ASCII for END-OF-TRANSMISSION (Ctrl-D), so the remaining data would be left out of the transmission.
  2. Also, while Python is smart enough to escape all of my evil control characters when I print the data directly, when that string is decoded as ASCII, you can see that the 'msg' is not there. That is because I used three BACKSPACE characters and three SPACE characters to erase the 'msg'. Thus, even if I didn't have the EOF character there the end user wouldn't be able to translate from the text on screen to the real, raw data.

This is just a demo to show you how hard it can be to simply send raw data. Encoding the data into base64 format gives you the exact same data but in a format that ensures it is safe for sending over electronic media such as email.

How do I read input character-by-character in Java?

Use Reader.read(). A return value of -1 means end of stream; else, cast to char.

This code reads character data from a list of file arguments:

public class CharacterHandler {
    //Java 7 source level
    public static void main(String[] args) throws IOException {
        // replace this with a known encoding if possible
        Charset encoding = Charset.defaultCharset();
        for (String filename : args) {
            File file = new File(filename);
            handleFile(file, encoding);
        }
    }

    private static void handleFile(File file, Charset encoding)
            throws IOException {
        try (InputStream in = new FileInputStream(file);
             Reader reader = new InputStreamReader(in, encoding);
             // buffer for efficiency
             Reader buffer = new BufferedReader(reader)) {
            handleCharacters(buffer);
        }
    }

    private static void handleCharacters(Reader reader)
            throws IOException {
        int r;
        while ((r = reader.read()) != -1) {
            char ch = (char) r;
            System.out.println("Do something with " + ch);
        }
    }
}

The bad thing about the above code is that it uses the system's default character set. Wherever possible, prefer a known encoding (ideally, a Unicode encoding if you have a choice). See the Charset class for more. (If you feel masochistic, you can read this guide to character encoding.)

(One thing you might want to look out for are supplementary Unicode characters - those that require two char values to store. See the Character class for more details; this is an edge case that probably won't apply to homework.)

how do you filter pandas dataframes by multiple columns

You can filter by multiple columns (more than two) by using the np.logical_and operator to replace & (or np.logical_or to replace |)

Here's an example function that does the job, if you provide target values for multiple fields. You can adapt it for different types of filtering and whatnot:

def filter_df(df, filter_values):
    """Filter df by matching targets for multiple columns.

    Args:
        df (pd.DataFrame): dataframe
        filter_values (None or dict): Dictionary of the form:
                `{<field>: <target_values_list>}`
            used to filter columns data.
    """
    import numpy as np
    if filter_values is None or not filter_values:
        return df
    return df[
        np.logical_and.reduce([
            df[column].isin(target_values) 
            for column, target_values in filter_values.items()
        ])
    ]

Usage:

df = pd.DataFrame({'a': [1, 2, 3, 4], 'b': [1, 2, 3, 4]})

filter_df(df, {
    'a': [1, 2, 3],
    'b': [1, 2, 4]
})

Convert HTML Character Back to Text Using Java Standard Library

As @jem suggested, it is possible to use jsoup.

With jSoup 1.8.3 it il possible to use the method Parser.unescapeEntities that retain the original html.

import org.jsoup.parser.Parser;
...
String html = Parser.unescapeEntities(original_html, false);

It seems that in some previous release this method is not present.

How to use PHP with Visual Studio

Try Visual Studio Code. Very good support for PHP and other languages directly or via extensions. It can not replace power of Visual Studio but it is powerful addition to Visual Studio. And you can run it on all OS (Windows, Linux, Mac...).

https://code.visualstudio.com/

Javascript/Jquery to change class onclick?

I would think this: http://jsfiddle.net/Skooljester/S3y5p/1/ should do it. If I don't have the class names 100% correct you can just change them to whatever you need them to be.

How to call a .NET Webservice from Android using KSOAP2?

It's very simple. You are getting the result into an Object which is a primitive one.

Your code:

Object result = (Object)envelope.getResponse();

Correct code:

SoapObject result=(SoapObject)envelope.getResponse();

//To get the data.
String resultData=result.getProperty(0).toString();
// 0 is the first object of data.

I think this should definitely work.

How to run a maven created jar file using just the command line

I am not sure in your case. But as I know to run any jar file from cmd we can use following command:

Go up to the directory where your jar file is saved:

java -jar <jarfilename>.jar

But you can check following links. I hope it'll help you:

Run Netbeans maven project from command-line?

http://www.sonatype.com/books/mvnref-book/reference/running-sect-options.html

How to close a Java Swing application from the code

Try:

System.exit(0);

Crude, but effective.

m2eclipse error

This what helped me:

  1. Delete the project from eclipse (but don't delete from disk)
  2. Close eclipse
  3. In your user folder there is .m folder. Delete repository folder underneath it (.m/repository).
  4. Open eclipse
  5. Import project as existing maven project (from disk).

Good luck.

mysql -> insert into tbl (select from another table) and some default values

INSERT INTO def (field_1, field_2, field3) 
VALUES 
('$field_1', (SELECT id_user from user_table where name = 'jhon'), '$field3')

Spark - Error "A master URL must be set in your configuration" when submitting an app

The TLDR:

.config("spark.master", "local")

a list of the options for spark.master in spark 2.2.1

I ended up on this page after trying to run a simple Spark SQL java program in local mode. To do this, I found that I could set spark.master using:

SparkSession spark = SparkSession
.builder()
.appName("Java Spark SQL basic example")
.config("spark.master", "local")
.getOrCreate();

An update to my answer:

To be clear, this is not what you should do in a production environment. In a production environment, spark.master should be specified in one of a couple other places: either in $SPARK_HOME/conf/spark-defaults.conf (this is where cloudera manager will put it), or on the command line when you submit the app. (ex spark-submit --master yarn).

If you specify spark.master to be 'local' in this way, spark will try to run in a single jvm, as indicated by the comments below. If you then try to specify --deploy-mode cluster, you will get an error 'Cluster deploy mode is not compatible with master "local"'. This is because setting spark.master=local means that you are NOT running in cluster mode.

Instead, for a production app, within your main function (or in functions called by your main function), you should simply use:

SparkSession
.builder()
.appName("Java Spark SQL basic example")
.getOrCreate();

This will use the configurations specified on the command line/in config files.

Also, to be clear on this too: --master and "spark.master" are the exact same parameter, just specified in different ways. Setting spark.master in code, like in my answer above, will override attempts to set --master, and will override values in spark-defaults.conf, so don't do it in production. Its great for tests though.

also, see this answer. which links to a list of the options for spark.master and what each one actually does.

a list of the options for spark.master in spark 2.2.1

Slide up/down effect with ng-show and ng-animate

This class-based javascript animation works in AngularJS 1.2 (and 1.4 tested)

Edit: I ended up abandoning this code and went a completely different direction. I like my other answer much better. This answer will give you some problems in certain situations.

myApp.animation('.ng-show-toggle-slidedown', function(){
  return {
    beforeAddClass : function(element, className, done){
        if (className == 'ng-hide'){
            $(element).slideUp({duration: 400}, done);
        } else {done();}
    },
    beforeRemoveClass :  function(element, className, done){
        if (className == 'ng-hide'){
            $(element).css({display:'none'});
            $(element).slideDown({duration: 400}, done);
        } else {done();}
    }
}

});

Simply add the .ng-hide-toggle-slidedown class to the container element, and the jQuery slide down behavior will be implemented based on the ng-hide class.

You must include the $(element).css({display:'none'}) line in the beforeRemoveClass method because jQuery will not execute a slideDown unless the element is in a state of display: none prior to starting the jQuery animation. AngularJS uses the CSS

.ng-hide:not(.ng-hide-animate) {
    display: none !important;
}

to hide the element. jQuery is not aware of this state, and jQuery will need the display:none prior to the first slide down animation.

The AngularJS animation will add the .ng-hide-animate and .ng-animate classes while the animation is occuring.

PHP: Return all dates between two dates in an array

<?
print_r(getDatesFromRange( '2010-10-01', '2010-10-05' ));

function getDatesFromRange($startDate, $endDate)
{
    $return = array($startDate);
    $start = $startDate;
    $i=1;
    if (strtotime($startDate) < strtotime($endDate))
    {
       while (strtotime($start) < strtotime($endDate))
        {
            $start = date('Y-m-d', strtotime($startDate.'+'.$i.' days'));
            $return[] = $start;
            $i++;
        }
    }

    return $return;
}

How to get an absolute file path in Python

In case someone is using python and linux and looking for full path to file:

>>> path=os.popen("readlink -f file").read()
>>> print path
abs/path/to/file

Export to CSV via PHP

Works with over 100 lines, if you specify the size of the file in the headers simple call the get() method in your own class

function setHeader($filename, $filesize)
{
    // disable caching
    $now = gmdate("D, d M Y H:i:s");
    header("Expires: Tue, 01 Jan 2001 00:00:01 GMT");
    header("Cache-Control: max-age=0, no-cache, must-revalidate, proxy-revalidate");
    header("Last-Modified: {$now} GMT");

    // force download  
    header("Content-Type: application/force-download");
    header("Content-Type: application/octet-stream");
    header("Content-Type: application/download");
    header('Content-Type: text/x-csv');

    // disposition / encoding on response body
    if (isset($filename) && strlen($filename) > 0)
        header("Content-Disposition: attachment;filename={$filename}");
    if (isset($filesize))
        header("Content-Length: ".$filesize);
    header("Content-Transfer-Encoding: binary");
    header("Connection: close");
}

function getSql()
{
    // return you own sql
    $sql = "SELECT id, date, params, value FROM sometable ORDER BY date;";
    return $sql;
}

function getExportData()
{
    $values = array();

    $sql = $this->getSql();
    if (strlen($sql) > 0)
    {
        $result = dbquery($sql); // opens the database and executes the sql ... make your own ;-) 
        $fromDb = mysql_fetch_assoc($result);
        if ($fromDb !== false)
        {
            while ($fromDb)
            {
                $values[] = $fromDb;
                $fromDb = mysql_fetch_assoc($result);
            }
        }
    }
    return $values;
}

function get()
{
    $values = $this->getExportData(); // values as array 
    $csv = tmpfile();

    $bFirstRowHeader = true;
    foreach ($values as $row) 
    {
        if ($bFirstRowHeader)
        {
            fputcsv($csv, array_keys($row));
            $bFirstRowHeader = false;
        }

        fputcsv($csv, array_values($row));
    }

    rewind($csv);

    $filename = "export_".date("Y-m-d").".csv";

    $fstat = fstat($csv);
    $this->setHeader($filename, $fstat['size']);

    fpassthru($csv);
    fclose($csv);
}

oracle plsql: how to parse XML and insert into table

CREATE OR REPLACE PROCEDURE ADDEMP
    (xml IN CLOB)
AS
BEGIN
    INSERT INTO EMPLOYEE (EMPID,EMPNAME,EMPDETAIL,CREATEDBY,CREATED)
    SELECT 
        ExtractValue(column_value,'/ROOT/EMPID') AS EMPID
       ,ExtractValue(column_value,'/ROOT/EMPNAME') AS EMPNAME
       ,ExtractValue(column_value,'/ROOT/EMPDETAIL') AS EMPDETAIL
       ,ExtractValue(column_value,'/ROOT/CREATEDBY') AS CREATEDBY
       ,ExtractValue(column_value,'/ROOT/CREATEDDATE') AS CREATEDDATE
    FROM   TABLE(XMLSequence( XMLType(xml))) XMLDUMMAY;

    COMMIT;
END;

Under which circumstances textAlign property works in Flutter?

For maximum flexibility, I usually prefer working with SizedBox like this:

Row(
                                children: <Widget>[
                                  SizedBox(
                                      width: 235,
                                      child: Text('Hey, ')),
                                  SizedBox(
                                      width: 110,
                                      child: Text('how are'),
                                  SizedBox(
                                      width: 10,
                                      child: Text('you?'))
                                ],
                              )

I've experienced problems with text alignment when using alignment in the past, whereas sizedbox always does the work.

Django Multiple Choice Field / Checkbox Select Multiple

The easiest way I found (just I use eval() to convert string gotten from input to tuple to read again for form instance or other place)

This trick works very well

#model.py
class ClassName(models.Model):
    field_name = models.CharField(max_length=100)

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        if self.field_name:
            self.field_name= eval(self.field_name)



#form.py
CHOICES = [('pi', 'PI'), ('ci', 'CI')]

class ClassNameForm(forms.ModelForm):
    field_name = forms.MultipleChoiceField(choices=CHOICES)

    class Meta:
        model = ClassName
        fields = ['field_name',]

Make .gitignore ignore everything except a few files

The simplest way that I go about this is to force add a file. It will be accounted for in git even if it is buried or nested inside a git-ignored subdirectory tree.

For example:

x64 folder is excluded in .gitignore:

x64/

But you want to include the file myFile.py located in x64/Release/ directory. Then you have to:

git add -f x64/Release/myFile.py

You can do this for multiple files of files that match a pattern e.g.

git add -f x64/Release/myFile*.py

and so on.

How to get the instance id from within an ec2 instance?

If you wish to get the all instances id list in python here is the code:

import boto3

ec2=boto3.client('ec2')
instance_information = ec2.describe_instances()

for reservation in instance_information['Reservations']:
   for instance in reservation['Instances']:
      print(instance['InstanceId'])

Java 8 Distinct by property

The easiest way to implement this is to jump on the sort feature as it already provides an optional Comparator which can be created using an element’s property. Then you have to filter duplicates out which can be done using a statefull Predicate which uses the fact that for a sorted stream all equal elements are adjacent:

Comparator<Person> c=Comparator.comparing(Person::getName);
stream.sorted(c).filter(new Predicate<Person>() {
    Person previous;
    public boolean test(Person p) {
      if(previous!=null && c.compare(previous, p)==0)
        return false;
      previous=p;
      return true;
    }
})./* more stream operations here */;

Of course, a statefull Predicate is not thread-safe, however if that’s your need you can move this logic into a Collector and let the stream take care of the thread-safety when using your Collector. This depends on what you want to do with the stream of distinct elements which you didn’t tell us in your question.

'numpy.ndarray' object is not callable error

The error TypeError: 'numpy.ndarray' object is not callable means that you tried to call a numpy array as a function. We can reproduce the error like so in the repl:

In [16]: import numpy as np

In [17]: np.array([1,2,3])()
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
/home/user/<ipython-input-17-1abf8f3c8162> in <module>()
----> 1 np.array([1,2,3])()

TypeError: 'numpy.ndarray' object is not callable

If we are to assume that the error is indeed coming from the snippet of code that you posted (something that you should check,) then you must have reassigned either pd.rolling_mean or pd.rolling_std to a numpy array earlier in your code.

What I mean is something like this:

In [1]: import numpy as np

In [2]: import pandas as pd

In [3]: pd.rolling_mean(np.array([1,2,3]), 20, min_periods=5) # Works
Out[3]: array([ nan,  nan,  nan])

In [4]: pd.rolling_mean = np.array([1,2,3])

In [5]: pd.rolling_mean(np.array([1,2,3]), 20, min_periods=5) # Doesn't work anymore...
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
/home/user/<ipython-input-5-f528129299b9> in <module>()
----> 1 pd.rolling_mean(np.array([1,2,3]), 20, min_periods=5) # Doesn't work anymore...

TypeError: 'numpy.ndarray' object is not callable

So, basically you need to search the rest of your codebase for pd.rolling_mean = ... and/or pd.rolling_std = ... to see where you may have overwritten them.


Also, if you'd like, you can put in reload(pd) just before your snippet, which should make it run by restoring the value of pd to what you originally imported it as, but I still highly recommend that you try to find where you may have reassigned the given functions.

How can I convert the "arguments" object to an array in JavaScript?

Another Answer.

Use Black Magic Spells:

function sortArguments() {
  arguments.__proto__ = Array.prototype;
  return arguments.slice().sort();
}

Firefox, Chrome, Node.js, IE11 are OK.

sed edit file in place

If you are replacing the same amount of characters and after carefully reading “In-place” editing of files...

You can also use the redirection operator <> to open the file to read and write:

sed 's/foo/bar/g' file 1<> file

See it live:

$ cat file
hello
i am here                           # see "here"
$ sed 's/here/away/' file 1<> file  # Run the `sed` command
$ cat file
hello
i am away                           # this line is changed now

From Bash Reference Manual ? 3.6.10 Opening File Descriptors for Reading and Writing:

The redirection operator

[n]<>word

causes the file whose name is the expansion of word to be opened for both reading and writing on file descriptor n, or on file descriptor 0 if n is not specified. If the file does not exist, it is created.

How to get screen width without (minus) scrollbar?

I experienced a similar problem and doing width:100%; solved it for me. I came to this solution after trying an answer in this question and realizing that the very nature of an <iframe> will make these javascript measurement tools inaccurate without using some complex function. Doing 100% is a simple way to take care of it in an iframe. I don't know about your issue since I'm not sure of what HTML elements you are manipulating.

Pylint "unresolved import" error in Visual Studio Code

If you have this code in your settings.json file, delete it:

{
    "python.jediEnabled": false
}

Convert JSON String to JSON Object c#

This does't work in case of the JObject this works for the simple json format data. I have tried my data of the below json format data to deserialize in the type but didn't get the response.

For this Json

{
  "Customer": {
    "id": "Shell",
    "Installations": [
      {
        "id": "Shell.Bangalore",
        "Stations": [
          {
            "id": "Shell.Bangalore.BTM",
            "Pumps": [
              {
                "id": "Shell.Bangalore.BTM.pump1"
              },
              {
                "id": "Shell.Bangalore.BTM.pump2"
              },
              {
                "id": "Shell.Bangalore.BTM.pump3"
              }
            ]
          },
          {
            "id": "Shell.Bangalore.Madiwala",
            "Pumps": [
              {
                "id": "Shell.Bangalore.Madiwala.pump4"
              },
              {
                "id": "Shell.Bangalore.Madiwala.pump5"
              }
            ]
          }
        ]
      }
    ]
  }
}

Find element in List<> that contains a value

Using function Find is cleaner way.

MyClass item = MyList.Find(item => item.name == "foo");
if (item != null) // check item isn't null
{
 ....
}

How to add New Column with Value to the Existing DataTable?

Without For loop:

Dim newColumn As New Data.DataColumn("Foo", GetType(System.String))     
newColumn.DefaultValue = "Your DropDownList value" 
table.Columns.Add(newColumn) 

C#:

System.Data.DataColumn newColumn = new System.Data.DataColumn("Foo", typeof(System.String));
newColumn.DefaultValue = "Your DropDownList value";
table.Columns.Add(newColumn);

Extract first item of each sublist

Using list comprehension:

>>> lst = [['a','b','c'], [1,2,3], ['x','y','z']]
>>> lst2 = [item[0] for item in lst]
>>> lst2
['a', 1, 'x']

Bash: Strip trailing linebreak from output

There is also direct support for white space removal in Bash variable substitution:

testvar=$(wc -l < log.txt)
trailing_space_removed=${testvar%%[[:space:]]}
leading_space_removed=${testvar##[[:space:]]}

In vb.net, how to get the column names from a datatable

' i modify the code for Datatable 

For Each c as DataColumn in dt.Columns
 For j=0 To _dataTable.Columns.Count-1
            xlWorksheet.Cells (i+1, j+1) = _dataTable.Columns(j).ColumnName
Next
Next

Hope this could be help!

Doing HTTP requests FROM Laravel to an external API

You just want to call an external URL and use the results? PHP does this out of the box, if we're talking about a simple GET request to something serving JSON:

$json = json_decode(file_get_contents('http://host.com/api/stuff/1'), true);

If you want to do a post request, it's a little harder but there's loads of examples how to do this with curl.

So I guess the question is; what exactly do you want?

How to select a schema in postgres when using psql?

if you in psql just type

set schema 'temp';

and after that \d shows all relations in "temp

How to run composer from anywhere?

Simply run this command for installing composer globally

curl -sS https://getcomposer.org/installer | sudo php -- --install-dir=/usr/local/bin --filename=composer

How to add AUTO_INCREMENT to an existing column?

Alter table table_name modify table_name.column_name data_type AUTO_INCREMENT;

eg:

Alter table avion modify avion.av int AUTO_INCREMENT;

C++ vector of char array

In fact technically you can store C++ arrays in a vector, and it makes a lot of sense. Not directly, but by a simple workaround, wrapping in a class, will meet exactly all the requirements of a multidimensional array. As the question is already answered by anon. Some explanations steel needed. STL already provides std::array for these purposes.
Is an unpleasant surprise to fall in the trap of not understanding clearly the difference between arrays and pointers, between multidimensional arrays and arrays of arrays, and so on and so on. Vectors of vectors contains vectors as elements. Each element containing a copy of size, capacity and maybe other things, meanwhile the vector datas for elements will be placed in different random places in memory. But a vector of arrays will contain a contiguous segment of memory with all data, which is identical to multidimensional array. Also there is no good reason to keep the size of each array element while it is known to be the same for all elements. So, making a vector of array, you can't do it directly. But you can workaround it easily by wrapping the array in a class, and in this sample the memory will be identical to the memory of a bidimensional array. This approach is already widely used by many libraries. At low level it will be easily interoperable with APIs that are not C++ vector aware. So without using std::array it will look like this:

int main()
{
    struct ss
    {
        int a[5];
        int& operator[] (const int& i) { return a[i]; }
    } a{ 1,2,3,4,5 }, b{ 9,8,7,6,5 };

    vector<ss> v;
    v.resize(10);
    v[0] = a;
    v[1] = b;
    v.push_back(a); // will push to index 10, with reallocation
    v.push_back(b); // will push to index 11, with reallocation

    auto d = v.data();
    // cin >> v[1][3]; //input any element from stdin
    cout << "show two element: "<< v[1][2] <<":"<< v[1][3] << endl;
    return 0;
}

Since C++11 STL contains std::array for these purposes, so no need to reinvent it:

....
#include<array>
....
int main()
{
    vector<array<int, 5>> v;
    v.reserve(10);
    v.resize(2);
    v[0] = array<int, 5> {1, 2, 3, 4, 5};
    v[1] = array<int, 5> {9, 8, 7, 6, 5};
    v.emplace_back(array<int, 5>{ 7, 2, 53, 4, 5 });
    ///cin >> v[1][1];
    auto d = v.data();

Now look how looks in memory


Now, this is why vectors of vectors is not the answer. Supposing following code

int main()
{
    vector<vector<int>> vv = { { 1,2,3,4,5 }, { 9,8,7,6,5 } };
    auto dd = vv.data();
    return 0;
}

Guess what it looks like in the memory now

setImmediate vs. nextTick

As an illustration

import fs from 'fs';
import http from 'http';

const options = {
  host: 'www.stackoverflow.com',
  port: 80,
  path: '/index.html'
};

describe('deferredExecution', () => {
  it('deferredExecution', (done) => {
    console.log('Start');
    setTimeout(() => console.log('TO1'), 0);
    setImmediate(() => console.log('IM1'));
    process.nextTick(() => console.log('NT1'));
    setImmediate(() => console.log('IM2'));
    process.nextTick(() => console.log('NT2'));
    http.get(options, () => console.log('IO1'));
    fs.readdir(process.cwd(), () => console.log('IO2'));
    setImmediate(() => console.log('IM3'));
    process.nextTick(() => console.log('NT3'));
    setImmediate(() => console.log('IM4'));
    fs.readdir(process.cwd(), () => console.log('IO3'));
    console.log('Done');
    setTimeout(done, 1500);
  });
});

will give the following output

Start
Done
NT1
NT2
NT3
TO1
IO2
IO3
IM1
IM2
IM3
IM4
IO1

I hope this can help to understand the difference.

Updated:

Callbacks deferred with process.nextTick() run before any other I/O event is fired, while with setImmediate(), the execution is queued behind any I/O event that is already in the queue.

Node.js Design Patterns, by Mario Casciaro (probably the best book about node.js/js)

WPF Binding to parent DataContext

I dont know about XamGrid but that's what i'll do with a standard wpf DataGrid:

<DataGrid>
    <DataGrid.Columns>
        <DataGridTemplateColumn>
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding DataContext.MyProperty, RelativeSource={RelativeSource AncestorType=MyUserControl}}"/>
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
            <DataGridTemplateColumn.CellEditingTemplate>
                <DataTemplate>
                    <TextBox Text="{Binding DataContext.MyProperty, RelativeSource={RelativeSource AncestorType=MyUserControl}}"/>
                </DataTemplate>
            </DataGridTemplateColumn.CellEditingTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

Since the TextBlock and the TextBox specified in the cell templates will be part of the visual tree, you can walk up and find whatever control you need.

Modulo operator with negative values

From ISO14882:2011(e) 5.6-4:

The binary / operator yields the quotient, and the binary % operator yields the remainder from the division of the first expression by the second. If the second operand of / or % is zero the behavior is undefined. For integral operands the / operator yields the algebraic quotient with any fractional part discarded; if the quotient a/b is representable in the type of the result, (a/b)*b + a%b is equal to a.

The rest is basic math:

(-7/3) => -2
-2 * 3 => -6
so a%b => -1

(7/-3) => -2
-2 * -3 => 6
so a%b => 1

Note that

If both operands are nonnegative then the remainder is nonnegative; if not, the sign of the remainder is implementation-defined.

from ISO14882:2003(e) is no longer present in ISO14882:2011(e)

Remove trailing zeros from decimal in SQL Server

I had a similar issue, but was also required to remove the decimal point where no decimal was present, here was my solution which splits the decimal into its components, and bases the number of characters it takes from the decimal point string on the length of the fraction component (without using CASE). To make matters even more interesting, my number was stored as a float without its decimals.

DECLARE @MyNum FLOAT
SET @MyNum = 700000
SELECT CAST(PARSENAME(CONVERT(NUMERIC(15,2),@MyNum/10000),2) AS VARCHAR(10)) 
+ SUBSTRING('.',1,LEN(REPLACE(RTRIM(REPLACE(CAST(PARSENAME(CONVERT(NUMERIC(15,2),@MyNum/10000),1) AS VARCHAR(2)),'0',' ')),' ','0'))) 
+ REPLACE(RTRIM(REPLACE(CAST(PARSENAME(CONVERT(NUMERIC(15,2),@MyNum/10000),1) AS VARCHAR(2)),'0',' ')),' ','0') 

The result is painful, I know, but I got there, with much help from the answers above.

Read a text file line by line in Qt

Since Qt 5.5 you can use QTextStream::readLineInto. It behaves similar to std::getline and is maybe faster as QTextStream::readLine, because it reuses the string:

QIODevice* device;
QTextStream in(&device);

QString line;
while (in.readLineInto(&line)) {
  // ...
}

how to set windows service username and password through commandline

In PowerShell, the "sc" command is an alias for the Set-Content cmdlet. You can workaround this using the following syntax:

sc.exe config Service obj= user password= pass

Specyfying the .exe extension, PowerShell bypasses the alias lookup.

HTH

Shortest distance between a point and a line segment

This algorithm is based on finding the intersection between the specified line and the orthogonal line, which contains the specified point, and calculating its distance. In case of a line segment, we must check if the intersection is between points of the line segment, if that's not the case then the minimum distance is between the specified point and one of the ending points of the line segment. This is a C# implementation.

Double Distance(Point a, Point b)
{
    double xdiff = a.X - b.X, ydiff = a.Y - b.Y;
    return Math.Sqrt((long)xdiff * xdiff + (long)ydiff * ydiff);
}

Boolean IsBetween(double x, double a, double b)
{
    return ((a <= b && x >= a && x <= b) || (a > b && x <= a && x >= b));
}

Double GetDistance(Point pt, Point pt1, Point pt2, out Point intersection)
{
    Double a, x, y, R;

    if (pt1.X != pt2.X) {
        a = (double)(pt2.Y - pt1.Y) / (pt2.X - pt1.X);
        x = (a * (pt.Y - pt1.Y) + a * a * pt1.X + pt.X) / (a * a + 1);
        y = a * x + pt1.Y - a * pt1.X; }
    else { x = pt1.X;  y = pt.Y; }

    if (IsBetween(x, pt1.X, pt2.X) && IsBetween(y, pt1.Y, pt2.Y)) {
        intersection = new Point((int)x, (int)y);
        R = Distance(intersection, pt); }
    else {
        double d1 = Distance(pt, pt1), d2 = Distance(pt, pt2);
        if (d1 < d2) { intersection = pt1; R = d1; }
        else { intersection = pt2; R = d2; }}

    return R;
}

How does origin/HEAD get set?

Disclaimer: this is an update to Cascabel's answer, which I'm writing to save the curious some time.

I tried in vain to replicate (in Git 2.0.1) the remote HEAD is ambiguous message that Cascabel mentions in his answer; so I did a bit of digging (by cloning https://github.com/git/git and searching the log). It used to be that

Determining HEAD is ambiguous since it is done by comparing SHA1s.

In the case of multiple matches we return refs/heads/master if it
matches, else we return the first match we encounter. builtin-remote
needs all matches returned to it, so add a flag for it to request such.

(Commit 4229f1fa325870d6b24fe2a4c7d2ed5f14c6f771, dated Feb 27, 2009, found with git log --reverse --grep="HEAD is ambiguous")

However, the ambiguity in question has since been lifted:

One long-standing flaw in the pack transfer protocol used by "git
clone" was that there was no way to tell the other end which branch
"HEAD" points at, and the receiving end needed to guess.  A new
capability has been defined in the pack protocol to convey this
information so that cloning from a repository with more than one
branches pointing at the same commit where the HEAD is at now
reliably sets the initial branch in the resulting repository.

(Commit 9196a2f8bd46d36a285bdfa03b4540ed3f01f671, dated Nov 8, 2013, found with git log --grep="ambiguous" --grep="HEAD" --all-match)

Edit (thanks to torek):

$ git name-rev --name-only 9196a2f8bd46d36a285bdfa03b4540ed3f01f671
tags/v1.8.4.3~3

This means that, if you're using Git v1.8.4.3 or later, you shouldn't run into any ambiguous-remote-HEAD problem.

How to use relative paths without including the context root name?

This is a derivative of @Ralph suggestion that I've been using. Add the c:url to the top of your JSP.

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:url value="/" var="root" />

Then just reference the root variable in your page:

<link rel="stylesheet" href="${root}templates/style/main.css">

CSS Selector that applies to elements with two classes

Chain both class selectors (without a space in between):

.foo.bar {
    /* Styles for element(s) with foo AND bar classes */
}

If you still have to deal with ancient browsers like IE6, be aware that it doesn't read chained class selectors correctly: it'll only read the last class selector (.bar in this case) instead, regardless of what other classes you list.

To illustrate how other browsers and IE6 interpret this, consider this CSS:

* {
    color: black;
}

.foo.bar {
    color: red;
}

Output on supported browsers is:

<div class="foo">Hello Foo</div>       <!-- Not selected, black text [1] -->
<div class="foo bar">Hello World</div> <!-- Selected, red text [2] -->
<div class="bar">Hello Bar</div>       <!-- Not selected, black text [3] -->

Output on IE6 is:

<div class="foo">Hello Foo</div>       <!-- Not selected, black text [1] -->
<div class="foo bar">Hello World</div> <!-- Selected, red text [2] -->
<div class="bar">Hello Bar</div>       <!-- Selected, red text [2] -->

Footnotes:

  • Supported browsers:
    1. Not selected as this element only has class foo.
    2. Selected as this element has both classes foo and bar.
    3. Not selected as this element only has class bar.

  • IE6:
    1. Not selected as this element doesn't have class bar.
    2. Selected as this element has class bar, regardless of any other classes listed.

How can I get argv[] as int?

/*

    Input from command line using atoi, and strtol 
*/

#include <stdio.h>//printf, scanf
#include <stdlib.h>//atoi, strtol 

//strtol - converts a string to a long int 
//atoi - converts string to an int 

int main(int argc, char *argv[]){

    char *p;//used in strtol 
    int i;//used in for loop

    long int longN = strtol( argv[1],&p, 10);
    printf("longN = %ld\n",longN);

    //cast (int) to strtol
    int N = (int) strtol( argv[1],&p, 10);
    printf("N = %d\n",N);

    int atoiN;
    for(i = 0; i < argc; i++)
    {
        //set atoiN equal to the users number in the command line 
        //The C library function int atoi(const char *str) converts the string argument str to an integer (type int).
        atoiN = atoi(argv[i]);
    }

    printf("atoiN = %d\n",atoiN);
    //-----------------------------------------------------//
    //Get string input from command line 
    char * charN;

    for(i = 0; i < argc; i++)
    {
        charN = argv[i];
    }

    printf("charN = %s\n", charN); 

}

Hope this helps. Good luck!

Android device does not show up in adb list

for me the solution was to install de driver from sdk manager:

http://visualgdb.com/KB/usbdebug-manual/

Programmatically stop execution of python script?

The exit() and quit() built in functions do just what you want. No import of sys needed.

Alternatively, you can raise SystemExit, but you need to be careful not to catch it anywhere (which shouldn't happen as long as you specify the type of exception in all your try.. blocks).

TypeError: 'str' object cannot be interpreted as an integer

You are getting the error because range() only takes int values as parameters.

Try using int() to convert your inputs.

How to print a number with commas as thousands separators in JavaScript

My answer is the only answer that completely replaces jQuery with a much more sensible alternative:

function $(dollarAmount)
{
    const locale = 'en-US';
    const options = { style: 'currency', currency: 'USD' };
    return Intl.NumberFormat(locale, options).format(dollarAmount);
}

This solution not only adds commas, but it also rounds to the nearest penny in the event that you input an amount like $(1000.9999) you'll get $1,001.00. Additionally, the value you input can safely be a number or a string; it doesn't matter.

If you're dealing with money, but don't want a leading dollar sign shown on the amount, you can also add this function, which uses the previous function but removes the $:

function no$(dollarAmount)
{
    return $(dollarAmount).replace('$','');
}

If you're not dealing with money, and have varying decimal formatting requirements, here's a more versatile function:

function addCommas(number, minDecimalPlaces = 0, maxDecimalPlaces = Math.max(3,minDecimalPlaces))
{
    const options = {};
    options.maximumFractionDigits = maxDecimalPlaces;
    options.minimumFractionDigits = minDecimalPlaces;
    return Intl.NumberFormat('en-US',options).format(number);
}

Oh, and by the way, the fact that this code does not work in some old version of Internet Explorer is completely intentional. I try to break IE anytime that I can catch it not supporting modern standards.

Please remember that excessive praise, in the comment section, is considered off-topic. Instead, just shower me with up-votes.

Installing J2EE into existing eclipse IDE

You could install Web Tool Platform on top of your current installation to help you learn about Java EE. Download the Web Tools Platform by using Eclipse Software Update (Instruction at http://download.eclipse.org/webtools/updates/). It has features to get you going with learning Java EE. You could learn more about Web Tools Platform at http://www.eclipse.org/webtools/

Setting up PostgreSQL ODBC on Windows

Please note that you must install the driver for the version of your software client(MS access) not the version of the OS. that's mean that if your MS Access is a 32-bits version,you must install a 32-bit odbc driver. regards

Get index of selected option with jQuery

Good way to solve this in Jquery manner

$("#dropDownMenuKategorie option:selected").index()

Javascript - remove an array item by value

tag_story.splice(tag_story.indexOf(id_tag), 1);

How to get form values in Symfony2 controller

For not mapped form fields I use $form->get('inputName')->getViewData();

A tool to convert MATLAB code to Python

There are several tools for converting Matlab to Python code.

The only one that's seen recent activity (last commit from June 2018) is Small Matlab to Python compiler (also developed here: SMOP@chiselapp).

Other options include:

  • LiberMate: translate from Matlab to Python and SciPy (Requires Python 2, last update 4 years ago).
  • OMPC: Matlab to Python (a bit outdated).

Also, for those interested in an interface between the two languages and not conversion:

  • pymatlab: communicate from Python by sending data to the MATLAB workspace, operating on them with scripts and pulling back the resulting data.
  • Python-Matlab wormholes: both directions of interaction supported.
  • Python-Matlab bridge: use Matlab from within Python, offers matlab_magic for iPython, to execute normal matlab code from within ipython.
  • PyMat: Control Matlab session from Python.
  • pymat2: continuation of the seemingly abandoned PyMat.
  • mlabwrap, mlabwrap-purepy: make Matlab look like Python library (based on PyMat).
  • oct2py: run GNU Octave commands from within Python.
  • pymex: Embeds the Python Interpreter in Matlab, also on File Exchange.
  • matpy: Access MATLAB in various ways: create variables, access .mat files, direct interface to MATLAB engine (requires MATLAB be installed).
  • MatPy: Python package for numerical linear algebra and plotting with a MatLab-like interface.

Btw might be helpful to look here for other migration tips:

On a different note, though I'm not a fortran fan at all, for people who might find it useful there is:

How to take keyboard input in JavaScript?

Since event.keyCode is deprecated, I found the event.key useful in javascript. Below is an example for getting the names of the keyboard keys pressed (using an input element). They are given as a KeyboardEvent key text property:

_x000D_
_x000D_
function setMyKeyDownListener() {_x000D_
    window.addEventListener(_x000D_
      "keydown",_x000D_
      function(event) {MyFunction(event.key)}_x000D_
    )_x000D_
}_x000D_
_x000D_
function MyFunction (the_Key) {_x000D_
    alert("Key pressed is: "+the_Key);_x000D_
}
_x000D_
html { font-size: 4vw; background-color: green; color: white; padding: 1em; }
_x000D_
<body onload="setMyKeyDownListener()">_x000D_
    <div>_x000D_
        <input id="MyInputId">_x000D_
    </div>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Convert a negative number to a positive one in JavaScript

unsigned_value = Math.abs(signed_value);

Chart won't update in Excel (2007)

This is the only thing I've found to consistently update a chart. It cuts the root cause of the problem (I assume): the series data is getting cached in the chart. By forcing the chart to re-evaluate the series, we are clearing the cache.

' Force the charts to update
Set sht = ActiveSheet
For Each co In sht.ChartObjects
    co.Activate
    For Each sc In ActiveChart.SeriesCollection
        sc.Select
        temp = sc.Formula
        sc.Formula = "=SERIES(,,1,1)"
        sc.Formula = temp
    Next sc
Next co

Bad Request, Your browser sent a request that this server could not understand

If you are getting this error on the WordPress website, check the below solution.

  1. Corrupted Browser Cache & Cookies: Delete your Cookies and clear your cache
  2. Restart your server

Remove empty lines in a text file via grep

Perl might be overkill, but it works just as well.

Removes all lines which are completely blank:

perl -ne 'print if /./' file

Removes all lines which are completely blank, or only contain whitespace:

perl -ne 'print if ! /^\s*$/' file

Variation which edits the original and makes a .bak file:

perl -i.bak -ne 'print if ! /^\s*$/' file

Get user info via Google API

This scope https://www.googleapis.com/auth/userinfo.profile has been deprecated now. Please look at https://developers.google.com/+/api/auth-migration#timetable.

New scope you will be using to get profile info is: profile or https://www.googleapis.com/auth/plus.login

and the endpoint is - https://www.googleapis.com/plus/v1/people/{userId} - userId can be just 'me' for currently logged in user.

Gradle error: Minimum supported Gradle version is 3.3. Current version is 3.2

Error Message: Gradle sync failed: Minimum supported Gradle version is 4.9. Current version is 4.1-milestone-1. If using the gradle wrapper, try editing the distributionUrl in SampleProj/app/gradle/wrapper/gradle-wrapper.properties to gradle-4.9-all.zip

I am using Android studio IDE version 3.2 beta 2.

Solution: When we open gradle-wrapper.properties file in IDE it shows correct distributionUrl. but originally it has not been updated. So change the distributionUrl property manually.

Example : open a gradle-wrapper.properties file in notepad or any other editor. /Project/app/gradle/wrapper/gradle-wrapper.properties and change distributionUrl property to like this

distributionUrl=https\://services.gradle.org/distributions/gradle-4.9-all.zip

ExecuteNonQuery doesn't return results

What kind of query do you perform? Using ExecuteNonQuery is intended for UPDATE, INSERT and DELETE queries. As per the documentation:

For UPDATE, INSERT, and DELETE statements, the return value is the number of rows affected by the command. When a trigger exists on a table being inserted or updated, the return value includes the number of rows affected by both the insert or update operation and the number of rows affected by the trigger or triggers. For all other types of statements, the return value is -1.

How to check for an undefined or null variable in JavaScript?

If you try and reference an undeclared variable, an error will be thrown in all JavaScript implementations.

Properties of objects aren't subject to the same conditions. If an object property hasn't been defined, an error won't be thrown if you try and access it. So in this situation you could shorten:

 if (typeof(myObj.some_property) != "undefined" && myObj.some_property != null)

to

if (myObj.some_property != null)

With this in mind, and the fact that global variables are accessible as properties of the global object (window in the case of a browser), you can use the following for global variables:

if (window.some_variable != null) {
    // Do something with some_variable
}

In local scopes, it always useful to make sure variables are declared at the top of your code block, this will save on recurring uses of typeof.

Concat strings by & and + in VB.Net

& and + are both concatenation operators but when you specify an integer while using +, vb.net tries to cast "Hello" into integer to do an addition. If you change "Hello" with "123", you will get the result 124.