Programs & Examples On #Nodename

Kubernetes Pod fails with CrashLoopBackOff

I ran into the same error.

NAME         READY   STATUS             RESTARTS   AGE
pod/webapp   0/1     CrashLoopBackOff   5          47h

My problem was that I was trying to run two different pods with the same metadata name.

kind: Pod metadata: name: webapp labels: ...

To find all the names of your pods run: kubectl get pods

NAME         READY   STATUS    RESTARTS   AGE
webapp       1/1     Running   15         47h

then I changed the conflicting pod name and everything worked just fine.

NAME                 READY   STATUS    RESTARTS   AGE
webapp               1/1     Running   17         2d
webapp-release-0-5   1/1     Running   0          13m

get original element from ng-click

Not a direct answer to this question but rather to the "issue" of $event.currentTarget apparently be set to null.

This is due to the fact that console.log shows deep mutable objects at the last state of execution, not at the state when console.log was called.

You can check this for more information: Consecutive calls to console.log produce inconsistent results

How to fix getImageData() error The canvas has been tainted by cross-origin data?

My problem was so messed up I just base64 encoded the image to ensure there couldn't be any CORS issues

ssh: Could not resolve hostname [hostname]: nodename nor servname provided, or not known

Recently I came across the same issue. I was able to ssh to my pi on my network, but not from outside my home network.

I had already:

  • installed and tested ssh on my home network.
  • Set a static IP for my pi.
  • Set up a Dynamic DNS service and installed the software on my pi. I referenced these instructions for setting up the static ip, and there are many more instructional resources out there.

Also, I set up port forward on my router for hosting a web site and I had even port forward port 22 to my pi's static IP for ssh, but I left the field blank where you specify the application you are performing the port forwarding for on the router. Anyway, I added 'ssh' into this field and, VOILA! A working ssh connection from anywhere to my pi.

I'll write out my router's port forwarding settings.

(ApplicationTextField)_ssh     (external port)_22     (Internal Port)_22     (Protocal)_Both     (To IP Address)_192.168.1.###     (Enabled)_checkBox

Port forwarding settings can be different for different routers though, so look up directions for your router.

Now, when I am outside of my home network I connect to my pi by typing:

ssh pi@[hostname]

Then I am able to input my password and connect.

Console.log not working at all

Consider a more pragmatic approach to the question of "doing it correctly".

console.log("about to bind scroll fx");

$(window).scroll(function() {

       console.log("scroll bound, loop through div's");

       $('div').each(function(){

If both of those logs output correctly, then its likely the problem exists in your var declaration. To debug that, consider breaking it out into several lines:

var id='#'+$(this).attr('id');

console.log(id);

var off=$(id).offset().top;
var hei=$(id).height();
var winscroll=$(window).scrollTop();
var dif=hei+off-($(window).height());

By doing this, at least during debugging, you may find that the var id is undefined, causing errors throughout the rest of the code. Is it possible some of your div tags do not have id's?

IntelliJ, can't start simple web application: Unable to ping server at localhost:1099

I meet this question when i use intellij 15.0,then i update to 15.02 version. after that, I edit configurations and reset the Default JRE to my own JRE.It works well for me;

Using curl POST with variables defined in bash script functions

Putting data into a txt file worked for me

bash --version
GNU bash, version 4.2.46(2)-release (x86_64-redhat-linux-gnu)
curl --version
curl 7.29.0 (x86_64-redhat-linux-gnu)
 cat curl_data.txt 
 {  "type":"index-pattern", "excludeExportDetails": true  }

curl -X POST http://localhost:30560/api/saved_objects/_export -H 'kbn-xsrf: true' -H 'Content-Type: application/json' -d "$(cat curl_data.txt)" -o out.json

Loop through all elements in XML using NodeList

public class XMLParser {
   public static void main(String[] args){
      try {
         DocumentBuilder dBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
         Document doc = dBuilder.parse(new File("xml input"));
         NodeList nl=doc.getDocumentElement().getChildNodes();

         for(int k=0;k<nl.getLength();k++){
             printTags((Node)nl.item(k));
         }
      } catch (Exception e) {/*err handling*/}
   }

   public static void printTags(Node nodes){
       if(nodes.hasChildNodes()  || nodes.getNodeType()!=3){
           System.out.println(nodes.getNodeName()+" : "+nodes.getTextContent());
           NodeList nl=nodes.getChildNodes();
           for(int j=0;j<nl.getLength();j++)printTags(nl.item(j));
       }
   }
}

Recursively loop through and print out all the xml child tags in the document, in case you don't have to change the code to handle dynamic changes in xml, provided it's a well formed xml.

jQuery validate Uncaught TypeError: Cannot read property 'nodeName' of null

I had this problem in a Backbone project: my view contains a input and is re-rendered. Here is what happens (example for a checkbox):

  • The first render occurs;
  • jquery.validate is applied, adding an event onClick on the input;
  • View re-renders, the original input disappears but jquery.validate is still bound to it.

The solution is to update the input rather than re-render it completely. Here is an idea of the implementation:

var MyView = Backbone.View.extend({
    render: function(){
        if(this.rendered){
            this.update();
            return;
        }
        this.rendered = true;

        this.$el.html(tpl(this.model.toJSON()));
        return this;
    },
    update: function(){
        this.$el.find('input[type="checkbox"]').prop('checked', this.model.get('checked'));
        return this;
    }
});

This way you don't have to change any existing code calling render(), simply make sure update() keeps your HTML in sync and you're good to go.

How to create table using select query in SQL Server?

An example statement that uses a sub-select :

select * into MyNewTable
from
(
select 
  * 
from 
[SomeOtherTablename]
where 
  EventStartDatetime >= '01/JAN/2018' 
)
) mysourcedata
;

note that the sub query must be given a name .. any name .. e.g. above example gives the subquery a name of mysourcedata. Without this a syntax error is issued in SQL*server 2012.

The database should reply with a message like: (9999 row(s) affected)

What properties can I use with event.target?

//Do it like---
function dragStart(this_,event) {
    var row=$(this_).attr('whatever');
    event.dataTransfer.setData("Text", row);
}

How to inspect Javascript Objects

The for-in loops for each property in an object or array. You can use this property to get to the value as well as change it.

Note: Private properties are not available for inspection, unless you use a "spy"; basically, you override the object and write some code which does a for-in loop inside the object's context.

For in looks like:

for (var property in object) loop();

Some sample code:

function xinspect(o,i){
    if(typeof i=='undefined')i='';
    if(i.length>50)return '[MAX ITERATIONS]';
    var r=[];
    for(var p in o){
        var t=typeof o[p];
        r.push(i+'"'+p+'" ('+t+') => '+(t=='object' ? 'object:'+xinspect(o[p],i+'  ') : o[p]+''));
    }
    return r.join(i+'\n');
}

// example of use:
alert(xinspect(document));

Edit: Some time ago, I wrote my own inspector, if you're interested, I'm happy to share.

Edit 2: Well, I wrote one up anyway.

Get list of data-* attributes using javascript / jQuery

As mentioned above modern browsers have the The HTMLElement.dataset API.
That API gives you a DOMStringMap, and you can retrieve the list of data-* attributes simply doing:

var dataset = el.dataset; // as you asked in the question

you can also retrieve a array with the data- property's key names like

var data = Object.keys(el.dataset);

or map its values by

Object.keys(el.dataset).map(function(key){ return el.dataset[key];});
// or the ES6 way: Object.keys(el.dataset).map(key=>{ return el.dataset[key];});

and like this you can iterate those and use them without the need of filtering between all attributes of the element like we needed to do before.

getaddrinfo: nodename nor servname provided, or not known

I restarted my computer (Mac Mountain Lion) and the problem fixed itself. Something having to do with the shell thinking it was disconnected from the internet I think.

Restarting your shell in some definite way may solve this problem as well. Simply opening up a new session/window however did not work.

How to call a MySQL stored procedure from within PHP code?

You can call a stored procedure using the following syntax:

$result = mysql_query('CALL getNodeChildren(2)');

Executing <script> elements inserted with .innerHTML

scriptNode.innerHTML = code didn't work for IE. The only thing to do is replace with scriptNode.text = code and it work fine

Getting XML Node text value with Java DOM

If your XML goes quite deep, you might want to consider using XPath, which comes with your JRE, so you can access the contents far more easily using:

String text = xp.evaluate("//add[@job='351']/tag[position()=1]/text()", 
    document.getDocumentElement());

Full example:

import static org.junit.Assert.assertEquals;
import java.io.StringReader;    
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathFactory;    
import org.junit.Before;
import org.junit.Test;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;

public class XPathTest {

    private Document document;

    @Before
    public void setup() throws Exception {
        String xml = "<add job=\"351\"><tag>foobar</tag><tag>foobar2</tag></add>";
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = dbf.newDocumentBuilder();
        document = db.parse(new InputSource(new StringReader(xml)));
    }

    @Test
    public void testXPath() throws Exception {
        XPathFactory xpf = XPathFactory.newInstance();
        XPath xp = xpf.newXPath();
        String text = xp.evaluate("//add[@job='351']/tag[position()=1]/text()",
                document.getDocumentElement());
        assertEquals("foobar", text);
    }
}

numpy matrix vector multiplication

Simplest solution

Use numpy.dot or a.dot(b). See the documentation here.

>>> a = np.array([[ 5, 1 ,3], 
                  [ 1, 1 ,1], 
                  [ 1, 2 ,1]])
>>> b = np.array([1, 2, 3])
>>> print a.dot(b)
array([16, 6, 8])

This occurs because numpy arrays are not matrices, and the standard operations *, +, -, / work element-wise on arrays. Instead, you could try using numpy.matrix, and * will be treated like matrix multiplication.


Other Solutions

Also know there are other options:

  • As noted below, if using python3.5+ the @ operator works as you'd expect:

    >>> print(a @ b)
    array([16, 6, 8])
    
  • If you want overkill, you can use numpy.einsum. The documentation will give you a flavor for how it works, but honestly, I didn't fully understand how to use it until reading this answer and just playing around with it on my own.

    >>> np.einsum('ji,i->j', a, b)
    array([16, 6, 8])
    
  • As of mid 2016 (numpy 1.10.1), you can try the experimental numpy.matmul, which works like numpy.dot with two major exceptions: no scalar multiplication but it works with stacks of matrices.

    >>> np.matmul(a, b)
    array([16, 6, 8])
    
  • numpy.inner functions the same way as numpy.dot for matrix-vector multiplication but behaves differently for matrix-matrix and tensor multiplication (see Wikipedia regarding the differences between the inner product and dot product in general or see this SO answer regarding numpy's implementations).

    >>> np.inner(a, b)
    array([16, 6, 8])
    
    # Beware using for matrix-matrix multiplication though!
    >>> b = a.T
    >>> np.dot(a, b)
    array([[35,  9, 10],
           [ 9,  3,  4],
           [10,  4,  6]])
    >>> np.inner(a, b) 
    array([[29, 12, 19],
           [ 7,  4,  5],
           [ 8,  5,  6]])
    

Rarer options for edge cases

  • If you have tensors (arrays of dimension greater than or equal to one), you can use numpy.tensordot with the optional argument axes=1:

    >>> np.tensordot(a, b, axes=1)
    array([16,  6,  8])
    
  • Don't use numpy.vdot if you have a matrix of complex numbers, as the matrix will be flattened to a 1D array, then it will try to find the complex conjugate dot product between your flattened matrix and vector (which will fail due to a size mismatch n*m vs n).

Security of REST authentication schemes

Remember that your suggestions makes it difficult for clients to communicate with the server. They need to understand your innovative solution and encrypt the data accordingly, this model is not so good for public API (unless you are amazon\yahoo\google..).

Anyways, if you must encrypt the body content I would suggest you to check out existing standards and solutions like:

XML encryption (W3C standard)

XML Security

Amazon AWS Filezilla transfer permission denied

If you're using Ubuntu then use the following:

sudo chown -R ubuntu /var/www/html

sudo chmod -R 755 /var/www/html

How to remove a virtualenv created by "pipenv run"

I know that question is a bit old but

In root of project where Pipfile is located you could run

pipenv --venv

which returns

/Users/your_user_name/.local/share/virtualenvs/model-N-S4uBGU

and then remove this env by typing

rm -rf /Users/your_user_name/.local/share/virtualenvs/model-N-S4uBGU

How to define custom sort function in javascript?

or shorter

_x000D_
_x000D_
function sortBy(field) {_x000D_
  return function(a, b) {_x000D_
    return (a[field] > b[field]) - (a[field] < b[field])_x000D_
  };_x000D_
}_x000D_
_x000D_
let myArray = [_x000D_
    {tabid: 6237, url: 'https://reddit.com/r/znation'},_x000D_
    {tabid: 8430, url: 'https://reddit.com/r/soccer'},_x000D_
    {tabid: 1400, url: 'https://reddit.com/r/askreddit'},_x000D_
    {tabid: 3620, url: 'https://reddit.com/r/tacobell'},_x000D_
    {tabid: 5753, url: 'https://reddit.com/r/reddevils'},_x000D_
]_x000D_
_x000D_
myArray.sort(sortBy('url'));_x000D_
console.log(myArray);
_x000D_
_x000D_
_x000D_

Regular expression for a hexadecimal number?

If you're using Perl or PHP, you can replace

[0-9a-fA-F]

with:

[[:xdigit:]]

How to hide 'Back' button on navigation bar on iPhone?

Objective-C:
self.navigationItem.hidesBackButton = YES;

Swift:
navigationItem.hidesBackButton = true

Convert a float64 to an int in Go

If its simply from float64 to int, this should work

package main

import (
    "fmt"
)

func main() {
    nf := []float64{-1.9999, -2.0001, -2.0, 0, 1.9999, 2.0001, 2.0}

    //round
    fmt.Printf("Round : ")
    for _, f := range nf {
        fmt.Printf("%d ", round(f))
    }
    fmt.Printf("\n")

    //rounddown ie. math.floor
    fmt.Printf("RoundD: ")
    for _, f := range nf {
        fmt.Printf("%d ", roundD(f))
    }
    fmt.Printf("\n")

    //roundup ie. math.ceil
    fmt.Printf("RoundU: ")
    for _, f := range nf {
        fmt.Printf("%d ", roundU(f)) 
    }
    fmt.Printf("\n")

}

func roundU(val float64) int {
    if val > 0 { return int(val+1.0) }
    return int(val)
}

func roundD(val float64) int {
    if val < 0 { return int(val-1.0) }
    return int(val)
}

func round(val float64) int {
    if val < 0 { return int(val-0.5) }
    return int(val+0.5)
}

Outputs:

Round : -2 -2 -2 0 2 2 2 
RoundD: -2 -3 -3 0 1 2 2 
RoundU: -1 -2 -2 0 2 3 3 

Here's the code in the playground - https://play.golang.org/p/HmFfM6Grqh

How to make nginx to listen to server_name:port

The server_namedocs directive is used to identify virtual hosts, they're not used to set the binding.

netstat tells you that nginx listens on 0.0.0.0:80 which means that it will accept connections from any IP.

If you want to change the IP nginx binds on, you have to change the listendocs rule.
So, if you want to set nginx to bind to localhost, you'd change that to:

listen 127.0.0.1:80;

In this way, requests that are not coming from localhost are discarded (they don't even hit nginx).

How do I get the name of the current executable in C#?

System.AppDomain.CurrentDomain.FriendlyName

How to change port for jenkins window service when 8080 is being used

  1. Go to the directory where you installed Jenkins (by default, it's under Program Files/Jenkins)
  2. Open the Jenkins.xml configuration file
  3. Search --httpPort=8080 and replace the 8080 with the new port number that you wish
  4. Restart Jenkins for changes to take effect

How to add favicon.ico in ASP.NET site

Simply:

/favicon.ico

The leading slash is important.

How to set up Spark on Windows?

Here is a simple minimum script to run from any python console. It assumes that you have extracted the Spark libraries that you have downloaded into C:\Apache\spark-1.6.1.

This works in Windows without building anything and solves problems where Spark would complain about recursive pickling.

import sys
import os
spark_home = 'C:\Apache\spark-1.6.1'

sys.path.insert(0, os.path.join(spark_home, 'python'))
sys.path.insert(0, os.path.join(spark_home, 'python\lib\pyspark.zip')) 
sys.path.insert(0, os.path.join(spark_home, 'python\lib\py4j-0.9-src.zip')) 

# Start a spark context:
sc = pyspark.SparkContext()

# 
lines = sc.textFile(os.path.join(spark_home, "README.md")
pythonLines = lines.filter(lambda line: "Python" in line)
pythonLines.first()

AppStore - App status is ready for sale, but not in app store

After your app status changes to 'Ready for Sale' you will get official mail from Apple. The mail itself states that it might take 24 hours before your App is available on AppStore. If it takes more than days then contact Apple.

Refer below screenshot.

Screenshot

How do I bind Twitter Bootstrap tooltips to dynamically created elements?

I found a combination of these answers gave me the best outcome - allowing me to still position the tooltip and attach it to the relevant container:

$('body').on('mouseenter', '[rel=tooltip]', function(){
  var el = $(this);
  if (el.data('tooltip') === undefined) {
    el.tooltip({
      placement: el.data("placement") || "top",
      container: el.data("container") || false
    });
  }
  el.tooltip('show');
});

$('body').on('mouseleave', '[rel=tooltip]', function(){
  $(this).tooltip('hide');
});

Relevant HTML:

<button rel="tooltip" class="btn" data-placement="bottom" data-container=".some-parent" title="Show Tooltip">
    <i class="icon-some-icon"></i>
</button>

What is the most effective way for float and double comparison?

The portable way to get epsilon in C++ is

#include <limits>
std::numeric_limits<double>::epsilon()

Then the comparison function becomes

#include <cmath>
#include <limits>

bool AreSame(double a, double b) {
    return std::fabs(a - b) < std::numeric_limits<double>::epsilon();
}

How to list the properties of a JavaScript object?

Mozilla has full implementation details on how to do it in a browser where it isn't supported, if that helps:

if (!Object.keys) {
  Object.keys = (function () {
    var hasOwnProperty = Object.prototype.hasOwnProperty,
        hasDontEnumBug = !({toString: null}).propertyIsEnumerable('toString'),
        dontEnums = [
          'toString',
          'toLocaleString',
          'valueOf',
          'hasOwnProperty',
          'isPrototypeOf',
          'propertyIsEnumerable',
          'constructor'
        ],
        dontEnumsLength = dontEnums.length;

    return function (obj) {
      if (typeof obj !== 'object' && typeof obj !== 'function' || obj === null) throw new TypeError('Object.keys called on non-object');

      var result = [];

      for (var prop in obj) {
        if (hasOwnProperty.call(obj, prop)) result.push(prop);
      }

      if (hasDontEnumBug) {
        for (var i=0; i < dontEnumsLength; i++) {
          if (hasOwnProperty.call(obj, dontEnums[i])) result.push(dontEnums[i]);
        }
      }
      return result;
    };
  })();
}

You could include it however you'd like, but possibly in some kind of extensions.js file at the top of your script stack.

numpy.where() detailed, step-by-step explanation / examples

After fiddling around for a while, I figured things out, and am posting them here hoping it will help others.

Intuitively, np.where is like asking "tell me where in this array, entries satisfy a given condition".

>>> a = np.arange(5,10)
>>> np.where(a < 8)       # tell me where in a, entries are < 8
(array([0, 1, 2]),)       # answer: entries indexed by 0, 1, 2

It can also be used to get entries in array that satisfy the condition:

>>> a[np.where(a < 8)] 
array([5, 6, 7])          # selects from a entries 0, 1, 2

When a is a 2d array, np.where() returns an array of row idx's, and an array of col idx's:

>>> a = np.arange(4,10).reshape(2,3)
array([[4, 5, 6],
       [7, 8, 9]])
>>> np.where(a > 8)
(array(1), array(2))

As in the 1d case, we can use np.where() to get entries in the 2d array that satisfy the condition:

>>> a[np.where(a > 8)] # selects from a entries 0, 1, 2

array([9])


Note, when a is 1d, np.where() still returns an array of row idx's and an array of col idx's, but columns are of length 1, so latter is empty array.

Unbound classpath container in Eclipse

I had a similar problem when I recreated my workspace that was fixed in the following way:

Go to Eclipse -> Preferences, under Java select "Installed JREs" and check one of the boxes to specify a default JRE. Click OK and then go back to your project's properties. Go to the "Java Build Path" section and choose the "Libraries" tab. Remove the unbound System Default library, then click the "Add Library" button. Select "JRE System Library" and you should be good to go!

Python not working in the command line of git bash

if you run a Windows PowerShell command and an error occurs, the error record will be appended to the “automatic variable” named $error.

You can use the $error variable to find the errors, in the same PowerShell session.

The $Error variable holds a collection of information, and that’s why using $Error[0] can get to your error message objects. Also the $Error[0] variable will hold the last error message encountered until the PowerShell session ends.

Generating a SHA-256 hash from the Linux command line

For the sha256 hash in base64, use:

echo -n foo | openssl dgst -binary -sha1 | openssl base64

Example

echo -n foo | openssl dgst -binary -sha1 | openssl base64
C+7Hteo/D9vJXQ3UfzxbwnXaijM=

Pass a reference to DOM object with ng-click

The angular way is shown in the angular docs :)

https://docs.angularjs.org/api/ng/directive/ngReadonly

Here is the example they use:

<body>
    Check me to make text readonly: <input type="checkbox" ng-model="checked"><br/>
    <input type="text" ng-readonly="checked" value="I'm Angular"/>
</body>

Basically the angular way is to create a model object that will hold whether or not the input should be readonly and then set that model object accordingly. The beauty of angular is that most of the time you don't need to do any dom manipulation. You just have angular render the view they way your model is set (let angular do the dom manipulation for you and keep your code clean).

So basically in your case you would want to do something like below or check out this working example.

<button ng-click="isInput1ReadOnly = !isInput1ReadOnly">Click Me</button>
<input type="text" ng-readonly="isInput1ReadOnly" value="Angular Rules!"/>

How to generate serial version UID in Intellij

Without any plugins:

You just need to enable highlight: (Idea v.2016, 2017 and 2018, previous versions may have same or similar settings)

File -> Settings -> Editor -> Inspections -> Java -> Serialization issues -> Serializable class without 'serialVersionUID' - set flag and click 'OK'. (For Macs, Settings is under IntelliJ IDEA -> Preferences...)

Now, if your class implements Serializable, you will see highlight and alt+Enter on class name will ask you to generate private static final long serialVersionUID.

UPD: a faster way to find this setting - you might use hotkey Ctrl+Shift+A (find action), type Serializable class without 'serialVersionUID' - the first is the one.

Is it possible to install both 32bit and 64bit Java on Windows 7?

To install 32-bit Java on Windows 7 (64-bit OS + Machine). You can do:

1) Download JDK: http://javadl.sun.com/webapps/download/AutoDL?BundleId=58124
2) Download JRE: http://www.java.com/en/download/installed.jsp?jre_version=1.6.0_22&vendor=Sun+Microsystems+Inc.&os=Linux&os_version=2.6.41.4-1.fc15.i686

3) System variable create: C:\program files (x86)\java\jre6\bin\

4) Anywhere you type java -version

it use 32-bit on (64-bit). I have to use this because lots of third party libraries do not work with 64-bit. Java wake up from the hell, give us peach :P. Go-language is killer.

Sending Multipart File as POST parameters with RestTemplate requests

A way to solve this without needing to use a FileSystemResource that requires a file on disk, is to use a ByteArrayResource, that way you can send a byte array in your post (this code works with Spring 3.2.3):

MultiValueMap<String, Object> map = new LinkedMultiValueMap<String, Object>();
final String filename="somefile.txt";
map.add("name", filename);
map.add("filename", filename);
ByteArrayResource contentsAsResource = new ByteArrayResource(content.getBytes("UTF-8")){
            @Override
            public String getFilename(){
                return filename;
            }
        };
map.add("file", contentsAsResource);
String result = restTemplate.postForObject(urlForFacade, map, String.class);

I override the getFilename of the ByteArrayResource because if I don't I get a null pointer exception (apparently it depends on whether the java activation .jar is on the classpath, if it is, it will use the file name to try to determine the content type)

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

you can use transition in css3:

_x000D_
_x000D_
.carousel-fade .carousel-inner .item {_x000D_
  -webkit-transition-property: opacity;_x000D_
  transition-property: opacity;_x000D_
}_x000D_
.carousel-fade .carousel-inner .item,_x000D_
.carousel-fade .carousel-inner .active.left,_x000D_
.carousel-fade .carousel-inner .active.right {_x000D_
  opacity: 0;_x000D_
}_x000D_
.carousel-fade .carousel-inner .active,_x000D_
.carousel-fade .carousel-inner .next.left,_x000D_
.carousel-fade .carousel-inner .prev.right {_x000D_
  opacity: 1;_x000D_
}_x000D_
.carousel-fade .carousel-inner .next,_x000D_
.carousel-fade .carousel-inner .prev,_x000D_
.carousel-fade .carousel-inner .active.left,_x000D_
.carousel-fade .carousel-inner .active.right {_x000D_
  left: 0;_x000D_
  -webkit-transform: translate3d(0, 0, 0);_x000D_
          transform: translate3d(0, 0, 0);_x000D_
}_x000D_
.carousel-fade .carousel-control {_x000D_
  z-index: 2;_x000D_
}
_x000D_
_x000D_
_x000D_

Error :The remote server returned an error: (401) Unauthorized

Shouldn't you be providing the credentials for your site, instead of passing the DefaultCredentials?

Something like request.Credentials = new NetworkCredential("UserName", "PassWord");

Also, remove request.UseDefaultCredentials = true; request.PreAuthenticate = true;

How to remove multiple indexes from a list at the same time?

Old question, but I have an answer.

First, peruse the elements of the list like so:

for x in range(len(yourlist)):
    print '%s: %s' % (x, yourlist[x])

Then, call this function with a list of the indexes of elements you want to pop. It's robust enough that the order of the list doesn't matter.

def multipop(yourlist, itemstopop):
    result = []
    itemstopop.sort()
    itemstopop = itemstopop[::-1]
    for x in itemstopop:
        result.append(yourlist.pop(x))
    return result

As a bonus, result should only contain elements you wanted to remove.

In [73]: mylist = ['a','b','c','d','charles']

In [76]: for x in range(len(mylist)):

      mylist[x])

....:

0: a

1: b

2: c

3: d

4: charles

...

In [77]: multipop(mylist, [0, 2, 4])

Out[77]: ['charles', 'c', 'a']

...

In [78]: mylist

Out[78]: ['b', 'd']

How to run Tensorflow on CPU

For me, only setting CUDA_VISIBLE_DEVICES to precisely -1 works:

Works:

import os
import tensorflow as tf

os.environ['CUDA_VISIBLE_DEVICES'] = '-1'

if tf.test.gpu_device_name():
    print('GPU found')
else:
    print("No GPU found")

# No GPU found

Does not work:

import os
import tensorflow as tf

os.environ['CUDA_VISIBLE_DEVICES'] = ''    

if tf.test.gpu_device_name():
    print('GPU found')
else:
    print("No GPU found")

# GPU found

MySQL DISTINCT on a GROUP_CONCAT()

DISTINCT: will gives you unique values.

SELECT GROUP_CONCAT(DISTINCT(categories )) AS categories FROM table

How to deploy a React App on Apache web server

As well described in React's official docs, If you use routers that use the HTML5 pushState history API under the hood, you just need to below content to .htaccess file in public directory of your react-app.

Options -MultiViews
    RewriteEngine On
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteRule ^ index.html [QSA,L]

And if using relative path update the package.json like this:

"homepage": ".",

Note: If you are using react-router@^4, you can root <Link> using the basename prop on any <Router>.

import React from 'react';
import BrowserRouter as Router from 'react-router-dom';
...
<Router basename="/calendar"/>
<Link to="/today"/>

How to convert IPython notebooks to PDF and HTML?

notebook-as-pdfInstall

python -m pip install notebook-as-pdf pyppeteer-install

Use it

You can also use it with nbconvert:

jupyter-nbconvert --to PDFviaHTML filename.ipynb

which will create a file called filename.pdf.

or pip install notebook-as-pdf

create pdf from notebook jupyter-nbconvert-toPDFviaHTML

how to query for a list<String> in jdbctemplate

You can't use placeholders for column names, table names, data type names, or basically anything that isn't data.

Make the image go behind the text and keep it in center using CSS

Try this code:

body {z-index:0}
img.center {z-index:-1; margin-left:auto; margin-right:auto}

Setting the left & right margins to auto should center your image.

vi/vim editor, copy a block (not usual action)

just use V to select lines or v to select chars or Ctrlv to select a block.

When the selection spans the area you'd like to copy just hit y and use p to paste it anywhere you like...

Access-Control-Allow-Origin and Angular.js $http

Adding below to server.js resolved mine

    server.post('/your-rest-endpt/*', function(req,res){
    console.log('');
    console.log('req.url: '+req.url);
    console.log('req.headers: ');   
    console.dir(req.headers);
    console.log('req.body: ');
    console.dir(req.body);  

    var options = {
        host: 'restAPI-IP' + ':' + '8080'

        , protocol: 'http'
        , pathname: 'your-rest-endpt/'
    };
    console.log('options: ');
    console.dir(options);   

    var reqUrl = url.format(options);
    console.log("Forward URL: "+reqUrl);

    var parsedUrl = url.parse(req.url, true);
    console.log('parsedUrl: ');
    console.dir(parsedUrl);

    var queryParams = parsedUrl.query;

    var path = parsedUrl.path;
    var substr = path.substring(path.lastIndexOf("rest/"));
    console.log('substr: ');
    console.dir(substr);

    reqUrl += substr;
    console.log("Final Forward URL: "+reqUrl);

    var newHeaders = {
    };

    //Deep-copy it, clone it, but not point to me in shallow way...
    for (var headerKey in req.headers) {
        newHeaders[headerKey] = req.headers[headerKey];
    };

    var newBody = (req.body == null || req.body == undefined ? {} : req.body);

    if (newHeaders['Content-type'] == null
            || newHeaders['Content-type'] == undefined) {
        newHeaders['Content-type'] = 'application/json';
        newBody = JSON.stringify(newBody);
    }

    var requestOptions = {
        headers: {
            'Content-type': 'application/json'
        }
        ,body: newBody
        ,method: 'POST'
    };

    console.log("server.js : routes to URL : "+ reqUrl);

    request(reqUrl, requestOptions, function(error, response, body){
        if(error) {
            console.log('The error from Tomcat is --> ' + error.toString());
            console.dir(error);
            //return false;
        }

        if (response.statusCode != null 
                && response.statusCode != undefined
                && response.headers != null
                && response.headers != undefined) {
            res.writeHead(response.statusCode, response.headers);
        } else {
            //404 Not Found
            res.writeHead(404);         
        }
        if (body != null
                && body != undefined) {

            res.write(body);            
        }
        res.end();
    });
});

Finding non-numeric rows in dataframe in pandas?

Sorry about the confusion, this should be the correct approach. Do you want only to capture 'bad' only, not things like 'good'; Or just any non-numerical values?

In[15]:
np.where(np.any(np.isnan(df.convert_objects(convert_numeric=True)), axis=1))
Out[15]:
(array([3]),)

Java - how do I write a file to a specified directory

Just put the full directory location in the File object.

File file = new File("z:\\results.txt");

TypeError: 'function' object is not subscriptable - Python

You have two objects both named bank_holiday -- one a list and one a function. Disambiguate the two.

bank_holiday[month] is raising an error because Python thinks bank_holiday refers to the function (the last object bound to the name bank_holiday), whereas you probably intend it to mean the list.

while installing vc_redist.x64.exe, getting error "Failed to configure per-machine MSU package."

Posting answer to my own question as I found it here and was hidden in bottom somewhere -

https://social.msdn.microsoft.com/Forums/vstudio/en-US/64baed8c-b00c-40d5-b19a-99b26a11516e/visual-c-redistributable-for-visual-studio-2015-rc-fails-on-windows-server-2012?forum=vssetup

This is because the OS failed to install the required update Windows8.1-KB2999226-x64.msu.

However, you can install it by extracting that update to a folder (e.g. XXXX), and execute following cmdlet. You can find the Windows8.1-KB2999226-x64.msu at below.

C:\ProgramData\Package Cache\469A82B09E217DDCF849181A586DF1C97C0C5C85\packages\Patch\amd64\Windows8.1-KB2999226-x64.msu

copy this file to a folder you like, and

Create a folder XXXX in that and execute following commands from Admin command propmt

wusa.exe Windows8.1-KB2999226-x64.msu /extract:XXXX

DISM.exe /Online /Add-Package /PackagePath:XXXX\Windows8.1-KB2999226-x64.cab

vc_redist.x64.exe /repair

(last command need not be run. Just execute vc_redist.x64.exe once again)

this worked for me.

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

By default, Homebrew installs packages to your /usr/local. Macport commands require sudo to install and upgrade (similar to apt-get in Ubuntu).

For more detail:

This site suggests using Hombrew: http://deephill.com/macports-vs-homebrew/

whereas this site lists the advantages of using Macports: http://arstechnica.com/civis/viewtopic.php?f=19&t=1207907

I also switched from Ubuntu recently, and I enjoy using homebrew (it's simple and easy to use!), but if you feel attached to using sudo, Macports might be the better way to go!

Android - Start service on boot

I've had success without the full package, do you know where the call chain is getting interrupted? If you debug with Log()'s, at what point does it no longer work?

I think it may be in your IntentService, this all looks fine.

How to tell if a JavaScript function is defined

Try:

if (typeof(callback) == 'function')

Why I've got no crontab entry on OS X when using vim?

Use another text editor

env EDITOR=nano crontab -e 

or

env EDITOR=code crontab -e 

How to give Jenkins more heap space when it´s started as a service under Windows?

In your Jenkins installation directory there is a jenkins.xml, where you can set various options. Add the parameter -Xmx with the size you want to the arguments-tag (or increase the size if its already there).

How to delete files older than X hours

If you do not have "-mmin" in your version of "find", then "-mtime -0.041667" gets pretty close to "within the last hour", so in your case, use:

-mtime +(X * 0.041667)

so, if X means 6 hours, then:

find . -mtime +0.25 -ls

works because 24 hours * 0.25 = 6 hours

Jar mismatch! Fix your dependencies

  1. Jar mismatch comes when you use library projects in your application and both projects are using same jar with different version so just check all library projects attached in your application. if some mismatch exist then remove it.

  2. if above process is not working then just do remove project dependency from build path and again add library projects and build the application.

What is the difference between document.location.href and document.location?

The document.location is an object that contains properties for the current location.

The href property is one of these properties, containing the complete URL, i.e. all the other properties put together.

Some browsers allow you to assign an URL to the location object and acts as if you assigned it to the href property. Some other browsers are more picky, and requires you to use the href property. Thus, to make the code work in all browsers, you have to use the href property.

Both the window and document objects has a location object. You can set the URL using either window.location.href or document.location.href. However, logically the document.location object should be read-only (as you can't change the URL of a document; changing the URL loads a new document), so to be on the safe side you should rather use window.location.href when you want to set the URL.

Traits vs. interfaces

Public Service Announcement:

I want to state for the record that I believe traits are almost always a code smell and should be avoided in favor of composition. It's my opinion that single inheritance is frequently abused to the point of being an anti-pattern and multiple inheritance only compounds this problem. You'll be much better served in most cases by favoring composition over inheritance (be it single or multiple). If you're still interested in traits and their relationship to interfaces, read on ...


Let's start by saying this:

Object-Oriented Programming (OOP) can be a difficult paradigm to grasp. Just because you're using classes doesn't mean your code is Object-Oriented (OO).

To write OO code you need to understand that OOP is really about the capabilities of your objects. You've got to think about classes in terms of what they can do instead of what they actually do. This is in stark contrast to traditional procedural programming where the focus is on making a bit of code "do something."

If OOP code is about planning and design, an interface is the blueprint and an object is the fully constructed house. Meanwhile, traits are simply a way to help build the house laid out by the blueprint (the interface).

Interfaces

So, why should we use interfaces? Quite simply, interfaces make our code less brittle. If you doubt this statement, ask anyone who's been forced to maintain legacy code that wasn't written against interfaces.

The interface is a contract between the programmer and his/her code. The interface says, "As long as you play by my rules you can implement me however you like and I promise I won't break your other code."

So as an example, consider a real-world scenario (no cars or widgets):

You want to implement a caching system for a web application to cut down on server load

You start out by writing a class to cache request responses using APC:

class ApcCacher
{
  public function fetch($key) {
    return apc_fetch($key);
  }
  public function store($key, $data) {
    return apc_store($key, $data);
  }
  public function delete($key) {
    return apc_delete($key);
  }
}

Then, in your HTTP response object, you check for a cache hit before doing all the work to generate the actual response:

class Controller
{
  protected $req;
  protected $resp;
  protected $cacher;

  public function __construct(Request $req, Response $resp, ApcCacher $cacher=NULL) {
    $this->req    = $req;
    $this->resp   = $resp;
    $this->cacher = $cacher;

    $this->buildResponse();
  }

  public function buildResponse() {
    if (NULL !== $this->cacher && $response = $this->cacher->fetch($this->req->uri()) {
      $this->resp = $response;
    } else {
      // Build the response manually
    }
  }

  public function getResponse() {
    return $this->resp;
  }
}

This approach works great. But maybe a few weeks later you decide you want to use a file-based cache system instead of APC. Now you have to change your controller code because you've programmed your controller to work with the functionality of the ApcCacher class rather than to an interface that expresses the capabilities of the ApcCacher class. Let's say instead of the above you had made the Controller class reliant on a CacherInterface instead of the concrete ApcCacher like so:

// Your controller's constructor using the interface as a dependency
public function __construct(Request $req, Response $resp, CacherInterface $cacher=NULL)

To go along with that you define your interface like so:

interface CacherInterface
{
  public function fetch($key);
  public function store($key, $data);
  public function delete($key);
}

In turn you have both your ApcCacher and your new FileCacher classes implement the CacherInterface and you program your Controller class to use the capabilities required by the interface.

This example (hopefully) demonstrates how programming to an interface allows you to change the internal implementation of your classes without worrying if the changes will break your other code.

Traits

Traits, on the other hand, are simply a method for re-using code. Interfaces should not be thought of as a mutually exclusive alternative to traits. In fact, creating traits that fulfill the capabilities required by an interface is the ideal use case.

You should only use traits when multiple classes share the same functionality (likely dictated by the same interface). There's no sense in using a trait to provide functionality for a single class: that only obfuscates what the class does and a better design would move the trait's functionality into the relevant class.

Consider the following trait implementation:

interface Person
{
    public function greet();
    public function eat($food);
}

trait EatingTrait
{
    public function eat($food)
    {
        $this->putInMouth($food);
    }

    private function putInMouth($food)
    {
        // Digest delicious food
    }
}

class NicePerson implements Person
{
    use EatingTrait;

    public function greet()
    {
        echo 'Good day, good sir!';
    }
}

class MeanPerson implements Person
{
    use EatingTrait;

    public function greet()
    {
        echo 'Your mother was a hamster!';
    }
}

A more concrete example: imagine both your FileCacher and your ApcCacher from the interface discussion use the same method to determine whether a cache entry is stale and should be deleted (obviously this isn't the case in real life, but go with it). You could write a trait and allow both classes to use it to for the common interface requirement.

One final word of caution: be careful not to go overboard with traits. Often traits are used as a crutch for poor design when unique class implementations would suffice. You should limit traits to fulfilling interface requirements for best code design.

How to enable zoom controls and pinch zoom in a WebView?

To enable zoom controls in a WebView, add the following line:

webView.getSettings().setBuiltInZoomControls(true);

With this line of code, you get the zoom enabled in your WebView, if you want to remove the zoom in and zoom out buttons provided, add the following line of code:

webView.getSettings().setDisplayZoomControls(false);

Excel VBA, error 438 "object doesn't support this property or method

The Error is here

lastrow = wsPOR.Range("A" & Rows.Count).End(xlUp).Row + 1

wsPOR is a workbook and not a worksheet. If you are working with "Sheet1" of that workbook then try this

lastrow = wsPOR.Sheets("Sheet1").Range("A" & _
          wsPOR.Sheets("Sheet1").Rows.Count).End(xlUp).Row + 1

Similarly

wsPOR.Range("A2:G" & lastrow).Select

should be

wsPOR.Sheets("Sheet1").Range("A2:G" & lastrow).Select

Rails: Can't verify CSRF token authenticity when making a POST request

Cross site request forgery (CSRF/XSRF) is when a malicious web page tricks users into performing a request that is not intended for example by using bookmarklets, iframes or just by creating a page which is visually similar enough to fool users.

The Rails CSRF protection is made for "classical" web apps - it simply gives a degree of assurance that the request originated from your own web app. A CSRF token works like a secret that only your server knows - Rails generates a random token and stores it in the session. Your forms send the token via a hidden input and Rails verifies that any non GET request includes a token that matches what is stored in the session.

However an API is usually by definition cross site and meant to be used in more than your web app, which means that the whole concept of CSRF does not quite apply.

Instead you should use a token based strategy of authenticating API requests with an API key and secret since you are verifying that the request comes from an approved API client - not from your own app.

You can deactivate CSRF as pointed out by @dcestari:

class ApiController < ActionController::Base
  protect_from_forgery with: :null_session
end

Updated. In Rails 5 you can generate API only applications by using the --api option:

rails new appname --api

They do not include the CSRF middleware and many other components that are superflouus.

jquery input select all on focus

This would do the work and avoid the issue that you can no longer select part of the text by mouse.

$("input[type=text]").click(function() {
    if(!$(this).hasClass("selected")) {
        $(this).select();
        $(this).addClass("selected");
    }
});
$("input[type=text]").blur(function() {
    if($(this).hasClass("selected")) {
        $(this).removeClass("selected");
    }
});

How to export a CSV to Excel using Powershell

I found this while passing and looking for answers on how to compile a set of csvs into a single excel doc with the worksheets (tabs) named after the csv files. It is a nice function. Sadly, I cannot run them on my network :( so i do not know how well it works.

Function Release-Ref ($ref)
{
    ([System.Runtime.InteropServices.Marshal]::ReleaseComObject(
    [System.__ComObject]$ref) -gt 0)
    [System.GC]::Collect()
    [System.GC]::WaitForPendingFinalizers()
    }
    Function ConvertCSV-ToExcel
    {
    <#
    .SYNOPSIS
    Converts     one or more CSV files into an excel file.
    
    .DESCRIPTION
    Converts one or more CSV files into an excel file. Each CSV file is imported into its own worksheet with the name of the
    file being the name of the worksheet.
        
    .PARAMETER inputfile
    Name of the CSV file being converted
    
    .PARAMETER output
    Name of the converted excel file
    
    .EXAMPLE
    Get-ChildItem *.csv | ConvertCSV-ToExcel -output ‘report.xlsx’
    
    .EXAMPLE
    ConvertCSV-ToExcel -inputfile ‘file.csv’ -output ‘report.xlsx’
    
    .EXAMPLE
    ConvertCSV-ToExcel -inputfile @(“test1.csv”,”test2.csv”) -output ‘report.xlsx’
    
    .NOTES
    Author:     Boe Prox
    Date Created: 01SEPT210
    Last Modified:
    
    #>
    
    #Requires -version 2.0
    [CmdletBinding(
    SupportsShouldProcess = $True,
    ConfirmImpact = ‘low’,
    DefaultParameterSetName = ‘file’
    )]
    Param (
    [Parameter(
    ValueFromPipeline=$True,
    Position=0,
    Mandatory=$True,
    HelpMessage=”Name of CSV/s to import”)]
    [ValidateNotNullOrEmpty()]
    [array]$inputfile,
    [Parameter(
    ValueFromPipeline=$False,
    Position=1,
    Mandatory=$True,
    HelpMessage=”Name of excel file output”)]
    [ValidateNotNullOrEmpty()]
    [string]$output
    )
    
    Begin {
    #Configure regular expression to match full path of each file
    [regex]$regex = “^\w\:\\”
    
    #Find the number of CSVs being imported
    $count = ($inputfile.count -1)
    
    #Create Excel Com Object
    $excel = new-object -com excel.application
    
    #Disable alerts
    $excel.DisplayAlerts = $False
    
    #Show Excel application
    $excel.V    isible = $False
    
    #Add workbook
    $workbook = $excel.workbooks.Add()
    
    #Remove other worksheets
    $workbook.worksheets.Item(2).delete()
    #After the first worksheet is removed,the next one takes its place
    $workbook.worksheets.Item(2).delete()
    
    #Define initial worksheet number
    $i = 1
    }
    
    Process {
    ForEach ($input in $inputfile) {
    #If more than one file, create another worksheet for each file
    If ($i -gt 1) {
    $workbook.worksheets.Add() | Out-Null
    }
    #Use the first worksheet in the workbook (also the newest created worksheet is always 1)
    $worksheet = $workbook.worksheets.Item(1)
    #Add name of CSV as worksheet name
    $worksheet.name = “$((GCI $input).basename)”
    
    #Open the CSV file in Excel, must be converted into complete path if no already done
    If ($regex.ismatch($input)) {
    $tempcsv = $excel.Workbooks.Open($input)
    }
    ElseIf ($regex.ismatch(“$($input.fullname)”)) {
    $tempcsv = $excel.Workbooks.Open(“$($input.fullname)”)
    }
    Else {
    $tempcsv = $excel.Workbooks.Open(“$($pwd)\$input”)
    }
    $tempsheet = $tempcsv.Worksheets.Item(1)
    #Copy contents of the CSV file
    $tempSheet.UsedRange.Copy() | Out-Null
    #Paste contents of CSV into existing workbook
    $worksheet.Paste()
    
    #Close temp workbook
    $tempcsv.close()
    
    #Select all used cells
    $range = $worksheet.UsedRange
    
    #Autofit the columns
    $range.EntireColumn.Autofit() | out-null
    $i++
    }
    }
    
    End {
    #Save spreadsheet
    $workbook.saveas(“$pwd\$output”)
    
    Write-Host -Fore Green “File saved to $pwd\$output”
    
    #Close Excel
    $excel.quit()
    
    #Release processes for Excel
    $a = Release-Ref($range)
    }
}

How to return an array from a function?

how can i return a array in a c++ method and how must i declare it? int[] test(void); ??

This sounds like a simple question, but in C++ you have quite a few options. Firstly, you should prefer...

  • std::vector<>, which grows dynamically to however many elements you encounter at runtime, or

  • std::array<> (introduced with C++11), which always stores a number of elements specified at compile time,

...as they manage memory for you, ensuring correct behaviour and simplifying things considerably:

std::vector<int> fn()
{
    std::vector<int> x;
    x.push_back(10);
    return x;
}

std::array<int, 2> fn2()  // C++11
{
    return {3, 4};
}

void caller()
{
    std::vector<int> a = fn();
    const std::vector<int>& b = fn(); // extend lifetime but read-only
                                      // b valid until scope exit/return

    std::array<int, 2> c = fn2();
    const std::array<int, 2>& d = fn2();
}

The practice of creating a const reference to the returned data can sometimes avoid a copy, but normally you can just rely on Return Value Optimisation, or - for vector but not array - move semantics (introduced with C++11).

If you really want to use an inbuilt array (as distinct from the Standard library class called array mentioned above), one way is for the caller to reserve space and tell the function to use it:

void fn(int x[], int n)
{
    for (int i = 0; i < n; ++i)
        x[i] = n;
}

void caller()
{
    // local space on the stack - destroyed when caller() returns
    int x[10];
    fn(x, sizeof x / sizeof x[0]);

    // or, use the heap, lives until delete[](p) called...
    int* p = new int[10];
    fn(p, 10);
}

Another option is to wrap the array in a structure, which - unlike raw arrays - are legal to return by value from a function:

struct X
{
    int x[10];
};

X fn()
{
    X x;
    x.x[0] = 10;
    // ...
    return x;
}

void caller()
{
    X x = fn();
}

Starting with the above, if you're stuck using C++03 you might want to generalise it into something closer to the C++11 std::array:

template <typename T, size_t N>
struct array
{
    T& operator[](size_t n) { return x[n]; }
    const T& operator[](size_t n) const { return x[n]; }
    size_t size() const { return N; }
    // iterators, constructors etc....
  private:
    T x[N];
};

Another option is to have the called function allocate memory on the heap:

int* fn()
{
    int* p = new int[2];
    p[0] = 0;
    p[1] = 1;
    return p;
}

void caller()
{
    int* p = fn();
    // use p...
    delete[] p;
}

To help simplify the management of heap objects, many C++ programmers use "smart pointers" that ensure deletion when the pointer(s) to the object leave their scopes. With C++11:

std::shared_ptr<int> p(new int[2], [](int* p) { delete[] p; } );
std::unique_ptr<int[]> p(new int[3]);

If you're stuck on C++03, the best option is to see if the boost library is available on your machine: it provides boost::shared_array.

Yet another option is to have some static memory reserved by fn(), though this is NOT THREAD SAFE, and means each call to fn() overwrites the data seen by anyone keeping pointers from previous calls. That said, it can be convenient (and fast) for simple single-threaded code.

int* fn(int n)
{
    static int x[2];  // clobbered by each call to fn()
    x[0] = n;
    x[1] = n + 1;
    return x;  // every call to fn() returns a pointer to the same static x memory
}

void caller()
{
    int* p = fn(3);
    // use p, hoping no other thread calls fn() meanwhile and clobbers the values...
    // no clean up necessary...
}

How to Debug Variables in Smarty like in PHP var_dump()

Try out with the Smarty Session:

{$smarty.session|@debug_print_var}

or

{$smarty.session|@print_r}

To beautify your output, use it between <pre> </pre> tags

DataGridView changing cell background color

Simply create a new DataGridViewCellStyle object, set its back color and then assign the cell's style to it:

    DataGridViewCellStyle style = new DataGridViewCellStyle();
    style.BackColor = Color.FromArgb(((GesTest.dsEssais.FMstatusAnomalieRow)row.DataBoundItem).iColor);
    style.ForeColor = Color.Black;
    row.Cells[color.Index].Style = style;

Combine a list of data frames into one data frame by row

There is also bind_rows(x, ...) in dplyr.

> system.time({ df.Base <- do.call("rbind", listOfDataFrames) })
   user  system elapsed 
   0.08    0.00    0.07 
> 
> system.time({ df.dplyr <- as.data.frame(bind_rows(listOfDataFrames)) })
   user  system elapsed 
   0.01    0.00    0.02 
> 
> identical(df.Base, df.dplyr)
[1] TRUE

Given URL is not permitted by the application configuration

Sometimes this error occurs for old javascript sdk. If you save locally javascript file. Update it. I prefer to load it form the facebook server all the time.

Turning off some legends in a ggplot

You can use guide=FALSE in scale_..._...() to suppress legend.

For your example you should use scale_colour_continuous() because length is continuous variable (not discrete).

(p3 <- ggplot(mov, aes(year, rating, colour = length, shape = mpaa)) +
   scale_colour_continuous(guide = FALSE) +
   geom_point()
)

Or using function guides() you should set FALSE for that element/aesthetic that you don't want to appear as legend, for example, fill, shape, colour.

p0 <- ggplot(mov, aes(year, rating, colour = length, shape = mpaa)) +
  geom_point()    
p0+guides(colour=FALSE)

UPDATE

Both provided solutions work in new ggplot2 version 2.0.0 but movies dataset is no longer present in this library. Instead you have to use new package ggplot2movies to check those solutions.

library(ggplot2movies)
data(movies)
mov <- subset(movies, length != "")

Including a groovy script in another groovy

For late-comers, it appears that groovy now support the :load file-path command which simply redirects input from the given file, so it is now trivial to include library scripts.

It works as input to the groovysh & as a line in a loaded file:
groovy:000> :load file1.groovy

file1.groovy can contain:
:load path/to/another/file invoke_fn_from_file();

Reading inputStream using BufferedReader.readLine() is too slow

I have a longer test to try. This takes an average of 160 ns to read each line as add it to a List (Which is likely to be what you intended as dropping the newlines is not very useful.

public static void main(String... args) throws IOException {
    final int runs = 5 * 1000 * 1000;

    final ServerSocket ss = new ServerSocket(0);
    new Thread(new Runnable() {
        @Override
        public void run() {
            try {
                Socket serverConn = ss.accept();
                String line = "Hello World!\n";
                BufferedWriter br = new BufferedWriter(new OutputStreamWriter(serverConn.getOutputStream()));
                for (int count = 0; count < runs; count++)
                    br.write(line);
                serverConn.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }).start();

    Socket conn = new Socket("localhost", ss.getLocalPort());

    long start = System.nanoTime();
    BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String line;

    List<String> responseData = new ArrayList<String>();
    while ((line = in.readLine()) != null) {
        responseData.add(line);
    }
    long time = System.nanoTime() - start;
    System.out.println("Average time to read a line was " + time / runs + " ns.");
    conn.close();
    ss.close();
}

prints

Average time to read a line was 158 ns.

If you want to build a StringBuilder, keeping newlines I would suggets the following approach.

Reader r = new InputStreamReader(conn.getInputStream());
String line;

StringBuilder sb = new StringBuilder();
char[] chars = new char[4*1024];
int len;
while((len = r.read(chars))>=0) {
    sb.append(chars, 0, len);
}

Still prints

Average time to read a line was 159 ns.

In both cases, the speed is limited by the sender not the receiver. By optimising the sender, I got this timing down to 105 ns per line.

CSS center content inside div

The problem is that you assigned a fixed width to your .wrap DIV. The DIV itself is centered (you can see that when you add a border to it) but the DIV is just too wide. In other words the content does not fill the whole width of the DIV.

To solve the problem you have to make sure, that the .wrap DIV is only as wide as it's content.

To achieve that you have to remove the floating in the content elements and set the display property of the block levels elements to inline:

#partners .wrap {
 display: inline;
} 

.wrap { margin: 0 auto; position: relative;}

#partners h2 {
color: #A6A5A5;
font-weight: normal;
margin: 2px 15px 0 0;
display: inline;
}

#partners ul {
display: inline;
}

#partners li {display: inline}

ul { list-style-position: outside; list-style-type: none; }

jQuery click anywhere in the page except on 1 div

try this

 $('html').click(function() {
 //your stuf
 });

 $('#menucontainer').click(function(event){
     event.stopPropagation();
 });

you can also use the outside events

How to center-justify the last line of text in CSS?

Calculate the length of your text line and create a block which is the same size as the line of text. Center the block. If you have two lines you will need two blocks if they are different lengths. You could use a span tag and a br tag if you don't want extra spaces from the blocks. You can also use the pre tag to format inside a block.

And you can do this: style='text-align:center;'

For vertical see: http://www.w3schools.com/cssref/pr_pos_vertical-align.asp

Here is the best way for blocks and web page layouts, go here and learn flex the new standard which started in 2009. http://www.w3.org/TR/2014/WD-css-flexbox-1-20140325/#justify-content-property

Also w3schools has lots of flex examples.

How to add hamburger menu in bootstrap

CSS only (no icon sets) Codepen

_x000D_
_x000D_
.nav-link #navBars {_x000D_
margin-top: -3px;_x000D_
padding: 8px 15px 3px;_x000D_
border: 1px solid rgba(0,0,0,.125);_x000D_
border-radius: .25rem;_x000D_
}_x000D_
_x000D_
.nav-link #navBars input {_x000D_
display: none;_x000D_
}_x000D_
_x000D_
.nav-link #navBars span {_x000D_
position: relative;_x000D_
z-index: 1;_x000D_
display: block;_x000D_
margin-bottom: 6px;_x000D_
width: 24px;_x000D_
height: 2px;_x000D_
background-color: rgba(125, 125, 126, 1);_x000D_
border-radius: .25rem;_x000D_
}
_x000D_
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
<nav class="navbar navbar-expand-lg navbar-light bg-light">_x000D_
   <!-- <a class="navbar-brand" href="#">_x000D_
      <img src="https://getbootstrap.com/docs/4.0/assets/brand/bootstrap-solid.svg" width="30" height="30" class="d-inline-block align-top" alt="">_x000D_
      Bootstrap_x000D_
      </a> -->_x000D_
   <!-- https://stackoverflow.com/questions/26317679 -->_x000D_
   <a class="nav-link" href="#">_x000D_
      <div id="navBars">_x000D_
         <input type="checkbox" /><span></span>_x000D_
         <span></span>_x000D_
         <span></span>_x000D_
      </div>_x000D_
   </a>_x000D_
   <!-- /26317679 -->_x000D_
   <div class="collapse navbar-collapse" id="navbarNav">_x000D_
      <ul class="navbar-nav">_x000D_
         <li class="nav-item active"><a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a></li>_x000D_
         <li class="nav-item"><a class="nav-link" href="#">Features</a></li>_x000D_
         <li class="nav-item"><a class="nav-link" href="#">Pricing</a></li>_x000D_
         <li class="nav-item"><a class="nav-link disabled" href="#">Disabled</a></li>_x000D_
      </ul>_x000D_
   </div>_x000D_
</nav>
_x000D_
_x000D_
_x000D_

Oracle timestamp data type

Quite simply the number is the precision of the timestamp, the fraction of a second held in the column:

SQL> create table t23
  2  (ts0 timestamp(0)
  3   , ts3 timestamp(3)
  4  , ts6 timestamp(6)
  5  )
  6  /

Table created.

SQL> insert into t23 values (systimestamp, systimestamp, systimestamp)
  2  /

1 row created.

SQL> select * from t23
  2  /

TS0
---------------------------------------------------------------------------
TS3
---------------------------------------------------------------------------
TS6
---------------------------------------------------------------------------
24-JAN-12 05.57.12 AM
24-JAN-12 05.57.12.003 AM
24-JAN-12 05.57.12.002648 AM


SQL> 

If we don't specify a precision then the timestamp defaults to six places.

SQL> alter table t23 add ts_def timestamp;

Table altered.

SQL> update t23      
  2  set ts_def = systimestamp
  3  /

1 row updated.

SQL> select * from t23
  2  /

TS0
---------------------------------------------------------------------------
TS3
---------------------------------------------------------------------------
TS6
---------------------------------------------------------------------------
TS_DEF
---------------------------------------------------------------------------
24-JAN-12 05.57.12 AM
24-JAN-12 05.57.12.003 AM
24-JAN-12 05.57.12.002648 AM
24-JAN-12 05.59.27.293305 AM


SQL> 

Note that I'm running on Linux so my TIMESTAMP column actually gives me precision to six places i.e. microseconds. This would also be the case on most (all?) flavours of Unix. On Windows the limit is three places i.e. milliseconds. (Is this still true of the most modern flavours of Windows - citation needed).

As might be expected, the documentation covers this. Find out more.


"when you create timestamp(9) this gives you nanos right"

Only if the OS supports it. As you can see, my OEL appliance does not:

SQL> alter table t23 add ts_nano timestamp(9)
  2  /

Table altered.

SQL> update t23 set ts_nano = systimestamp(9)
  2  /

1 row updated.

SQL> select * from t23
  2  /

TS0
---------------------------------------------------------------------------
TS3
---------------------------------------------------------------------------
TS6
---------------------------------------------------------------------------
TS_DEF
---------------------------------------------------------------------------
TS_NANO
---------------------------------------------------------------------------
24-JAN-12 05.57.12 AM
24-JAN-12 05.57.12.003 AM
24-JAN-12 05.57.12.002648 AM
24-JAN-12 05.59.27.293305 AM
24-JAN-12 08.28.03.990557000 AM


SQL> 

(Those trailing zeroes could be a coincidence but they aren't.)

HTML select form with option to enter custom value

jQuery Solution!

Demo: http://jsfiddle.net/69wP6/2/

Another Demo Below(updated!)

I needed something similar in a case when i had some fixed Options and i wanted one other option to be editable! In this case i made a hidden input that would overlap the select option and would be editable and used jQuery to make it all work seamlessly.

I am sharing the fiddle with all of you!

HTML

<div id="billdesc">
    <select id="test">
      <option class="non" value="option1">Option1</option>
      <option class="non" value="option2">Option2</option>
      <option class="editable" value="other">Other</option>
    </select>
    <input class="editOption" style="display:none;"></input>
</div>

CSS

body{
    background: blue;
}
#billdesc{
    padding-top: 50px;
}
#test{
    width: 100%;
    height: 30px;
}
option {
    height: 30px;
    line-height: 30px;
}

.editOption{
    width: 90%;
    height: 24px;
    position: relative;
    top: -30px

}

jQuery

var initialText = $('.editable').val();
$('.editOption').val(initialText);

$('#test').change(function(){
var selected = $('option:selected', this).attr('class');
var optionText = $('.editable').text();

if(selected == "editable"){
  $('.editOption').show();


  $('.editOption').keyup(function(){
      var editText = $('.editOption').val();
      $('.editable').val(editText);
      $('.editable').html(editText);
  });

}else{
  $('.editOption').hide();
}
});

Edit : Added some simple touches design wise, so people can clearly see where the input ends!

JS Fiddle : http://jsfiddle.net/69wP6/4/

How to redirect to previous page in Ruby On Rails?

request.referer is set by Rack and is set as follows:

def referer
  @env['HTTP_REFERER'] || '/'
end

Just do a redirect_to request.referer and it will always redirect to the true referring page, or the root_path ('/'). This is essential when passing tests that fail in cases of direct-nav to a particular page in which the controller throws a redirect_to :back

Excel Formula: Count cells where value is date

This assumes that the column of potential date values is in column A. You could do something like this in an adjacent column:

Make a nested formula that converts the "date" to its numeric value if it's valid, or an error value to zero if it's not.
Then it converts the valid numeric values to 1's and leaves the zeroes as they are.
Then sum the new column to get the total number of valid dates.

=IF(IFERROR(DATEVALUE(A1),0)>0,1,0)

Get MD5 hash of big files in Python

u can't get it's md5 without read full content. but u can use update function to read the files content block by block.
m.update(a); m.update(b) is equivalent to m.update(a+b)

ORA-28001: The password has expired

C:\>sqlplus /nolog
SQL> connect / as SYSDBA
SQL> select * from dba_profiles;
SQL> alter profile default limit password_life_time unlimited;
SQL> alter user database_name identified by new_password;
SQL> commit;
SQL> exit;

"java.lang.OutOfMemoryError : unable to create new native Thread"

It's likely that your OS does not allow the number of threads you're trying to create, or you're hitting some limit in the JVM. Especially if it's such a round number as 32k, a limit of one kind or another is a very likely culprit.

Are you sure you truly need 32k threads? Most modern languages have some kind of support for pools of reusable threads - I'm sure Java has something in place too (like ExecutorService, as user Jesper mentioned). Perhaps you could request threads from such a pool, instead of manually creating new ones.

How do I fix a NoSuchMethodError?

Most of the times java.lang.NoSuchMethodError is caught be compiler but sometimes it can occur at runtime. If this error occurs at runtime then the only reason could be the change in the class structure that made it incompatible.

Best Explanation: https://www.journaldev.com/14538/java-lang-nosuchmethoderror

ActiveXObject in Firefox or Chrome (not IE!)

No for the moment.

I doubt it will be possible for the future for ActiveX support will be discontinued in near future (as MS stated).

Look here about HTML Object tag, but not anything will be accepted. You should try.

Java web start - Unable to load resource

Try using Janela or github to diagnose the problem.

Merge or combine by rownames

Using merge and renaming your t vector as tt (see the PS of Andrie) :

merge(tt,z,by="row.names",all.x=TRUE)[,-(5:8)]

Now if you would work with dataframes instead of matrices, this would even become a whole lot easier :

z <- as.data.frame(z)
tt <- as.data.frame(tt)
merge(tt,z["symbol"],by="row.names",all.x=TRUE)

Loading scripts after page load?

_x000D_
_x000D_
<script type="text/javascript">_x000D_
$(window).bind("load", function() { _x000D_
_x000D_
// your javascript event_x000D_
_x000D_
)};_x000D_
</script>
_x000D_
_x000D_
_x000D_

How to save picture to iPhone photo library?

You can use this function:

UIImageWriteToSavedPhotosAlbum(UIImage *image, 
                               id completionTarget, 
                               SEL completionSelector, 
                               void *contextInfo);

You only need completionTarget, completionSelector and contextInfo if you want to be notified when the UIImage is done saving, otherwise you can pass in nil.

See the official documentation for UIImageWriteToSavedPhotosAlbum().

Get column index from label in a data frame

The following will do it:

which(colnames(df)=="B")

How to extract duration time from ffmpeg output?

For those who want to perform the same calculations with no additional software in Windows, here is the script for command line script:

set input=video.ts

ffmpeg -i "%input%" 2> output.tmp

rem search "  Duration: HH:MM:SS.mm, start: NNNN.NNNN, bitrate: xxxx kb/s"
for /F "tokens=1,2,3,4,5,6 delims=:., " %%i in (output.tmp) do (
    if "%%i"=="Duration" call :calcLength %%j %%k %%l %%m
)
goto :EOF

:calcLength
set /A s=%3
set /A s=s+%2*60
set /A s=s+%1*60*60
set /A VIDEO_LENGTH_S = s
set /A VIDEO_LENGTH_MS = s*1000 + %4
echo Video duration %1:%2:%3.%4 = %VIDEO_LENGTH_MS%ms = %VIDEO_LENGTH_S%s

Same answer posted here: How to crop last N seconds from a TS video

How to change value of process.env.PORT in node.js?

EDIT: Per @sshow's comment, if you're trying to run your node app on port 80, the below is not the best way to do it. Here's a better answer: How do I run Node.js on port 80?

Original Answer:

If you want to do this to run on port 80 (or want to set the env variable more permanently),

  1. Open up your bash profile vim ~/.bash_profile
  2. Add the environment variable to the file export PORT=80
  3. Open up the sudoers config file sudo visudo
  4. Add the following line to the file exactly as so Defaults env_keep +="PORT"

Now when you run sudo node app.js it should work as desired.

How to create a GUID/UUID in Python

Copied from : https://docs.python.org/2/library/uuid.html (Since the links posted were not active and they keep updating)

>>> import uuid

>>> # make a UUID based on the host ID and current time
>>> uuid.uuid1()
UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')

>>> # make a UUID using an MD5 hash of a namespace UUID and a name
>>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')

>>> # make a random UUID
>>> uuid.uuid4()
UUID('16fd2706-8baf-433b-82eb-8c7fada847da')

>>> # make a UUID using a SHA-1 hash of a namespace UUID and a name
>>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')

>>> # make a UUID from a string of hex digits (braces and hyphens ignored)
>>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}')

>>> # convert a UUID to a string of hex digits in standard form
>>> str(x)
'00010203-0405-0607-0809-0a0b0c0d0e0f'

>>> # get the raw 16 bytes of the UUID
>>> x.bytes
'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f'

>>> # make a UUID from a 16-byte string
>>> uuid.UUID(bytes=x.bytes)
UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')

MySQL Error 1215: Cannot add foreign key constraint

So I tried all the fixes above and no luck. I may be missing the error in my tables -just could not find the cause and I kept getting error 1215. So I used this fix.

In my local environment in phpMyAdmin, I exported data from the table in question. I selected format CSV. While still in phpMyAdmin with the table selected, I selected "More->Options". Here I scrolled down to "Copy table to (database.table). Select "Structure only". Rename the table something, maybe just add the word "copy" next to the current table name. Click "Go" This will create a new table. Export the new table and import it to the new or other server. I am also using phpMyAdmin here also. Once imported change the name of the table back to its original name. Select the new table, select import. For format select CSV. Uncheck "enable foreign key checks". Select "Go". So far all is working good.

I posted my fix on my blog.

How to get the id of the element clicked using jQuery

You can get the id of clicked one by this code

$("span").on("click",function(e){
    console.log(e.target.Id);
});

Use .on() event for future compatibility

Autowiring fails: Not an managed Type

If anyone is strugling with the same problem I solved it by adding @EntityScan in my main class. Just add your model package to the basePackages property.

Fastest way to check if a value exists in a list

Be aware that the in operator tests not only equality (==) but also identity (is), the in logic for lists is roughly equivalent to the following (it's actually written in C and not Python though, at least in CPython):

for element in s:
    if element is target:
        # fast check for identity implies equality
        return True
    if element == target:
        # slower check for actual equality
        return True
return False

In most circumstances this detail is irrelevant, but in some circumstances it might leave a Python novice surprised, for example, numpy.NAN has the unusual property of being not being equal to itself:

>>> import numpy
>>> numpy.NAN == numpy.NAN
False
>>> numpy.NAN is numpy.NAN
True
>>> numpy.NAN in [numpy.NAN]
True

To distinguish between these unusual cases you could use any() like:

>>> lst = [numpy.NAN, 1 , 2]
>>> any(element == numpy.NAN for element in lst)
False
>>> any(element is numpy.NAN for element in lst)
True 

Note the in logic for lists with any() would be:

any(element is target or element == target for element in lst)

However, I should emphasize that this is an edge case, and for the vast majority of cases the in operator is highly optimised and exactly what you want of course (either with a list or with a set).

Overriding a JavaScript function while referencing the original

Not sure if it'll work in all circumstances, but in our case, we were trying to override the describe function in Jest so that we can parse the name and skip the whole describe block if it met some criteria.

Here's what worked for us:

function describe( name, callback ) {
  if ( name.includes( "skip" ) )
    return this.describe.skip( name, callback );
  else
    return this.describe( name, callback );
}

Two things that are critical here:

  1. We don't use an arrow function () =>.

    Arrow functions change the reference to this and we need that to be the file's this.

  2. The use of this.describe and this.describe.skip instead of just describe and describe.skip.

Again, not sure it's of value to anybody but we originally tried to get away with Matthew Crumley's excellent answer but needed to make our method a function and accept params in order to parse them in the conditional.

Sort arrays of primitive types in descending order

In Java 8, a better and more concise approach could be:

double[] arr = {13.6, 7.2, 6.02, 45.8, 21.09, 9.12, 2.53, 100.4};

Double[] boxedarr = Arrays.stream( arr ).boxed().toArray( Double[]::new );
Arrays.sort(boxedarr, Collections.reverseOrder());
System.out.println(Arrays.toString(boxedarr));

This would give the reversed array and is more presentable.

Input: [13.6, 7.2, 6.02, 45.8, 21.09, 9.12, 2.53, 100.4]

Output: [100.4, 45.8, 21.09, 13.6, 9.12, 7.2, 6.02, 2.53]

INSTALL_FAILED_DUPLICATE_PERMISSION... C2D_MESSAGE

In my case I received following error

Installation error: INSTALL_FAILED_DUPLICATE_PERMISSION perm=com.map.permission.MAPS_RECEIVE pkg=com.abc.Firstapp

When I was trying to install the app which have package name com.abc.Secondapp. Here point was that app with package name com.abc.Firstapp was already installed in my application.

I resolved this error by uninstalling the application with package name com.abc.Firstapp and then installing the application with package name com.abc.Secondapp

I hope this will help someone while testing.

Dynamically updating plot in matplotlib

Here is a way which allows to remove points after a certain number of points plotted:

import matplotlib.pyplot as plt
# generate axes object
ax = plt.axes()

# set limits
plt.xlim(0,10) 
plt.ylim(0,10)

for i in range(10):        
     # add something to axes    
     ax.scatter([i], [i]) 
     ax.plot([i], [i+1], 'rx')

     # draw the plot
     plt.draw() 
     plt.pause(0.01) #is necessary for the plot to update for some reason

     # start removing points if you don't want all shown
     if i>2:
         ax.lines[0].remove()
         ax.collections[0].remove()

Difference between "process.stdout.write" and "console.log" in node.js?

Looking at the Node docs apparently console.log is just process.stdout.write with a line-break at the end:

console.log = function (d) {
  process.stdout.write(d + '\n');
};

Source: http://nodejs.org/docs/v0.3.1/api/process.html#process.stdout

How to pass "Null" (a real surname!) to a SOAP web service in ActionScript 3

Tracking it down

At first I thought this was a coercion bug where null was getting coerced to "null" and a test of "null" == null was passing. It's not. I was close, but so very, very wrong. Sorry about that!

I've since done lots of fiddling on wonderfl.net and tracing through the code in mx.rpc.xml.*. At line 1795 of XMLEncoder (in the 3.5 source), in setValue, all of the XMLEncoding boils down to

currentChild.appendChild(xmlSpecialCharsFilter(Object(value)));

which is essentially the same as:

currentChild.appendChild("null");

This code, according to my original fiddle, returns an empty XML element. But why?

Cause

According to commenter Justin Mclean on bug report FLEX-33664, the following is the culprit (see last two tests in my fiddle which verify this):

var thisIsNotNull:XML = <root>null</root>;
if(thisIsNotNull == null){
    // always branches here, as (thisIsNotNull == null) strangely returns true
    // despite the fact that thisIsNotNull is a valid instance of type XML
}

When currentChild.appendChild is passed the string "null", it first converts it to a root XML element with text null, and then tests that element against the null literal. This is a weak equality test, so either the XML containing null is coerced to the null type, or the null type is coerced to a root xml element containing the string "null", and the test passes where it arguably should fail. One fix might be to always use strict equality tests when checking XML (or anything, really) for "nullness."

Solution

The only reasonable workaround I can think of, short of fixing this bug in every damn version of ActionScript, is to test fields for "null" and escape them as CDATA values.

CDATA values are the most appropriate way to mutate an entire text value that would otherwise cause encoding/decoding problems. Hex encoding, for instance, is meant for individual characters. CDATA values are preferred when you're escaping the entire text of an element. The biggest reason for this is that it maintains human readability.

I do not understand how execlp() works in Linux

The limitation of execl is that when executing a shell command or any other script that is not in the current working directory, then we have to pass the full path of the command or the script. Example:

execl("/bin/ls", "ls", "-la", NULL);

The workaround to passing the full path of the executable is to use the function execlp, that searches for the file (1st argument of execlp) in those directories pointed by PATH:

execlp("ls", "ls", "-la", NULL);

What does "static" mean in C?

In C programming, static is a reserved keyword which controls both lifetime as well as visibility. If we declare a variable as static inside a function then it will only visible throughout that function. In this usage, this static variable's lifetime will start when a function call and it will destroy after the execution of that function. you can see the following example:

#include<stdio.h> 
int counterFunction() 
{ 
  static int count = 0; 
  count++; 
  return count; 
} 

int main() 
{ 
  printf("First Counter Output = %d\n", counterFunction()); 
  printf("Second Counter Output = %d ", counterFunction()); 
  return 0; 
}

Above program will give us this Output:

First Counter Output = 1 
Second Counter Output = 1 

Because as soon as we call the function it will initialize the count = 0. And while we execute the counterFunction it will destroy the count variable.

Convert JsonNode into POJO

This should do the trick:

mapper.readValue(fileReader, MyClass.class);

I say should because I'm using that with a String, not a BufferedReader but it should still work.

Here's my code:

String inputString = // I grab my string here
MySessionClass sessionObject;
try {
    ObjectMapper objectMapper = new ObjectMapper();
    sessionObject = objectMapper.readValue(inputString, MySessionClass.class);

Here's the official documentation for that call: http://jackson.codehaus.org/1.7.9/javadoc/org/codehaus/jackson/map/ObjectMapper.html#readValue(java.lang.String, java.lang.Class)

You can also define a custom deserializer when you instantiate the ObjectMapper: http://wiki.fasterxml.com/JacksonHowToCustomDeserializers

Edit: I just remembered something else. If your object coming in has more properties than the POJO has and you just want to ignore the extras you'll want to set this:

    objectMapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);

Or you'll get an error that it can't find the property to set into.

Uncaught TypeError: data.push is not a function

Try This Code $scope.DSRListGrid.data = data; this one for source data

            for (var prop in data[0]) {
                if (data[0].hasOwnProperty(prop)) {
                    $scope.ListColumns.push(
                            {
                                "name": prop,
                                "field": prop,
                                "width": 150,
                                "headerCellClass": 'font-12'
                            }
                    );
                }
            }
            console.log($scope.ListColumns);

Postgres: clear entire database before re-creating / re-populating from bash script

Although the following line is taken from a windows batch script, the command should be quite similar:

psql -U username -h localhost -d postgres -c "DROP DATABASE \"$DATABASE\";"

This command is used to clear the whole database, by actually dropping it. The $DATABASE (in Windows should be %DATABASE%) in the command is a windows style environment variable that evaluates to the database name. You will need to substitute that by your development_db_name.

How to test valid UUID/GUID?

thanks to @usertatha with some modification

function isUUID ( uuid ) {
    let s = "" + uuid;

    s = s.match('^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$');
    if (s === null) {
      return false;
    }
    return true;
}

How do I access the $scope variable in browser's console using AngularJS?

Pick an element in the HTML panel of the developer tools and type this in the console:

angular.element($0).scope()

In WebKit and Firefox, $0 is a reference to the selected DOM node in the elements tab, so by doing this you get the selected DOM node scope printed out in the console.

You can also target the scope by element ID, like so:

angular.element(document.getElementById('yourElementId')).scope()

Addons/Extensions

There are some very useful Chrome extensions that you might want to check out:

  • Batarang. This has been around for a while.

  • ng-inspector. This is the newest one, and as the name suggests, it allows you to inspect your application's scopes.

Playing with jsFiddle

When working with jsfiddle you can open the fiddle in show mode by adding /show at the end of the URL. When running like this you have access to the angular global. You can try it here:

http://jsfiddle.net/jaimem/Yatbt/show

jQuery Lite

If you load jQuery before AngularJS, angular.element can be passed a jQuery selector. So you could inspect the scope of a controller with

angular.element('[ng-controller=ctrl]').scope()

Of a button

 angular.element('button:eq(1)').scope()

... and so on.

You might actually want to use a global function to make it easier:

window.SC = function(selector){
    return angular.element(selector).scope();
};

Now you could do this

SC('button:eq(10)')
SC('button:eq(10)').row   // -> value of scope.row

Check here: http://jsfiddle.net/jaimem/DvRaR/1/show/

CSS On hover show another element

we just can show same label div on hovering like this

<style>
#b {
    display: none;
}

#content:hover~#b{
    display: block;
}

</style>

Is it possible to have a custom facebook like button?

It's possible with a lot of work.

Basically, you have to post likes action via the Open Graph API. Then, you can add a custom design to your like button.

But then, you''ll need to keep track yourself of the likes so a returning user will be able to unlike content he liked previously.

Plus, you'll need to ask user to log into your app and ask them the publish_action permission.

All in all, if you're doing this for an application, it may worth it. For a website where you basically want user to like articles, then this is really to much.

Also, consider that you increase your drop-off rate each time you ask user a permission via a Facebook login.

If you want to see an example, I've recently made an app using the open graph like button, just hover on some photos in the mosaique to see it

Angular2 equivalent of $document.ready()

In order to use jQuery inside Angular only declare the $ as following: declare var $: any;

How to remove jar file from local maven repository which was added with install:install-file?

Delete every things (jar, pom.xml, etc) under your local ~/.m2/repository/phonegap/1.1.0/ directory if you are using a linux OS.

JPA OneToMany and ManyToOne throw: Repeated column in mapping for entity column (should be mapped with insert="false" update="false")

I am not really sure about your question (the meaning of "empty table" etc, or how mappedBy and JoinColumn were not working).

I think you were trying to do a bi-directional relationships.

First, you need to decide which side "owns" the relationship. Hibernate is going to setup the relationship base on that side. For example, assume I make the Post side own the relationship (I am simplifying your example, just to keep things in point), the mapping will look like:

(Wish the syntax is correct. I am writing them just by memory. However the idea should be fine)

public class User{
    @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.ALL, mappedBy="user")
    private List<Post> posts;
}


public class Post {
    @ManyToOne(fetch=FetchType.LAZY)
    @JoinColumn(name="user_id")
    private User user;
}

By doing so, the table for Post will have a column user_id which store the relationship. Hibernate is getting the relationship by the user in Post (Instead of posts in User. You will notice the difference if you have Post's user but missing User's posts).

You have mentioned mappedBy and JoinColumn is not working. However, I believe this is in fact the correct way. Please tell if this approach is not working for you, and give us a bit more info on the problem. I believe the problem is due to something else.


Edit:

Just a bit extra information on the use of mappedBy as it is usually confusing at first. In mappedBy, we put the "property name" in the opposite side of the bidirectional relationship, not table column name.

JavaScript before leaving the page

This what I did to show the confirmation message just when I have unsaved data

window.onbeforeunload = function () {
            if (isDirty) {
                return "There are unsaved data.";
            }
            return undefined;
        }

returning "undefined" will disable the confirmation

Note: returning "null" will not work with IE

Also you can use "undefined" to disable the confirmation

window.onbeforeunload = undefined;

An existing connection was forcibly closed by the remote host - WCF

I have catched the same exception and found a InnerException: SocketException. in the svclog trace.

After looking in the windows event log I saw an error coming from the System.ServiceModel.Activation.TcpWorkerProcess class.

Are you hosting your wcf service in IIS with netTcpBinding and port sharing?

It seems there is a bug in IIS port sharing feature, check the fix:

My solution is to host your WCF service in a Windows Service.

Multiple simultaneous downloads using Wget?

They always say it depends but when it comes to mirroring a website The best exists httrack. It is super fast and easy to work. The only downside is it's so called support forum but you can find your way using official documentation. It has both GUI and CLI interface and it Supports cookies just read the docs This is the best.(Be cureful with this tool you can download the whole web on your harddrive)

httrack -c8 [url]

By default maximum number of simultaneous connections limited to 8 to avoid server overload

How to get json response using system.net.webrequest in c#?

You need to explicitly ask for the content type.

Add this line:

 request.ContentType = "application/json; charset=utf-8";
At the appropriate place

pip install access denied on Windows

I met a similar problem.But the error report is about

[SSL: TLSV1_ALERT_ACCESS_DENIED] tlsv1 alert access denied (_ssl.c:777)

First I tried this https://python-forum.io/Thread-All-pip-install-attempts-are-met-with-SSL-error#pid_28035 ,but seems it couldn't solve my problems,and still repeat the same issue.

And Second if you are working on a business computer,generally it may exist a web content filter(but I can access https://pypi.python.org through browser directly).And solve this issue by adding a proxy server.

For windows,open the Internet properties through IE or Chrome or whatsoever ,then set valid proxy address and port,and this way solve my problems

Or just adding the option pip --proxy [proxy-address]:port install mitmproxy.But you always need to add this option while installing by pypi

The above two solution is alternative for you demand.

How to specify 64 bit integers in c

Use int64_t, that portable C99 code.

int64_t var = 0x0000444400004444LL;

For printing:

#define __STDC_FORMAT_MACROS
#include <inttypes.h>

printf("blabla %" PRIi64 " blabla\n", var);

Converting characters to integers in Java

Character.getNumericValue(c)

The java.lang.Character.getNumericValue(char ch) returns the int value that the specified Unicode character represents. For example, the character '\u216C' (the roman numeral fifty) will return an int with a value of 50.

The letters A-Z in their uppercase ('\u0041' through '\u005A'), lowercase ('\u0061' through '\u007A'), and full width variant ('\uFF21' through '\uFF3A' and '\uFF41' through '\uFF5A') forms have numeric values from 10 through 35. This is independent of the Unicode specification, which does not assign numeric values to these char values.

This method returns the numeric value of the character, as a nonnegative int value;

-2 if the character has a numeric value that is not a nonnegative integer;

-1 if the character has no numeric value.

And here is the link.

How to get the list of all database users

Go for this:

 SELECT name,type_desc FROM sys.sql_logins

When adding a Javascript library, Chrome complains about a missing source map, why?

In my case I had to remove React Dev Tools from Chrome to stop seeing the strange errors during development of React app using a local Express server with a create-react-app client (which uses Webpack). In the interest of community I did a sanity check and quit everything - server/client server/Chrome - and then I opened Chrome and reinstalled React Dev Tools... Started things back up and am seeing this funky address and error again: Error seems to be from React Dev Tools extension in my case

Remove Sub String by using Python

>>> import re
>>> st = " i think mabe 124 + <font color=\"black\"><font face=\"Times New Roman\">but I don't have a big experience it just how I see it in my eyes <font color=\"green\"><font face=\"Arial\">fun stuff"
>>> re.sub("<.*?>","",st)
" i think mabe 124 + but I don't have a big experience it just how I see it in my eyes fun stuff"
>>> 

How can I get a specific number child using CSS?

For modern browsers, use td:nth-child(2) for the second td, and td:nth-child(3) for the third. Remember that these retrieve the second and third td for every row.

If you need compatibility with IE older than version 9, use sibling combinators or JavaScript as suggested by Tim. Also see my answer to this related question for an explanation and illustration of his method.

php.ini & SMTP= - how do you pass username & password

I prefer the PHPMailer tool as it doesn't require PEAR. But either way, you have a misunderstanding: you don't want a PHP-server-wide setting for the SMTP user and password. This should be a per-app (or per-page) setting. If you want to use the same account across different PHP pages, add it to some kind of settings.php file.

Get all parameters from JSP page

<%@ page import = "java.util.Map" %>
Map<String, String[]> parameters = request.getParameterMap();
for(String parameter : parameters.keySet()) {
    if(parameter.toLowerCase().startsWith("question")) {
        String[] values = parameters.get(parameter);
        //your code here
    }
}

How to make a Qt Widget grow with the window size?

In Designer, activate the centralWidget and assign a layout, e.g. horizontal or vertical layout. Then your QFormLayout will automatically resize.

Image of Designer

Always make sure, that all widgets have a layout! Otherwise, automatic resizing will break with that widget!

See also

Controls insist on being too large, and won't resize, in QtDesigner

Up, Down, Left and Right arrow keys do not trigger KeyDown event

The best way to do, I think, is to handle it like the MSDN said on http://msdn.microsoft.com/en-us/library/system.windows.forms.control.previewkeydown.aspx

But handle it, how you really need it. My way (in the example below) is to catch every KeyDown ;-)

    /// <summary>
    /// onPreviewKeyDown
    /// </summary>
    /// <param name="e"></param>
    protected override void OnPreviewKeyDown(PreviewKeyDownEventArgs e)
    {
        e.IsInputKey = true;
    }

    /// <summary>
    /// onKeyDown
    /// </summary>
    /// <param name="e"></param>
    protected override void OnKeyDown(KeyEventArgs e)
    {
        Input.SetFlag(e.KeyCode);
        e.Handled = true;
    }

    /// <summary>
    /// onKeyUp
    /// </summary>
    /// <param name="e"></param>
    protected override void OnKeyUp(KeyEventArgs e)
    {
        Input.RemoveFlag(e.KeyCode);
        e.Handled = true;
    }

SQL Logic Operator Precedence: And and Or

And has precedence over Or, so, even if a <=> a1 Or a2

Where a And b 

is not the same as

Where a1 Or a2 And b,

because that would be Executed as

Where a1 Or (a2 And b)

and what you want, to make them the same, is the following (using parentheses to override rules of precedence):

 Where (a1 Or a2) And b

Here's an example to illustrate:

Declare @x tinyInt = 1
Declare @y tinyInt = 0
Declare @z tinyInt = 0

Select Case When @x=1 OR @y=1 And @z=1 Then 'T' Else 'F' End -- outputs T
Select Case When (@x=1 OR @y=1) And @z=1 Then 'T' Else 'F' End -- outputs F

For those who like to consult references (in alphabetic order):

Why does "return list.sort()" return None, not the list?

list.sort sorts the list in place, i.e. it doesn't return a new list. Just write

newList.sort()
return newList

How to check whether input value is integer or float?

You can use RoundingMode.#UNNECESSARY if you want/accept exception thrown otherwise

new BigDecimal(value).setScale(2, RoundingMode.UNNECESSARY);

If this rounding mode is specified on an operation that yields an inexact result, an ArithmeticException is thrown.

Exception if not integer value:

java.lang.ArithmeticException: Rounding necessary

Prevent linebreak after </div>

The div elements are block elements, so by default they take upp the full available width.

One way is to turn them into inline elements:

.label, .text { display: inline; }

This will have the same effect as using span elements instead of div elements.

Another way is to float the elements:

.label, .text { float: left; }

This will change how the width of the elements is decided, so that thwy will only be as wide as their content. It will also make the elements float beside each other, similar to how images flow beside each other.

You can also consider changing the elements. The div element is intended for document divisions, I usually use a label and a span element for a construct like this:

<label>My Label:</label>
<span>My text</span>

String field value length in mongoDB

I had a similar kind of scenario, but in my case string is not a 1st level attribute. It is inside an object. In here I couldn't find a suitable answer for it. So I thought to share my solution with you all(Hope this will help anyone with a similar kind of problem).

Parent Collection 

{
"Child":
{
"name":"Random Name",
"Age:"09"
}
}

Ex: If we need to get only collections that having child's name's length is higher than 10 characters.

 db.getCollection('Parent').find({$where: function() { 
for (var field in this.Child.name) { 
    if (this.Child.name.length > 10) 
        return true;

}
}})

How to run SUDO command in WinSCP to transfer files from Windows to linux

There is an option in WinSCP that does exactly what you are looking for:

enter image description here

enter image description here

Convert xlsx file to csv using batch

Alternative way of converting to csv. Use libreoffice:

libreoffice --headless --convert-to csv *

Please be aware that this will only convert the first worksheet of your Excel file.

Set database from SINGLE USER mode to MULTI USER

On more than 3 occasions working with SQL Server 2014, I have had a database convert to Single User mode without me changing anything. It must have occurred during database creation somehow. All of the methods above never worked as I always received an error that the database was in single user mode and could not be connected to.

The only thing I got to work was restarting the SQL Server Windows Service. That allowed me to connect to the database and make the necessary changes or to delete the database and start over.

Message 'src refspec master does not match any' when pushing commits in Git

The issue is that you have not configured git to always create new branches on the remote from local ones.

The permanent fix if you always want to just create that new branch on the remote to mirror and track your local branch is:

git config --global push.default current

Now you can git push without anymore errors!

Background color of text in SVG

You could use a filter to generate the background.

_x000D_
_x000D_
<svg width="100%" height="100%">
  <defs>
    <filter x="0" y="0" width="1" height="1" id="solid">
      <feFlood flood-color="yellow" result="bg" />
      <feMerge>
        <feMergeNode in="bg"/>
        <feMergeNode in="SourceGraphic"/>
      </feMerge>
    </filter>
  </defs>
  <text filter="url(#solid)" x="20" y="50" font-size="50">solid background</text>
</svg>
_x000D_
_x000D_
_x000D_

Clearing a string buffer/builder after loop

One option is to use the delete method as follows:

StringBuffer sb = new StringBuffer();
for (int n = 0; n < 10; n++) {
   sb.append("a");

   // This will clear the buffer
   sb.delete(0, sb.length());
}

Another option (bit cleaner) uses setLength(int len):

sb.setLength(0);

See Javadoc for more info:

CROSS JOIN vs INNER JOIN in SQL

CROSS JOIN

AThe CROSS JOIN is meant to generate a Cartesian Product.

A Cartesian Product takes two sets A and B and generates all possible permutations of pair records from two given sets of data.

For instance, assuming you have the following ranks and suits database tables:

The ranks and suits tables

And the ranks has the following rows:

| name  | symbol | rank_value |
|-------|--------|------------|
| Ace   | A      | 14         |
| King  | K      | 13         |
| Queen | Q      | 12         |
| Jack  | J      | 11         |
| Ten   | 10     | 10         |
| Nine  | 9      |  9         |

While the suits table contains the following records:

| name    | symbol |
|---------|--------|
| Club    | ?      |
| Diamond | ?      |
| Heart   | ?      |
| Spade   | ?      |

As CROSS JOIN query like the following one:

SELECT
   r.symbol AS card_rank,
   s.symbol AS card_suit
FROM
   ranks r
CROSS JOIN
   suits s

will generate all possible permutations of ranks and suites pairs:

| card_rank | card_suit |
|-----------|-----------|
| A         | ?         |
| A         | ?         |
| A         | ?         |
| A         | ?         |
| K         | ?         |
| K         | ?         |
| K         | ?         |
| K         | ?         |
| Q         | ?         |
| Q         | ?         |
| Q         | ?         |
| Q         | ?         |
| J         | ?         |
| J         | ?         |
| J         | ?         |
| J         | ?         |
| 10        | ?         |
| 10        | ?         |
| 10        | ?         |
| 10        | ?         |
| 9         | ?         |
| 9         | ?         |
| 9         | ?         |
| 9         | ?         |

INNER JOIN

On the other hand, INNER JOIN does not return the Cartesian Product of the two joining data sets.

Instead, the INNER JOIN takes all elements from the left-side table and matches them against the records on the right-side table so that:

  • if no record is matched on the right-side table, the left-side row is filtered out from the result set
  • for any matching record on the right-side table, the left-side row is repeated as if there was a Cartesian Product between that record and all its associated child records on the right-side table.

For instance, assuming we have a one-to-many table relationship between a parent post and a child post_comment tables that look as follows:

One-to-many table relationship

Now, if the post table has the following records:

| id | title     |
|----|-----------|
| 1  | Java      |
| 2  | Hibernate |
| 3  | JPA       |

and the post_comments table has these rows:

| id | review    | post_id |
|----|-----------|---------|
| 1  | Good      | 1       |
| 2  | Excellent | 1       |
| 3  | Awesome   | 2       |

An INNER JOIN query like the following one:

SELECT
   p.id AS post_id,
   p.title AS post_title,
   pc.review  AS review
FROM post p
INNER JOIN post_comment pc ON pc.post_id = p.id

is going to include all post records along with all their associated post_comments:

| post_id | post_title | review    |
|---------|------------|-----------|
| 1       | Java       | Good      |
| 1       | Java       | Excellent |
| 2       | Hibernate  | Awesome   |

Basically, you can think of the INNER JOIN as a filtered CROSS JOIN where only the matching records are kept in the final result set.

Set Icon Image in Java

Use Default toolkit for this

frame.setIconImage(Toolkit.getDefaultToolkit().getImage("Icon.png"));

Back to previous page with header( "Location: " ); in PHP

You have to save that location somehow.

Say it's a POST form, just put the current location in a hidden field and then use it in the header() Location.

Qt Creator color scheme

In newer versions of Qt Creator (Currently using 4.4.1), you can follow these simple steps:
Tools > Options > Environment > Interface

Here you can change the theme to Flat Dark.

It will change the whole Qt Creator theme, not just the editor window.

enter image description here

CKEditor instance already exists

function loadEditor(id)
{
    var instance = CKEDITOR.instances[id];
    if(instance)
    {
        CKEDITOR.remove(instance);
    }
    CKEDITOR.replace(id);
}

SQL Server Insert if not exists

instead of below Code

BEGIN
   INSERT INTO EmailsRecebidos (De, Assunto, Data)
   VALUES (@_DE, @_ASSUNTO, @_DATA)
   WHERE NOT EXISTS ( SELECT * FROM EmailsRecebidos 
                   WHERE De = @_DE
                   AND Assunto = @_ASSUNTO
                   AND Data = @_DATA);
END

replace with

BEGIN
   IF NOT EXISTS (SELECT * FROM EmailsRecebidos 
                   WHERE De = @_DE
                   AND Assunto = @_ASSUNTO
                   AND Data = @_DATA)
   BEGIN
       INSERT INTO EmailsRecebidos (De, Assunto, Data)
       VALUES (@_DE, @_ASSUNTO, @_DATA)
   END
END

Updated : (thanks to @Marc Durdin for pointing)

Note that under high load, this will still sometimes fail, because a second connection can pass the IF NOT EXISTS test before the first connection executes the INSERT, i.e. a race condition. See stackoverflow.com/a/3791506/1836776 for a good answer on why even wrapping in a transaction doesn't solve this.

Oracle JDBC intermittent Connection Issue

-Djava.security.egd=file:/dev/./urandom should be right! not -Djava.security.egd=file:/dev/../dev/urandom or -Djava.security.egd=file:///dev/urandom

Trigger Change event when the Input value changed programmatically?

If someone is using react, following will be useful:

https://stackoverflow.com/a/62111884/1015678

const valueSetter = Object.getOwnPropertyDescriptor(this.textInputRef, 'value').set;
const prototype = Object.getPrototypeOf(this.textInputRef);
const prototypeValueSetter = Object.getOwnPropertyDescriptor(prototype, 'value').set;
if (valueSetter && valueSetter !== prototypeValueSetter) {
    prototypeValueSetter.call(this.textInputRef, 'new value');
} else {
    valueSetter.call(this.textInputRef, 'new value');
}
this.textInputRef.dispatchEvent(new Event('input', { bubbles: true }));

jquery $(this).id return Undefined

use this actiion

$(document).ready(function () {
var a = this.id;

alert (a);
});

Parsing CSV / tab-delimited txt file with Python

Although there is nothing wrong with the other solutions presented, you could simplify and greatly escalate your solutions by using python's excellent library pandas.

Pandas is a library for handling data in Python, preferred by many Data Scientists.

Pandas has a simplified CSV interface to read and parse files, that can be used to return a list of dictionaries, each containing a single line of the file. The keys will be the column names, and the values will be the ones in each cell.

In your case:

    import pandas

    def create_dictionary(filename):
        my_data = pandas.DataFrame.from_csv(filename, sep='\t', index_col=False)
        # Here you can delete the dataframe columns you don't want!
        del my_data['B']
        del my_data['D']
        # ...
        # Now you transform the DataFrame to a list of dictionaries
        list_of_dicts = [item for item in my_data.T.to_dict().values()]
        return list_of_dicts

# Usage:
x = create_dictionary("myfile.csv")

Sum rows in data.frame or matrix

I came here hoping to find a way to get the sum across all columns in a data table and run into issues implementing the above solutions. A way to add a column with the sum across all columns uses the cbind function:

cbind(data, total = rowSums(data))

This method adds a total column to the data and avoids the alignment issue yielded when trying to sum across ALL columns using the above solutions (see the post below for a discussion of this issue).

Adding a new column to matrix error

What is the shortest function for reading a cookie by name in JavaScript?

To truly remove as much bloat as possible, consider not using a wrapper function at all:

try {
    var myCookie = document.cookie.match('(^|;) *myCookie=([^;]*)')[2]
} catch (_) {
    // handle missing cookie
}

As long as you're familiar with RegEx, that code is reasonably clean and easy to read.

module.exports vs exports in Node.js

Let's create one module with 2 ways:

One way

var aa = {
    a: () => {return 'a'},
    b: () => {return 'b'}
}

module.exports = aa;

Second way

exports.a = () => {return 'a';}
exports.b = () => {return 'b';}

And this is how require() will integrate module.

First way:

function require(){
    module.exports = {};
    var exports = module.exports;

    var aa = {
        a: () => {return 'a'},
        b: () => {return 'b'}
    }
    module.exports = aa;

    return module.exports;
}

Second way

function require(){
    module.exports = {};
    var exports = module.exports;

    exports.a = () => {return 'a';}
    exports.b = () => {return 'b';}

    return module.exports;
}

How do I sort arrays using vbscript?

I actually just had to do something similar but with a 2D array yesterday. I am not that up to speed on vbscript and this process really bogged me down. I found that the articles here were very well written and got me on the road to sorting in vbscript.

How to get index in Handlebars each helper?

Arrays:

{{#each array}}
    {{@index}}: {{this}}
{{/each}}

If you have arrays of objects... you can iterate through the children:

{{#each array}}
    //each this = { key: value, key: value, ...}
    {{#each this}}
        //each key=@key and value=this of child object 
        {{@key}}: {{this}}
        //Or get index number of parent array looping
        {{@../index}}
    {{/each}}
{{/each}}

Objects:

{{#each object}}
    {{@key}}: {{this}}
{{/each}} 

If you have nested objects you can access the key of parent object with {{@../key}}

What is the difference between `new Object()` and object literal notation?

Also, according to some of the O'Really javascript books....(quoted)

Another reason for using literals as opposed to the Object constructor is that there is no scope resolution. Because it’s possible that you have created a local constructor with the same name, the interpreter needs to look up the scope chain from the place you are calling Object() all the way up until it finds the global Object constructor.

Invalid URI: The format of the URI could not be determined

The issue for me was that when i got some domain name, i had:

cloudsearch-..-..-xxx.aws.cloudsearch... [WRONG]

http://cloudsearch-..-..-xxx.aws.cloudsearch... [RIGHT]

hope this does the job for you :)

Vue template or render function not defined yet I am using neither?

The reason you're receiving that error is that you're using the runtime build which doesn't support templates in HTML files as seen here vuejs.org

In essence what happens with vue loaded files is that their templates are compile time converted into render functions where as your base function was trying to compile from your html element.

How to add an extra language input to Android?

I just found Scandinavian Keyboard as a fine solution to this problem. It do also have English and German keyboard, but neither Dutch nor Spanish - but I guess they could be added. And I guess there is other alternatives out there.

Using helpers in model: how do I include helper dependencies?

This gives you just the helper method without the side effects of loading every ActionView::Helpers method into your model:

ActionController::Base.helpers.sanitize(str)

What's the difference between Html.Label, Html.LabelFor and Html.LabelForModel

I think that the usage of @Html.LabelForModel() should be explained in more detail.

The LabelForModel Method returns an HTML label element and the property name of the property that is represented by the model.

You could refer to the following code:

Code in model:

using System.ComponentModel;

[DisplayName("MyModel")]
public class MyModel
{
    [DisplayName("A property")]
    public string Test { get; set; }
}

Code in view:

@Html.LabelForModel()
<div class="form-group">

    @Html.LabelFor(model => model.Test, new { @class = "control-label col-md-2" })

    <div class="col-md-10">
        @Html.EditorFor(model => model.Test)
        @Html.ValidationMessageFor(model => model.Test)
    </div>
</div>

The output screenshot:

enter image description here

Reference to answer on the asp.net forum

Adding an onclick event to a div element

I think You are using //--style="display:none"--// for hiding the div.

Use this code:

<script>
    function klikaj(i) {
        document.getElementById(i).style.display = 'block';
    }
</script>
<div id="thumb0" class="thumbs" onclick="klikaj('rad1')">Click Me..!</div>
<div id="rad1" class="thumbs" style="display:none">Helloooooo</div>

RecyclerView and java.lang.IndexOutOfBoundsException: Inconsistency detected. Invalid view holder adapter positionViewHolder in Samsung devices

This problem is caused by RecyclerView Data modified in different thread

Can confirm threading as one problem and since I ran into the issue and RxJava is becoming increasingly popular: make sure that you are using .observeOn(AndroidSchedulers.mainThread()) whenever you're calling notify[whatever changed]

code example from adapter:

myAuxDataStructure.getChangeObservable().observeOn(AndroidSchedulers.mainThread()).subscribe(new Observer<AuxDataStructure>() {

    [...]

    @Override
    public void onNext(AuxDataStructure o) {
        [notify here]
    }
});

Dynamically fill in form values with jQuery

If you need to hit the database, you need to hit the web server again (for the most part).

What you can do is use AJAX, which makes a request to another script on your site to retrieve data, gets the data, and then updates the input fields you want.

AJAX calls can be made in jquery with the $.ajax() function call, so this will happen

User's browser enters input that fires a trigger that makes an AJAX call

$('input .callAjax').bind('change', function() { 
  $.ajax({ url: 'script/ajax', 
           type: json
           data: $foo,  
           success: function(data) {
             $('input .targetAjax').val(data.newValue);
           });
  );

Now you will need to point that AJAX call at script (sounds like you're working PHP) that will do the query you want and send back data.

You will probably want to use the JSON object call so you can pass back a javascript object, that will be easier to use than return XML etc.

The php function json_encode($phpobj); will be useful.

Java: Identifier expected

Put your code in a method.

Try this:

public class MyClass {
    public static void main(String[] args) {
        UserInput input = new UserInput();
        input.name();
    }
}

Then "run" the class from your IDE

Reference excel worksheet by name?

To expand on Ryan's answer, when you are declaring variables (using Dim) you can cheat a little bit by using the predictive text feature in the VBE, as in the image below. screenshot of predictive text in VBE

If it shows up in that list, then you can assign an object of that type to a variable. So not just a Worksheet, as Ryan pointed out, but also a Chart, Range, Workbook, Series and on and on.

You set that variable equal to the object you want to manipulate and then you can call methods, pass it to functions, etc, just like Ryan pointed out for this example. You might run into a couple snags when it comes to collections vs objects (Chart or Charts, Range or Ranges, etc) but with trial and error you'll get it for sure.

Change application's starting activity

Go to AndroidManifest.xml in the root folder of your project and change the Activity name which you want to execute first.

Example:

<activity android:name=".put your started activity name here"
          android:label="@string/app_name">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

Unable to copy a file from obj\Debug to bin\Debug

Before rebuild the solution, clear the project, stop the IIS and open the "bin" folder property. Uncheck the Read-only Attribute in general tab then rebuild.

How do I do an OR filter in a Django query?

There is Q objects that allow to complex lookups. Example:

from django.db.models import Q

Item.objects.filter(Q(creator=owner) | Q(moderated=False))

How to click a link whose href has a certain substring in Selenium?

I need to click the link who's href has substring "long" in it. How can I do this?

With the beauty of CSS selectors.

your statement would be...

driver.findElement(By.cssSelector("a[href*='long']")).click();

This means, in english,

Find me any 'a' elements, that have the href attribute, and that attribute contains 'long'

You can find a useful article about formulating your own selectors for automation effectively, as well as a list of all the other equality operators. contains, starts with, etc... You can find that at: http://ddavison.io/css/2014/02/18/effective-css-selectors.html

Best way to simulate "group by" from bash?

I feel awk associative array is also handy in this case

$ awk '{count[$1]++}END{for(j in count) print j,count[j]}' ips.txt

A group by post here

What's the best way to build a string of delimited items in Java?

So a couple of things you might do to get the feel that it seems like you're looking for:

1) Extend List class - and add the join method to it. The join method would simply do the work of concatenating and adding the delimiter (which could be a param to the join method)

2) It looks like Java 7 is going to be adding extension methods to java - which allows you just to attach a specific method on to a class: so you could write that join method and add it as an extension method to List or even to Collection.

Solution 1 is probably the only realistic one, now, though since Java 7 isn't out yet :) But it should work just fine.

To use both of these, you'd just add all your items to the List or Collection as usual, and then call the new custom method to 'join' them.

Match exact string

"^" For the begining of the line "$" for the end of it. Eg.:

var re = /^abc$/;

Would match "abc" but not "1abc" or "abc1". You can learn more at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions

How do I compare two files using Eclipse? Is there any option provided by Eclipse?

If one or both of the files you wish to compare isn't in an Eclipse project:

  1. Open the Quick Access search box

    • Linux/Windows: Ctrl+3
    • Mac: ?+3
  2. Type compare and select Compare With Other Resource

  3. Select the files to compare ? OK

You can also create a keyboard shortcut for Compare With Other Resource by going to Window ? Preferences ? General ? Keys

Adding line break in C# Code behind page

Strings are immutable, so using

public string GenerateString()
{
    return
        "abc" +
        "def";
}

will slow you performance - each of those values is a string literal which must be concatenated at runtime - bad news if you reuse the method/property/whatever alot...

Store your string literals in resources is a good idea...

public string GenerateString()
{
    return Resources.MyString;
}

That way it is localisable and the code is tidy (although performance is pretty terrible).

How to iterate using ngFor loop Map containing key as string and values as map iteration

This is because map.keys() returns an iterator. *ngFor can work with iterators, but the map.keys() will be called on every change detection cycle, thus producing a new reference to the array, resulting in the error you see. By the way, this is not always an error as you would traditionally think of it; it may even not break any of your functionality, but suggests that you have a data model which seems to behave in an insane way - changing faster than the change detector checks its value.

If you do no want to convert the map to an array in your component, you may use the pipe suggested in the comments. There is no other workaround, as it seems.

P.S. This error will not be shown in the production mode, as it is more like a very strict warning, rather than an actual error, but still, this is not a good idea to leave it be.

Using isKindOfClass with Swift

I would use:

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {

    super.touchesBegan(touches, withEvent: event)
    let touch : UITouch = touches.anyObject() as UITouch

    if let touchView = touch.view as? UIPickerView
    {

    }
}

Visual Studio 2013 License Product Key

I solved this, without having to completely reinstall Visual Studio 2013.

For those who may come across this in the future, the following steps worked for me:

  1. Run the ISO (or vs_professional.exe).
  2. If you get the error below, you need to update the Windows Registry to trick the installer into thinking you still have the base version. If you don't get this error, skip to step 3 "The product version that you are trying to set up is earlier than the version already installed on this computer."

    • Click the link for 'examine the log file' and look near the bottom of the log, for this line: Detected related bundle ... operation: Downgrade

    • open regedit.exe and do an Edit > Find... for that GUID. In my case it was {6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}. This was found in:

      HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall{6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}

    • Edit the BundleVersion value and change it to a lower version. I changed mine from 12.0.21005.13 to 12.0.21000.13: BundleVersion for Visual Studio lower the version for BundleVersion

    • Exit the registry

  3. Run the ISO (or vs_professional.exe) again. If it has a repair button like the image below, you can skip to step 4.

    Visual Studio Repair button

    • Otherwise you have to let the installer fix the registry. I did this by "installing" at least one feature, even though I think I already had all features (they were not detected). This took about 20 minutes.
  4. Run the ISO (or vs_professional.exe) again. This time repair should be visible.

  5. Click Repair and let it update your installation and apply its embedded license key. This took about 20 minutes.


Now when you run Visual Studio 2013, it should indicate that a license key was applied, under Help > Register Product:

License: Product key applied

Hope this helps somebody in the future!

Reference blog 'story'

making a paragraph in html contain a text from a file

You'll want to use either JavaScript or a server-side language like PHP, ASP...etc

(supposedly can be done with HTML <embed> tag, which makes sense, but I haven't used, since PHP...etc is so simple/common)

Javascript can work: Here's a link to someone doing something similar via javascript on stackoverflow: How do I load the contents of a text file into a javascript variable?

PHP (as example of server-side language) is the easiest way to go though:

<div><p><?php include('myFile.txt'); ?></p></div>

To use this (if you're unfamiliar with PHP), you can:

1) check if you have php on your server

2) change the file extension of your .html file to .php

3) paste the code from my PHP example somewhere in the body of your newly-renamed PHP file

favicon.png vs favicon.ico - why should I use PNG instead of ICO?

Answer replaced (and turned Community Wiki) due to numerous updates and notes from various others in this thread:

  • ICOs and PNGs both allow full alpha channel based transparency
  • ICO allows for backwards compatibility to older browsers (e.g. IE6)
  • PNG probably has broader tooling support for transparency, but you can find tools to create alpha-channel ICOs as well, such as the Dynamic Drive tool and Photoshop plugin mentioned by @mercator.

Feel free to consult the other answers here for more details.

Python - Move and overwrite files and folders

This will go through the source directory, create any directories that do not already exist in destination directory, and move files from source to the destination directory:

import os
import shutil

root_src_dir = 'Src Directory\\'
root_dst_dir = 'Dst Directory\\'

for src_dir, dirs, files in os.walk(root_src_dir):
    dst_dir = src_dir.replace(root_src_dir, root_dst_dir, 1)
    if not os.path.exists(dst_dir):
        os.makedirs(dst_dir)
    for file_ in files:
        src_file = os.path.join(src_dir, file_)
        dst_file = os.path.join(dst_dir, file_)
        if os.path.exists(dst_file):
            # in case of the src and dst are the same file
            if os.path.samefile(src_file, dst_file):
                continue
            os.remove(dst_file)
        shutil.move(src_file, dst_dir)

Any pre-existing files will be removed first (via os.remove) before being replace by the corresponding source file. Any files or directories that already exist in the destination but not in the source will remain untouched.

Single Page Application: advantages and disadvantages

I understand this is an older question, but I would like to add another disadvantage of Single Page Applications:

If you build an API that returns results in a data language (such as XML or JSON) rather than a formatting language (like HTML), you are enabling greater application interoperability, for example, in business-to-business (B2B) applications. Such interoperability has great benefits but does allow people to write software to "mine" (or steal) your data. This particular disadvantage is common to all APIs that use a data language, and not to SPAs in general (indeed, an SPA that asks the server for pre-rendered HTML avoids this, but at the expense of poor model/view separation). This risk exposed by this disadvantage can be mitigated by various means, such as request limiting and connection blocking, etc.

Decimal number regular expression, where digit after decimal is optional

I think this is the best one because it matches all requirements:

^\d+(\\.\d+)?$

Print <div id="printarea"></div> only?

The Best way to Print particular Div or any Element

printDiv("myDiv");

function printDiv(id){
        var printContents = document.getElementById(id).innerHTML;
        var originalContents = document.body.innerHTML;
        document.body.innerHTML = printContents;
        window.print();
        document.body.innerHTML = originalContents;
}

How to sort dates from Oldest to Newest in Excel?

Here's how to sort unsorted dates:

Drag down the column to select the dates you want to sort.

Click Home tab > arrow under Sort & Filter, and then click Sort Oldest to Newest, or Sort Newest to Oldest.

NOTE: If the results aren't what you expected, the column might have dates that are stored as text instead of dates. Convert dates stored as text to dates.

How can I combine hashes in Perl?

Check out perlfaq4: How do I merge two hashes. There is a lot of good information already in the Perl documentation and you can have it right away rather than waiting for someone else to answer it. :)


Before you decide to merge two hashes, you have to decide what to do if both hashes contain keys that are the same and if you want to leave the original hashes as they were.

If you want to preserve the original hashes, copy one hash (%hash1) to a new hash (%new_hash), then add the keys from the other hash (%hash2 to the new hash. Checking that the key already exists in %new_hash gives you a chance to decide what to do with the duplicates:

my %new_hash = %hash1; # make a copy; leave %hash1 alone

foreach my $key2 ( keys %hash2 )
    {
    if( exists $new_hash{$key2} )
        {
        warn "Key [$key2] is in both hashes!";
        # handle the duplicate (perhaps only warning)
        ...
        next;
        }
    else
        {
        $new_hash{$key2} = $hash2{$key2};
        }
    }

If you don't want to create a new hash, you can still use this looping technique; just change the %new_hash to %hash1.

foreach my $key2 ( keys %hash2 )
    {
    if( exists $hash1{$key2} )
        {
        warn "Key [$key2] is in both hashes!";
        # handle the duplicate (perhaps only warning)
        ...
        next;
        }
    else
        {
        $hash1{$key2} = $hash2{$key2};
        }
    }

If you don't care that one hash overwrites keys and values from the other, you could just use a hash slice to add one hash to another. In this case, values from %hash2 replace values from %hash1 when they have keys in common:

@hash1{ keys %hash2 } = values %hash2;

Can I return the 'id' field after a LINQ insert?

Try this:

MyContext Context = new MyContext(); 
Context.YourEntity.Add(obj);
Context.SaveChanges();
int ID = obj._ID;

Is there a job scheduler library for node.js?

node-schedule A cron-like and not-cron-like job scheduler for Node.

Streaming Audio from A URL in Android using MediaPlayer?

I've had the same error as you have and it turned out that there was nothing wrong with the code. The problem was that the webserver was sending the wrong Content-Type header.

Try wireshark or something similar to see what content-type the webserver is sending.

How to select a div element in the code-behind page?

id + runat="server" leads to accessible at the server

How to Flatten a Multidimensional Array?

To flatten w/o recursion (as you have asked for), you can use a stack. Naturally you can put this into a function of it's own like array_flatten. The following is a version that works w/o keys:.

function array_flatten(array $array)
{
    $flat = array(); // initialize return array
    $stack = array_values($array); // initialize stack
    while($stack) // process stack until done
    {
        $value = array_shift($stack);
        if (is_array($value)) // a value to further process
        {
            array_unshift($stack, ...$value);
        }
        else // a value to take
        {
            $flat[] = $value;
        }
    }
    return $flat;
}

Elements are processed in their order. Because subelements will be moved on top of the stack, they will be processed next.

It's possible to take keys into account as well, however, you'll need a different strategy to handle the stack. That's needed because you need to deal with possible duplicate keys in the sub-arrays. A similar answer in a related question: PHP Walk through multidimensional array while preserving keys

I'm not specifically sure, but I I had tested this in the past: The RecurisiveIterator does use recursion, so it depends on what you really need. Should be possible to create a recursive iterator based on stacks as well:

foreach(new FlatRecursiveArrayIterator($array) as $key => $value)
{
    echo "** ($key) $value\n";
}

Demo

I didn't make it so far, to implement the stack based on RecursiveIterator which I think is a nice idea.

Creating an Arraylist of Objects

ArrayList<Matrices> list = new ArrayList<Matrices>();
list.add( new Matrices(1,1,10) );
list.add( new Matrices(1,2,20) );

how to store Image as blob in Sqlite & how to retrieve it?

byte[] byteArray = rs.getBytes("columnname");  

Bitmap bm = BitmapFactory.decodeByteArray(byteArray, 0 ,byteArray.length);

How to get WordPress post featured image URL

You can also get the URL for image attachments as follows. It works fine.

if (has_post_thumbnail()) {
    $image = wp_get_attachment_image_src(get_post_thumbnail_id($post->ID), 'medium'); 
}

How to convert std::string to lower case?

Code Snippet

#include<bits/stdc++.h>
using namespace std;


int main ()
{
    ios::sync_with_stdio(false);

    string str="String Convert\n";

    for(int i=0; i<str.size(); i++)
    {
      str[i] = tolower(str[i]);
    }
    cout<<str<<endl;

    return 0;
}

How to set width of a div in percent in JavaScript?

jQuery way -

$("#id").width('30%');

Git Bash is extremely slow on Windows 7 x64

I saw a decent improvement by setting core.preloadindex to true as recommended here.

How to run Nginx within a Docker container without halting?

To expand on John's answer you can also use the Dockerfile CMD command as following (in case you want it to self start without additional args)

CMD ["nginx", "-g", "daemon off;"]

How do I create a transparent Activity on Android?

All those answers might be confusing, there is a difference between Transparent activity and None UI activity.

Using this:

android:theme="@android:style/Theme.Translucent.NoTitleBar"

Will make the activity transparent but will block the UI.

If you want a None UI activity than use this:

android:theme="@android:style/Theme.NoDisplay"

How to remove "Server name" items from history of SQL Server Management Studio

As of SQL Server 2012 you no longer have to go through the hassle of deleting the bin file (which causes other side effects). You should be able to press the delete key within the MRU list of the Server Name dropdown in the Connect to Server dialog. This is documented in this Connect item and this blog post.

Note that if you have multiple entries for a single server name (e.g. one with Windows and one with SQL Auth), you won't be able to tell which one you're deleting.

Java - What does "\n" mean?

(as per http://java.sun.com/...ex/Pattern.html)

The backslash character ('\') serves to introduce escaped constructs, as defined in the table above, as well as to quote characters that otherwise would be interpreted as unescaped constructs. Thus the expression \\ matches a single backslash and { matches a left brace.

Other examples of usage :

\\ The backslash character<br>
\t The tab character ('\u0009')<br>
\n The newline (line feed) character ('\u000A')<br>
\r The carriage-return character ('\u000D')<br>
\f The form-feed character ('\u000C')<br>
\a The alert (bell) character ('\u0007')<br>
\e The escape character ('\u001B')<br>
\cx The control character corresponding to x <br>

MySQL LIKE IN()?

You can use like this too:

SELECT * FROM fiberbox WHERE fiber IN('140 ', '1938 ', '1940 ')

Comparing two vectors in an if statement

all is one option:

> A <- c("A", "B", "C", "D")
> B <- A
> C <- c("A", "C", "C", "E")

> all(A==B)
[1] TRUE
> all(A==C)
[1] FALSE

But you may have to watch out for recycling:

> D <- c("A","B","A","B")
> E <- c("A","B")
> all(D==E)
[1] TRUE
> all(length(D)==length(E)) && all(D==E)
[1] FALSE

The documentation for length says it currently only outputs an integer of length 1, but that it may change in the future, so that's why I wrapped the length test in all.

Pandas - Get first row value of a given column

To select the ith row, use iloc:

In [31]: df_test.iloc[0]
Out[31]: 
ATime     1.2
X         2.0
Y        15.0
Z         2.0
Btime     1.2
C        12.0
D        25.0
E        12.0
Name: 0, dtype: float64

To select the ith value in the Btime column you could use:

In [30]: df_test['Btime'].iloc[0]
Out[30]: 1.2

There is a difference between df_test['Btime'].iloc[0] (recommended) and df_test.iloc[0]['Btime']:

DataFrames store data in column-based blocks (where each block has a single dtype). If you select by column first, a view can be returned (which is quicker than returning a copy) and the original dtype is preserved. In contrast, if you select by row first, and if the DataFrame has columns of different dtypes, then Pandas copies the data into a new Series of object dtype. So selecting columns is a bit faster than selecting rows. Thus, although df_test.iloc[0]['Btime'] works, df_test['Btime'].iloc[0] is a little bit more efficient.

There is a big difference between the two when it comes to assignment. df_test['Btime'].iloc[0] = x affects df_test, but df_test.iloc[0]['Btime'] may not. See below for an explanation of why. Because a subtle difference in the order of indexing makes a big difference in behavior, it is better to use single indexing assignment:

df.iloc[0, df.columns.get_loc('Btime')] = x

df.iloc[0, df.columns.get_loc('Btime')] = x (recommended):

The recommended way to assign new values to a DataFrame is to avoid chained indexing, and instead use the method shown by andrew,

df.loc[df.index[n], 'Btime'] = x

or

df.iloc[n, df.columns.get_loc('Btime')] = x

The latter method is a bit faster, because df.loc has to convert the row and column labels to positional indices, so there is a little less conversion necessary if you use df.iloc instead.


df['Btime'].iloc[0] = x works, but is not recommended:

Although this works, it is taking advantage of the way DataFrames are currently implemented. There is no guarantee that Pandas has to work this way in the future. In particular, it is taking advantage of the fact that (currently) df['Btime'] always returns a view (not a copy) so df['Btime'].iloc[n] = x can be used to assign a new value at the nth location of the Btime column of df.

Since Pandas makes no explicit guarantees about when indexers return a view versus a copy, assignments that use chained indexing generally always raise a SettingWithCopyWarning even though in this case the assignment succeeds in modifying df:

In [22]: df = pd.DataFrame({'foo':list('ABC')}, index=[0,2,1])
In [24]: df['bar'] = 100
In [25]: df['bar'].iloc[0] = 99
/home/unutbu/data/binky/bin/ipython:1: SettingWithCopyWarning: 
A value is trying to be set on a copy of a slice from a DataFrame

See the caveats in the documentation: http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy
  self._setitem_with_indexer(indexer, value)

In [26]: df
Out[26]: 
  foo  bar
0   A   99  <-- assignment succeeded
2   B  100
1   C  100

df.iloc[0]['Btime'] = x does not work:

In contrast, assignment with df.iloc[0]['bar'] = 123 does not work because df.iloc[0] is returning a copy:

In [66]: df.iloc[0]['bar'] = 123
/home/unutbu/data/binky/bin/ipython:1: SettingWithCopyWarning: 
A value is trying to be set on a copy of a slice from a DataFrame

See the caveats in the documentation: http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy

In [67]: df
Out[67]: 
  foo  bar
0   A   99  <-- assignment failed
2   B  100
1   C  100

Warning: I had previously suggested df_test.ix[i, 'Btime']. But this is not guaranteed to give you the ith value since ix tries to index by label before trying to index by position. So if the DataFrame has an integer index which is not in sorted order starting at 0, then using ix[i] will return the row labeled i rather than the ith row. For example,

In [1]: df = pd.DataFrame({'foo':list('ABC')}, index=[0,2,1])

In [2]: df
Out[2]: 
  foo
0   A
2   B
1   C

In [4]: df.ix[1, 'foo']
Out[4]: 'C'

What is the most efficient way to store a list in the Django models?

A simple way to store a list in Django is to just convert it into a JSON string, and then save that as Text in the model. You can then retrieve the list by converting the (JSON) string back into a python list. Here's how:

The "list" would be stored in your Django model like so:

class MyModel(models.Model):
    myList = models.TextField(null=True) # JSON-serialized (text) version of your list

In your view/controller code:

Storing the list in the database:

import simplejson as json # this would be just 'import json' in Python 2.7 and later
...
...

myModel = MyModel()
listIWantToStore = [1,2,3,4,5,'hello']
myModel.myList = json.dumps(listIWantToStore)
myModel.save()

Retrieving the list from the database:

jsonDec = json.decoder.JSONDecoder()
myPythonList = jsonDec.decode(myModel.myList)

Conceptually, here's what's going on:

>>> myList = [1,2,3,4,5,'hello']
>>> import simplejson as json
>>> myJsonList = json.dumps(myList)
>>> myJsonList
'[1, 2, 3, 4, 5, "hello"]'
>>> myJsonList.__class__
<type 'str'>
>>> jsonDec = json.decoder.JSONDecoder()
>>> myPythonList = jsonDec.decode(myJsonList)
>>> myPythonList
[1, 2, 3, 4, 5, u'hello']
>>> myPythonList.__class__
<type 'list'>

How to select all instances of selected region in Sublime Text

Note: You should not edit the default settings, because they get reset on updates/upgrades. For customization, you should override any setting by using the user bindings.

On Mac:

  • Sublime Text 2 > Preferences > Key Bindings-Default
  • Sublime Text 3 > Preferences > Key Bindings

This opens a document that you can edit the keybindings for Sublime.

If you search "ctrl+super+g" you find this:

{ "keys": ["ctrl+super+g"], "command": "find_all_under" },