Programs & Examples On #Content model

syntaxerror: "unexpected character after line continuation character in python" math

Well, what do you try to do? If you want to use division, use "/" not "\". If it is something else, explain it in a bit more detail, please.

How can I select an element with multiple classes in jQuery?

You can use getElementsByClassName() method for what you want.

var elems = document.getElementsByClassName("a b c");_x000D_
elems[0].style.color = "green";_x000D_
  <li class="a">a</li>_x000D_
  <li class="a b">a, b</li>_x000D_
  <li class="a b c">a, b, c</li>_x000D_

This is the fastest solution also. you can see a benchmark about that here.

What's the difference between TRUNCATE and DELETE in SQL


The DROP command removes a table from the database. All the tables' rows, indexes and privileges will also be removed. No DML triggers will be fired. The operation cannot be rolled back.


TRUNCATE removes all rows from a table. The operation cannot be rolled back and no triggers will be fired. As such, TRUNCATE is faster and doesn't use as much undo space as a DELETE. Table level lock will be added when Truncating.


The DELETE command is used to remove rows from a table. A WHERE clause can be used to only remove some rows. If no WHERE condition is specified, all rows will be removed. After performing a DELETE operation you need to COMMIT or ROLLBACK the transaction to make the change permanent or to undo it. Note that this operation will cause all DELETE triggers on the table to fire. Row level lock will be added when deleting.


In a Dockerfile, How to update PATH environment variable?

You can use Environment Replacement in your Dockerfile as follows:

ENV PATH="/opt/gtk/bin:${PATH}"

how to get domain name from URL

Extracting the Domain name accurately can be quite tricky mainly because the domain extension can contain 2 parts (like or and the subdomain (the prefix) may or may not be there. Listing all domain extensions is not an option because there are hundreds of these. for example lists over 800 domain name extensions.

I therefore wrote a short php function that uses 'parse_url()' and some observations about domain extensions to accurately extract the url components AND the domain name. The function is as follows:

function parse_url_all($url){
    $url = substr($url,0,4)=='http'? $url: 'http://'.$url;
    $d = parse_url($url);
    $tmp = explode('.',$d['host']);
    $n = count($tmp);
    if ($n>=2){
        if ($n==4 || ($n==3 && strlen($tmp[($n-2)])<=3)){
            $d['domain'] = $tmp[($n-3)].".".$tmp[($n-2)].".".$tmp[($n-1)];
            $d['domainX'] = $tmp[($n-3)];
        } else {
            $d['domain'] = $tmp[($n-2)].".".$tmp[($n-1)];
            $d['domainX'] = $tmp[($n-2)];
    return $d;

This simple function will work in almost every case. There are a few exceptions, but these are very rare.

To demonstrate / test this function you can use the following:

$urls = array('', '', '' .....);
echo "<div style='overflow-x:auto;'>";
echo "<table>";
echo "<tr><th>URL</th><th>Host</th><th>Domain</th><th>Domain X</th></tr>";
foreach ($urls as $url) {
    $info = parse_url_all($url);
    echo "<tr><td>".$url."</td><td>".$info['host'].
echo "</table></div>";

The output will be as follows for the URL's listed:

enter image description here

As you can see, the domain name and the domain name without the extension are consistently extracted whatever the URL that is presented to the function.

I hope that this helps.

How to draw circle by canvas in Android?

import android.content.Context;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends Activity 

     public void onCreate(Bundle savedInstanceState)
         setContentView(new MyView(this));

     public class MyView extends View
         Paint paint = null;
         public MyView(Context context) 
              paint = new Paint();

         protected void onDraw(Canvas canvas) 
            int x = getWidth();
            int y = getHeight();
            int radius;
            radius = 100;
            // Use Color.parseColor to define HTML colors
            canvas.drawCircle(x / 2, y / 2, radius, paint);

Edit if you want to draw circle at centre. You could also translate your entire canvas to center then draw circle at center.using

canvas.drawCircle(0,0, radius, paint);

These two link also help

Hash function for a string

Java's String implements hashCode like this:

public int hashCode()

Returns a hash code for this string. The hash code for a String object is computed as

     s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]

using int arithmetic, where s[i] is the ith character of the string, n is the length of the string, and ^ indicates exponentiation. (The hash value of the empty string is zero.) 

So something like this:

int HashTable::hash (string word) {
    int result = 0;
    for(size_t i = 0; i < word.length(); ++i) {
        result += word[i] * pow(31, i);
    return result;

Cannot delete directory with Directory.Delete(path, true)

Before going further, check for the following reasons that are under your control:

  • Is the folder set as a current directory of your process? If yes, change it to something else first.
  • Have you opened a file (or loaded a DLL) from that folder? (and forgot to close/unload it)

Otherwise, check for the following legitimate reasons outside of your control:

  • There are files marked as read-only in that folder.
  • You don't have a deletion permission to some of those files.
  • The file or subfolder is open in Explorer or another app.

If any of the above is the problem, you should understand why it happens before trying to improve your deletion code. Should your app be deleting read-only or inaccessible files? Who marked them that way, and why?

Once you have ruled out the above reasons, there's still a possibility of spurious failures. The deletion will fail if anyone holds a handle to any of the files or folders being deleted, and there are many reasons why someone may be enumerating the folder or reading its files:

  • search indexers
  • anti-viruses
  • backup software

The general approach to deal with spurious failures is to try multiple times, pausing between the attempts. You obviously don't want to keep trying forever, so you should give up after a certain number of attempts and either throw an exception or ignore the error. Like this:

private static void DeleteRecursivelyWithMagicDust(string destinationDir) {
    const int magicDust = 10;
    for (var gnomes = 1; gnomes <= magicDust; gnomes++) {
        try {
            Directory.Delete(destinationDir, true);
        } catch (DirectoryNotFoundException) {
            return;  // good!
        } catch (IOException) { // System.IO.IOException: The directory is not empty
            System.Diagnostics.Debug.WriteLine("Gnomes prevent deletion of {0}! Applying magic dust, attempt #{1}.", destinationDir, gnomes);

            // see for more magic
    // depending on your use case, consider throwing an exception here

In my opinion, a helper like that should be used for all deletions because spurious failures are always possible. However, YOU SHOULD ADAPT THIS CODE TO YOUR USE CASE, not just blindly copy it.

I had spurious failures for an internal data folder generated by my app, located under %LocalAppData%, so my analysis goes like this:

  1. The folder is controlled solely by my application, and the user has no valid reason to go and mark things as read-only or inaccessible inside that folder, so I don't try to handle that case.

  2. There's no valuable user-created stuff in there, so there's no risk of forcefully deleting something by mistake.

  3. Being an internal data folder, I don't expect it to be open in explorer, at least I don't feel the need to specifically handle the case (i.e. I'm fine handling that case via support).

  4. If all attempts fail, I choose to ignore the error. Worst case, the app fails to unpack some newer resources, crashes and prompts the user to contact support, which is acceptable to me as long as it does not happen often. Or, if the app does not crash, it will leave some old data behind, which again is acceptable to me.

  5. I choose to limit retries to 500ms (50 * 10). This is an arbitrary threshold which works in practice; I wanted the threshold to be short enough so that users wouldn't kill the app, thinking that it has stopped responding. On the other hand, half a second is plenty of time for the offender to finish processing my folder. Judging from other SO answers which sometimes find even Sleep(0) to be acceptable, very few users will ever experience more than a single retry.

  6. I retry every 50ms, which is another arbitrary number. I feel that if a file is being processed (indexed, checked) when I try to delete it, 50ms is about the right time to expect the processing to be completed in my case. Also, 50ms is small enough to not result in a noticeable slowdown; again, Sleep(0) seems to be enough in many cases, so we don't want to delay too much.

  7. The code retries on any IO exceptions. I don't normally expect any exceptions accessing %LocalAppData%, so I chose simplicity and accepted the risk of a 500ms delay in case a legitimate exception happens. I also didn't want to figure out a way to detect the exact exception that I want to retry on.

How to get substring from string in c#?

string newString = str.Substring(0,10)

will give you the first 10 characters (from position 0 to position 9).

See here.

Git merge error "commit is not possible because you have unmerged files"

You need to do two things. First add the changes with

git add .
git stash  

git checkout <some branch>

It should solve your issue as it solved to me.

How do you append rows to a table using jQuery?

Maybe this is the answer you are looking for. It finds the last instance of <tr /> and appends the new row after it:

<script type="text/javascript">
    $('a').click(function() {
        $('#myTable tr:last').after('<tr class="child"><td>blahblah<\/td></tr>');

Installing MySQL-python

yum install mysql-devel

It worked for me.

Getting Index of an item in an arraylist; have to loop it

public int getIndex(String itemName)
    for (int i = 0; i < arraylist.size(); i++)
        AuctionItem auction = arraylist.get(i);
        if (itemName.equals(auction.getname()))
            return i;

    return -1;

How to destroy a JavaScript object?

Structure your code so that all your temporary objects are located inside closures instead of global namespace / global object properties and go out of scope when you've done with them. GC will take care of the rest.

Opening database file from within SQLite command-line shell

I wonder why no one was able to get what the question actually asked. It stated What is the command within the SQLite shell tool to specify a database file?

A sqlite db is on my hard disk E:\ABCD\efg\mydb.db. How do I access it with sqlite3 command line interface? .open E:\ABCD\efg\mydb.db does not work. This is what question asked.

I found the best way to do the work is

  • copy-paste all your db files in 1 directory (say E:\ABCD\efg\mydbs)
  • switch to that directory in your command line
  • now open sqlite3 and then .open mydb.db

This way you can do the join operation on different tables belonging to different databases as well.

Sorting arrays in javascript by object key value

Here is yet another one-liner for you:

your_array.sort((a, b) => a.distance === b.distance ? 0 : a.distance > b.distance || -1);

Run function in script from command line (Node JS)

Sometimes you want to run a function via CLI, sometimes you want to require it from another module. Here's how to do both.

// file to run
const runMe = () => {}
if (require.main === module) {
module.exports = runMe Repeater get current index, pointer, or counter

Add a label control to your Repeater's ItemTemplate. Handle OnItemCreated event.


<asp:Repeater ID="rptr" runat="server" OnItemCreated="RepeaterItemCreated">
        <div id="width:50%;height:30px;background:#0f0a0f;">
            <asp:Label ID="lblSr" runat="server" 
               style="width:30%;float:left;text-align:right;text-indent:-2px;" />
               style="width:65%;float:right;text-align:left;text-indent:-2px;" >
            <%# Eval("Item") %>

Code Behind:

    protected void RepeaterItemCreated(object sender, RepeaterItemEventArgs e)
        Label l = e.Item.FindControl("lblSr") as Label;
        if (l != null)
            l.Text = e.Item.ItemIndex + 1+"";

How can I get the image url in a Wordpress theme?

src="<?php bloginfo('template_url'); ?>/image_dir/img.ext"
worked for me for wordpress 3.6 i used it to get header logo using as

<img src="<?php bloginfo('template_url'); ?>/images/logo.jpg">

Unsupported major.minor version 52.0

If your JDK version is right. Another reason that may cause this error is that your Android Studio is in a low version, but your Gradle version is too high. Upgrade your IDE to a newer version may help this.

Stop Excel from automatically converting certain text values to dates

If you put an inverted comma at the start of the field, it will be interpreted as text.

Example: 25/12/2008 becomes '25/12/2008

You are also able to select the field type when importing.

Easy way to password-protect php page

you can specify a password in your php code and only allow users that has the secret url:

in your file:

     if(isset($_GET["pass"] && $_GET["pass"]=="secret"){
           //put your code here
           echo "you're not allowed to access this page";

How do I use NSTimer?

Something like this:

NSTimer *timer;

    timer = [NSTimer scheduledTimerWithTimeInterval: 0.5
                     target: self
                     selector: @selector(handleTimer:)
                     userInfo: nil
                     repeats: YES];

Trigger change event of dropdown

I don't know that much JQuery but I've heard it allows to fire native events with this syntax.


       // Your event handler

    // And now fire change event when the DOM is ready

You must declare the change event handler before calling trigger() or change() otherwise it won't be fired. Thanks for the mention @LenielMacaferi.

More information here.

Setting the default page for ASP.NET (Visual Studio) server configuration

This One Method For Published Solution To Show SpeciFic Page on startup.

Here Is the Route Example to Redirect to Specific Page...

public class RouteConfig
    public static void RegisterRoutes(RouteCollection routes)

            name: "Default",
            url: "{controller}/{action}/{id}",
            defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional },
            namespaces: new[] { "YourSolutionName.Controllers" }

By Default Home Controllers Index method is executed when application is started, Here You Can Define yours.

Note : I am Using Visual Studio 2013 and "YourSolutionName" is to changed to your project Name..

Calculating the SUM of (Quantity*Price) from 2 different tables

I think this is along the lines of what you're looking for. It appears that you want to see the orderid, the subtotal for each item in the order and the total amount for the order.

select o1.orderID, o1.subtotal, sum(o2.UnitPrice * o2.Quantity) as order_total from
    select o.orderID, o.price * o.qty as subtotal
    from product p inner join orderitem o on p.ProductID= o.productID
    where o.orderID = @OrderId
)as o1
inner join orderitem o2 on o1.OrderID = o2.OrderID
group by o1.orderID, o1.subtotal

JavaScript private methods

Using self invoking function and call

JavaScript uses prototypes and does't have classes (or methods for that matter) like Object Oriented languages. A JavaScript developer need to think in JavaScript.

Wikipedia quote:

Unlike many object-oriented languages, there is no distinction between a function definition and a method definition. Rather, the distinction occurs during function calling; when a function is called as a method of an object, the function's local this keyword is bound to that object for that invocation.

Solution using a self invoking function and the call function to call the private "method" :

var MyObject = (function () {
  // Constructor
  function MyObject(foo) {
    this._foo = foo;

  function privateFun(prefix) {
    return prefix + this._foo;
  MyObject.prototype.publicFun = function () {
    return, ">>");
  return MyObject;

var myObject = new MyObject("bar");
myObject.publicFun();      // Returns ">>bar"
myObject.privateFun(">>"); // ReferenceError: private is not defined

The call function allows us to call the private function with the appropriate context (this).

Simpler with Node.js

If you are using Node.js, you don't need the IIFE because you can take advantage of the module loading system:

function MyObject(foo) {
  this._foo = foo;
function privateFun(prefix) {
  return prefix + this._foo;

MyObject.prototype.publicFun = function () {
  return, ">>");
module.exports= MyObject;

Load the file:

var MyObject = require("./MyObject");
var myObject = new MyObject("bar");
myObject.publicFun();      // Returns ">>bar"
myObject.privateFun(">>"); // ReferenceError: private is not defined

(new!) Native private methods in future JavaScript versions

TC39 private methods and getter/setters for JavaScript classes proposal is stage 3. That means any time soon, JavaScript will implement private methods natively!

Note that JavaScript private class fields already exists in modern JavaScript versions.

Here is an example of how it is used:

class MyObject {

  // Private field
  constructor(foo) {
    this.#foo = foo;

  #privateFun(prefix) {
   return prefix + this.#foo;
  publicFun() {
    return this.#privateFun(">>");


You may need a JavaScript transpiler/compiler to run this code on old JavaScript engines.

PS: If you wonder why the # prefix, read this.

(deprecated) ES7 with the Bind Operator

Warning: The bind operator TC39 proposition is near dead

The bind operator :: is an ECMAScript proposal and is implemented in Babel (stage 0).

export default class MyObject {
  constructor (foo) {
    this._foo = foo;

  publicFun () {
    return this::privateFun(">>");

function privateFun (prefix) {
  return prefix + this._foo;

Check if user is using IE

Method 01:
$.browser was deprecated in jQuery version 1.3 and removed in 1.9

if ( $.browser.msie) {
  alert( "Hello! This is IE." );

Method 02:
Using Conditional Comments

<!--[if gte IE 8]>
<p>You're using a recent version of Internet Explorer.</p>

<!--[if lt IE 7]>
<p>Hm. You should upgrade your copy of Internet Explorer.</p>

<![if !IE]>
<p>You're not using Internet Explorer.</p>

Method 03:

 * Returns the version of Internet Explorer or a -1
 * (indicating the use of another browser).
function getInternetExplorerVersion()
    var rv = -1; // Return value assumes failure.

    if (navigator.appName == 'Microsoft Internet Explorer')
        var ua = navigator.userAgent;
        var re  = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
        if (re.exec(ua) != null)
            rv = parseFloat( RegExp.$1 );

    return rv;

function checkVersion()
    var msg = "You're not using Internet Explorer.";
    var ver = getInternetExplorerVersion();

    if ( ver > -1 )
        if ( ver >= 8.0 ) 
            msg = "You're using a recent copy of Internet Explorer."
            msg = "You should upgrade your copy of Internet Explorer.";

    alert( msg );

Method 04:
Use JavaScript/Manual Detection

     Internet Explorer sniffer code to add class to body tag for IE version.
     Can be removed if your using something like Modernizr.
 var ie = (function ()

     var undef,
     v = 3,
         div = document.createElement('div'),
         all = div.getElementsByTagName('i');

     while (
     div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i>< ![endif]-->',

     //append class to body for use with browser support
     if (v > 4)
         $('body').addClass('ie' + v);


Reference Link

How to list all properties of a PowerShell object

If you want to know what properties (and methods) there are:

Get-WmiObject -Class "Win32_computersystem" | Get-Member

How to get the entire document HTML as a string?

I tried the various answers to see what is returned. I'm using the latest version of Chrome.

The suggestion document.documentElement.innerHTML; returned <head> ... </body>

Gaby's suggestion document.getElementsByTagName('html')[0].innerHTML; returned the same.

The suggestion document.documentElement.outerHTML; returned <html><head> ... </body></html> which is everything apart from the 'doctype'.

You can retrieve the doctype object with document.doctype; This returns an object, not a string, so if you need to extract the details as strings for all doctypes up to and including HTML5 it is described here: Get DocType of an HTML as string with Javascript

I only wanted HTML5, so the following was enough for me to create the whole document:

alert('<!DOCTYPE HTML>' + '\n' + document.documentElement.outerHTML);

Difference between mkdir() and mkdirs() in java for

mkdirs() will create the specified directory path in its entirety where mkdir() will only create the bottom most directory, failing if it can't find the parent directory of the directory it is trying to create.

In other words mkdir() is like mkdir and mkdirs() is like mkdir -p.

For example, imagine we have an empty /tmp directory. The following code

new File("/tmp/one/two/three").mkdirs();

would create the following directories:

  • /tmp/one
  • /tmp/one/two
  • /tmp/one/two/three

Where this code:

new File("/tmp/one/two/three").mkdir();

would not create any directories - as it wouldn't find /tmp/one/two - and would return false.

Getting the parent div of element

This might help you.

ParentID = pDoc.offsetParent;

Python assigning multiple variables to same value? list behavior

In python, everything is an object, also "simple" variables types (int, float, etc..).

When you changes a variable value, you actually changes it's pointer, and if you compares between two variables it's compares their pointers. (To be clear, pointer is the address in physical computer memory where a variable is stored).

As a result, when you changes an inner variable value, you changes it's value in the memory and it's affects all the variables that point to this address.

For your example, when you do:

a = b =  5 

This means that a and b points to the same address in memory that contains the value 5, but when you do:

a = 6

It's not affect b because a is now points to another memory location that contains 6 and b still points to the memory address that contains 5.

But, when you do:

a = b = [1,2,3]

a and b, again, points to the same location but the difference is that if you change the one of the list values:

a[0] = 2

It's changes the value of the memory that a is points on, but a is still points to the same address as b, and as a result, b changes as well.

Javascript Uncaught Reference error Function is not defined

If you are using Angular.js then functions imbedded into HTML, such as onclick="function()" or onchange="function()". They will not register. You need to make the change events in the javascript. Such as:

$('#exampleBtn').click(function() {

How to store date/time and timestamps in UTC time zone with JPA and Hibernate

You would think this common problem would be taken care of by Hibernate. But its not! There are a few "hacks" to get it right.

The one I use is to store the Date as a Long in the database. So I am always working with milliseconds after 1/1/70. I then have getters and setters on my Class that return/accept only Dates. So the API remains the same. The down side is that I have longs in the database. SO with SQL I can pretty much only do <,>,= comparisons -- not fancy date operators.

Another approach is to user a custom mapping type as described here:

I think the correct way to deal with this is to use a Calendar instead of a Date though. With the Calendar you can set the TimeZone before persisting.

NOTE: Silly stackoverflow won't let me comment, so here is a response to david a.

If you create this object in Chicago:

new Date(0);

Hibernate persists it as "12/31/1969 18:00:00". Dates should be devoid of timezone, so I'm not sure why the adjustment would be made.

'pip install' fails for every package ("Could not find a version that satisfies the requirement")

Upgrade pip as follows:

curl | python

Note: You may need to use sudo python above if not in a virtual environment.

What's happening: sites are stopping support for TLS versions 1.0 and 1.1. This means that Mac OS X version 10.12 (Sierra) or older will not be able to use pip unless they upgrade pip as above.

(Note that upgrading pip via pip install --upgrade pip will also not upgrade it correctly. It is a chicken-and-egg issue)

This thread explains it (thanks to this Twitter post):

Mac users who use pip and PyPI:

If you are running macOS/OS X version 10.12 or older, then you ought to upgrade to the latest pip (9.0.3) to connect to the Python Package Index securely:

curl | python

and we recommend you do that by April 8th.

Pip 9.0.3 supports TLSv1.2 when running under system Python on macOS < 10.13. Official release notes:

Also, the Python status page:

Completed - The rolling brownouts are finished, and TLSv1.0 and TLSv1.1 have been disabled. Apr 11, 15:37 UTC

Update - The rolling brownouts have been upgraded to a blackout, TLSv1.0 and TLSv1.1 will be rejected with a HTTP 403 at all times. Apr 8, 15:49 UTC

Lastly, to avoid other install errors, make sure you also upgrade setuptools after doing the above:

pip install --upgrade setuptools

What exactly is RESTful programming?

This is amazingly long "discussion" and yet quite confusing to say the least.


1) There is no such a thing as restful programing, without a big joint and lots of beer :)

2) Representational State Transfer (REST) is an architectural style specified in the dissertation of Roy Fielding. It has a number of constraints. If your Service/Client respect those then it is RESTful. This is it.

You can summarize(significantly) the constraints to :

  • stateless communication
  • respect HTTP specs (if HTTP is used)
  • clearly communicates the content formats transmitted
  • use hypermedia as the engine of application state

There is another very good post which explains things nicely.

A lot of answers copy/pasted valid information mixing it and adding some confusion. People talk here about levels, about RESTFul URIs(there is not such a thing!), apply HTTP methods GET,POST,PUT ... REST is not about that or not only about that.

For example links - it is nice to have a beautifully looking API but at the end the client/server does not really care of the links you get/send it is the content that matters.

In the end any RESTful client should be able to consume to any RESTful service as long as the content format is known.

How can I get jQuery to perform a synchronous, rather than asynchronous, Ajax request?

I used the answer given by Carcione and modified it to use JSON.

 function getUrlJsonSync(url){

    var jqxhr = $.ajax({
        type: "GET",
        url: url,
        dataType: 'json',
        cache: false,
        async: false

    // 'async' has to be 'false' for this to work
    var response = {valid: jqxhr.statusText,  data: jqxhr.responseJSON};

    return response;

function testGetUrlJsonSync()
    var reply = getUrlJsonSync("myurl");

    if (reply.valid == 'OK')
        alert('not valid');

I added the dataType of 'JSON' and changed the .responseText to responseJSON.

I also retrieved the status using the statusText property of the returned object. Note, that this is the status of the Ajax response, not whether the JSON is valid.

The back-end has to return the response in correct (well-formed) JSON, otherwise the returned object will be undefined.

There are two aspects to consider when answering the original question. One is telling Ajax to perform synchronously (by setting async: false) and the other is returning the response via the calling function's return statement, rather than into a callback function.

I also tried it with POST and it worked.

I changed the GET to POST and added data: postdata

function postUrlJsonSync(url, postdata){

    var jqxhr = $.ajax({
        type: "POST",
        url: url,
        data: postdata,
        dataType: 'json',
        cache: false,
        async: false

    // 'async' has to be 'false' for this to work
    var response = {valid: jqxhr.statusText,  data: jqxhr.responseJSON};

    return response;

Note that the above code only works in the case where async is false. If you were to set async: true the returned object jqxhr would not be valid at the time the AJAX call returns, only later when the asynchronous call has finished, but that is much too late to set the response variable.

How to get keyboard input in pygame?

Just fyi, if you're trying to ensure the ship doesn't go off of the screen with

if location==-1:

you can probably better use

location -= 1
location = max(0, location)

This way if it skips -1 your program doesn't break

Moving average or running mean

There is a comment by mab buried in one of the answers above which has this method. bottleneck has move_mean which is a simple moving average:

import numpy as np
import bottleneck as bn

a = np.arange(10) + np.random.random(10)

mva = bn.move_mean(a, window=2, min_count=1)

min_count is a handy parameter that will basically take the moving average up to that point in your array. If you don't set min_count, it will equal window, and everything up to window points will be nan.

What is the Record type in typescript?

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

For example, say I have a Union like this:

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

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

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

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

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

You get very strong type safety:

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

Real-world React example.

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

I had a union like this:

type Statuses = "failed" | "complete";

I used this to create an object like this:

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

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

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

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

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

Delete all Duplicate Rows except for One in MySQL?

If you want to keep the row with the lowest id value:

                    FROM (SELECT MIN(
                            FROM NAMES n
                        GROUP BY x)

If you want the id value that is the highest:

                    FROM (SELECT MAX(
                            FROM NAMES n
                        GROUP BY x)

The subquery in a subquery is necessary for MySQL, or you'll get a 1093 error.

How can I check if a var is a string in JavaScript?

My personal approach, which seems to work for all cases, is testing for the presence of members that will all only be present for strings.

function isString(x) {
    return (typeof x == 'string' || typeof x == 'object' && x.toUpperCase && x.substr && x.charAt && x.trim && x.replace ? true : false);


I'd like to know if this method has flaws, but it has served me well for years.

Deep copy an array in Angular 2 + TypeScript

A clean way of deep copying objects having nested objects inside is by using lodash's cloneDeep method.

For Angular, you can do it like this:

Install lodash with yarn add lodash or npm install lodash.

In your component, import cloneDeep and use it:

import * as cloneDeep from 'lodash/cloneDeep';
clonedObject = cloneDeep(originalObject);

It's only 18kb added to your build, well worth for the benefits.

I've also written an article here, if you need more insight on why using lodash's cloneDeep.

Taskkill /f doesn't kill a process

In my case none of the solutions here worked. I eventually found that the program in question was frozen trying to poll USB audio interfaces. So I unplugged a USB DAC I had connected, and to my surprise the application quit instantly. Francis' answer mentions that it could be a result of "unprocessed I/O requests that hasn't been handled properly (by a device driver your program has possibly accessed)", which might explain why this fixed it.

I suppose it really depends on what the program was doing when it froze, but if none of the other solutions are working, try disconnecting all USB devices to see if one of them could be the cause.

Xcode 10 Error: Multiple commands produce

If you are getting this from the Ditto command creating multiple instances of the same name (NOT the 'copy files' build phase), you may have to change the Product Module Name.

  1. Click on your Target(s) Xcode is complaining about
  2. Click on Build Settings
  3. Search for Product Module Name
  4. Change the name to something unique

We have a watch target and a few notification targets in our app, so I just put things like Extension on the end of the module name.

I found this solution originally here:

alternatives to REPLACE on a text or ntext datatype

Assuming SQL Server 2000, the following StackOverflow question should address your problem.

If using SQL Server 2005/2008, you can use the following code (taken from here):

select cast(replace(cast(myntext as nvarchar(max)),'find','replace') as ntext)
from myntexttable

How to avoid Sql Query Timeout

Your query is probably fine. "The semaphore timeout period has expired" is a Network error, not a SQL Server timeout.

There is apparently some sort of network problem between you and the SQL Server.

edit: However, apparently the query runs for 15-20 min before giving the network error. That is a very long time, so perhaps the network error could be related to the long execution time. Optimization of the underlying View might help.

If [MyTable] in your example is a View, can you post the View Definition so that we can have a go at optimizing it?

Click to call html

tl;dr What to do in modern (2018) times? Assume tel: is supported, use it and forget about anything else.

The tel: URI scheme RFC5431 (as well as sms: but also feed:, maps:, youtube: and others) is handled by protocol handlers (as mailto: and http: are).

They're unrelated to HTML5 specification (it has been out there from 90s and documented first time back in 2k with RFC2806) then you can't check for their support using tools as modernizr. A protocol handler may be installed by an application (for example Skype installs a callto: protocol handler with same meaning and behaviour of tel: but it's not a standard), natively supported by browser or installed (with some limitations) by website itself.

What HTML5 added is support for installing custom web based protocol handlers (with registerProtocolHandler() and related functions) simplifying also the check for their support through isProtocolHandlerRegistered() function.

There is some easy ways to determine if there is an handler or not:" How to detect browser's protocol handlers?).

In general what I suggest is:

  1. If you're running on a mobile device then you can safely assume tel: is supported (yes, it's not true for very old devices but IMO you can ignore them).
  2. If JS isn't active then do nothing.
  3. If you're running on desktop browsers then you can use one of the techniques in the linked post to determine if it's supported.
  4. If tel: isn't supported then change links to use callto: and repeat check desctibed in 3.
  5. If tel: and callto: aren't supported (or - in a desktop browser - you can't detect their support) then simply remove that link replacing URL in href with javascript:void(0) and (if number isn't repeated in text span) putting, telephone number in title. Here HTML5 microdata won't help users (just search engines). Note that newer versions of Skype handle both callto: and tel:.

Please note that (at least on latest Windows versions) there is always a - fake - registered protocol handler called App Picker (that annoying window that let you choose with which application you want to open an unknown file). This may vanish your tests so if you don't want to handle Windows environment as a special case you can simplify this process as:

  1. If you're running on a mobile device then assume tel: is supported.
  2. If you're running on desktop then replace tel: with callto:. then drop tel: or leave it as is (assuming there are good chances Skype is installed).

Python Unicode Encode Error

You can use something of the form


which will convert a UTF-8 encoded bytestring into a Python Unicode string. But the exact procedure to use depends on exactly how you load and parse the XML file, e.g. if you don't ever access the XML string directly, you might have to use a decoder object from the codecs module.

How to get pixel data from a UIImage (Cocoa Touch) or CGImage (Core Graphics)?

Apple's Technical Q&A QA1509 shows the following simple approach:

CFDataRef CopyImagePixels(CGImageRef inImage)
    return CGDataProviderCopyData(CGImageGetDataProvider(inImage));

Use CFDataGetBytePtr to get to the actual bytes (and various CGImageGet* methods to understand how to interpret them).

create a white rgba / CSS3

The code you have is a white with low opacity.

If something white with a low opacity is above something black, you end up with a lighter shade of gray. Above red? Lighter red, etc. That is how opacity works.

Here is a simple demo.

If you want it to look 'more white', make it less opaque:

background:rgba(255,255,255, 0.9);


I have 2 dates in PHP, how can I run a foreach loop to go through all of those days?

$date = new DateTime($_POST['date']);
$endDate = date_add(new DateTime($_POST['date']),date_interval_create_from_date_string("7 days"));

while ($date <= $endDate) {
    print date_format($date,'d-m-Y')." AND END DATE IS : ".date_format($endDate,'d-m-Y')."\n";
    date_add($date,date_interval_create_from_date_string("1 days"));

You can iterate like this also, The $_POST['date'] can be dent from your app or website Instead of $_POST['date'] you can also place your string here "21-12-2019". Both will work.

How to return only 1 row if multiple duplicate rows and still return rows that are not duplicates?

Try this if you want to display one of duplicate rows based on RequestID and CreatedDate and show the latest HistoryStatus.

with t as (select row_number()over(partition by RequestID,CreatedDate order by RequestID) as rnum,* from tbltmp)
Select RequestID,CreatedDate,HistoryStatus from t a where  rnum in (SELECT Max(rnum) FROM t GROUP BY RequestID,CreatedDate having t.RequestID=a.RequestID)

or if you want to select one of duplicate rows considering CreatedDate only and show the latest HistoryStatus then try the query below.

with t as (select row_number()over(partition by CreatedDate order by RequestID) as rnum,* from tbltmp)
Select RequestID,CreatedDate,HistoryStatus from t  where  rnum = (SELECT Max(rnum) FROM t)

Or if you want to select one of duplicate rows considering Request ID only and show the latest HistoryStatus then use the query below

with t as (select row_number()over(partition by RequestID order by RequestID) as rnum,* from tbltmp)
Select RequestID,CreatedDate,HistoryStatus from t a where  rnum in (SELECT Max(rnum) FROM t GROUP BY RequestID,CreatedDate having t.RequestID=a.RequestID)

All the above queries I have written in sql server 2005.

Get a json via Http Request in NodeJS

Just setting json option to true, the body will contain the parsed json:

  url: 'http://...',
  json: true
}, function(error, response, body) {

Looping through a Scripting.Dictionary using index/item number

Adding to assylias's answer - assylias shows us D.ITEMS is a method that returns an array. Knowing that, we don't need the variant array a(i) [See caveat below]. We just need to use the proper array syntax.

For i = 0 To d.Count - 1
    s = d.Items()(i)
    Debug.Print s
Next i()

KEYS works the same way

For i = 0 To d.Count - 1
    Debug.Print d.Keys()(i), d.Items()(i)
Next i

This syntax is also useful for the SPLIT function which may help make this clearer. SPLIT also returns an array with lower bounds at 0. Thus, the following prints "C".

Debug.Print Split("A,B,C,D", ",")(2)

SPLIT is a function. Its parameters are in the first set of parentheses. Methods and Functions always use the first set of parentheses for parameters, even if no parameters are needed. In the example SPLIT returns the array {"A","B","C","D"}. Since it returns an array we can use a second set of parentheses to identify an element within the returned array just as we would any array.

Caveat: This shorter syntax may not be as efficient as using the variant array a() when iterating through the entire dictionary since the shorter syntax invokes the dictionary's Items method with each iteration. The shorter syntax is best for plucking a single item by number from a dictionary.

Can you center a Button in RelativeLayout?

you must have aligned it to left or right of parent view

don't use any of these when using android:centerInParent="true" codes:-





Find substring in the string in TWIG

Just searched for the docs, and found this:

Containment Operator: The in operator performs containment test. It returns true if the left operand is contained in the right:

{# returns true #}

{{ 1 in [1, 2, 3] }}

{{ 'cd' in 'abcde' }}

Converting SVG to PNG using C#

You can call the command-line version of inkscape to do this:

Also there is a C# SVG rendering engine, primarily designed to allow SVG files to be used on the web on codeplex that might suit your needs if that is your problem:

Original Project

Fork with fixes and more activity: (added 7/2013)

Python: How to pip install opencv2 with specific version 2.4.9?

There's another easy way, you can type in terminal

sudo apt-get install python-opencv

Install OpenCV-Python in Ubuntu

After installing it, you can use opencv version 2.4 in both c++ and python.

But I recommend you should use opencv 3.2.0 and opencv-contrib, it gives more features

Hope this can help!

How to put the legend out of the plot

Not exactly what you asked for, but I found it's an alternative for the same problem. Make the legend semi-transparant, like so: matplotlib plot with semi transparent legend and semitransparent text box

Do this with:

fig = pylab.figure()
ax = fig.add_subplot(111)
# Make the legend transparent:
# Make a transparent text box
ax.text(0.02,0.02,yourstring, verticalalignment='bottom',
                     bbox={'facecolor':'white', 'alpha':0.6, 'pad':10},

Use a JSON array with objects with javascript

This is your dataArray:


Then parseJson can be used:

$(jQuery.parseJSON(JSON.stringify(dataArray))).each(function() {  
    var ID =;
    var TITLE = this.Title;

Index of duplicates items in a python list

In a single line with pandas 1.2.2 and numpy:

 import numpy as np
 import pandas as pd
 idx = np.where(pd.DataFrame(List).duplicated(keep=False))

The argument keep=False will mark every duplicate as True and np.where() will return an array with the indices where the element in the array was True.

C#: easiest way to populate a ListBox from a List

This also could be easiest way to add items in ListBox.

for (int i = 0; i < MyList.Count; i++)

Further improvisation of this code can add items at runtime.

SQL Logic Operator Precedence: And and Or

  1. Arithmetic operators
  2. Concatenation operator
  3. Comparison conditions
  6. Not equal to
  7. NOT logical condition
  8. AND logical condition
  9. OR logical condition

You can use parentheses to override rules of precedence.

Find a value in an array of objects in Javascript

Are you looking for generic Search(Filter) across the item in the object list without specifying the item key


var productList = [{category: 'Sporting Goods', price: '$49.99', stocked: true, name: 'Football'}, {category: 'Sporting Goods', price: '$9.99', stocked: true, name: 'Baseball'}, {category: 'Sporting Goods', price: '$29.99', stocked: false, name: 'Basketball'}, {category: 'Electronics', price: '$99.99', stocked: true, name: 'iPod Touch'}, {category: 'Electronics', price: '$399.99', stocked: false, name: 'iPhone 5'}, {category: 'Electronics', price: '$199.99', stocked: true, name: 'Nexus 7'}]
function customFilter(objList, text){
if(undefined === text || text === '' ) return objList;
return objList.filter(product => {
    let flag;
    for(let prop in product){
        flag = false;
        flag = product[prop].toString().indexOf(text) > -1;
return flag;


customFilter(productList, '$9');

enter image description here

select data up to a space?

If the first column is always the same size (including the spaces), then you can just take those characters (via LEFT) and clean up the spaces (with RTRIM):

SELECT RTRIM(LEFT(YourColumn, YourColumnSize))

Alternatively, you can extract the second (or third, etc.) column (using SUBSTRING):

SELECT RTRIM(SUBSTRING(YourColumn, PreviousColumnSizes, YourColumnSize))

One benefit of this approach (especially if YourColumn is the result of a computation) is that YourColumn is only specified once.

How to send HTTP request in java?

I know others will recommend Apache's http-client, but it adds complexity (i.e., more things that can go wrong) that is rarely warranted. For a simple task, will do.

URL url = new URL("");
InputStream is = url.openStream();
try {
  /* Now read the retrieved document from the stream. */
} finally {

How to use document.getElementByName and getElementByTag?

  1. The getElementsByName() method accesses all elements with the specified name. this method returns collection of elements that is an array.
  2. The getElementsByTagName() method accesses all elements with the specified tagname. this method returns collection of elements that is an array.
  3. Accesses the first element with the specified id. this method returns only a single element.


<script type="text/javascript">
    function getElements() {
        var x=document.getElementById("y");
    <input name="x" id="y" type="text" size="20" /><br />

This will return a single HTML element and display the value attribute of it.

<script type="text/javascript">
    function getElements() {
        var x=document.getElementsByName("x");
    <input name="x" id="y" type="text" size="20" /><br />
    <input name="x" id="y" type="text" size="20" /><br />

this will return an array of HTML elements and number of elements that match the name attribute.

Extracted from w3schools.

What is the HTML unicode character for a "tall" right chevron?

I use ? (0x25B8) for the right arrow, often to show a collapsed list; and I pair it with ? (0x25BE) to show the list opened up. Both are unobtrusive.

Simple Pivot Table to Count Unique Values

I usually sort the data by the field I need to do the distinct count of then use IF(A2=A1,0,1); you get then get a 1 in the top row of each group of IDs. Simple and doesn't take any time to calculate on large datasets.

Change selected value of kendo ui dropdownlist

You have to use Kendo UI DropDownList select method (documentation in here).

Basically you should:

// get a reference to the dropdown list
var dropdownlist = $("#Instrument").data("kendoDropDownList");

If you know the index you can use:

// selects by index;

If not, use:

// selects item if its text is equal to "test" using predicate function {
    return dataItem.symbol === "test";

JSFiddle example here

Fastest way to check if a string is JSON in PHP?

This will do it:

function isJson($string) {
    $decoded = json_decode($string); // decode our JSON string
    if ( !is_object($decoded) && !is_array($decoded) ) {
        If our string doesn't produce an object or array
        it's invalid, so we should return false
        return false;
    If the following line resolves to true, then there was
    no error and our JSON is valid, so we return true.
    Otherwise it isn't, so we return false.
    return (json_last_error() == JSON_ERROR_NONE);

if ( isJson($someJsonString) ) {
    echo "valid JSON";
} else {
    echo "not valid JSON";

As shown in other answers, json_last_error() returns any error from our last json_decode(). However there are some edge use cases where this function alone is not comprehensive enough. For example, if you json_decode() an integer (eg: 123), or a string of numbers with no spaces or other characters (eg: "123"), the json_last_error() function will not catch an error.

To combat this, I've added an extra step that ensures the result of our json_decode() is either an object or an array. If it's not, then we return false.

To see this in action, check these two examples:

Can't create a docker image for COPY failed: stat /var/lib/docker/tmp/docker-builder error

When using the Docker compose files, publish, publishes to obj/Docker/Publish. When I copied my files there and pointed my Dockerfile to this directory (as generated), it works…

Python: Total sum of a list of numbers with the for loop

l = [1,2,3,4,5]
sum = 0
for x in l:
    sum = sum + x

And you can change l for any list you want.

What is the difference between _tmain() and main() in C++?

With a little effort of templatizing this, it wold work with any list of objects.

#include <iostream>
#include <string>
#include <vector>

char non_repeating_char(std::string str){
    while(str.size() >= 2){
        std::vector<size_t> rmlist; 
        for(size_t  i = 1;  i < str.size(); i++){        
            if(str[0] == str[i]) {

            size_t s = 0;  // Need for terator position adjustment   
            str.erase(str.begin() + 0);
            for (size_t j : rmlist){   
                str.erase(str.begin() + (j-s));                
        return str[0];
    if(str.size() == 1) return str[0];
    else return -1;

int main(int argc, char ** args)
    std::string test = "FabaccdbefafFG";
    test = args[1];
    char non_repeating = non_repeating_char(test);
    Std::cout << non_repeating << '\n';

How to edit CSS style of a div using C# in .NET

Add runat to the element in the markup

<div id="formSpinner" runat="server">
    <img src="images/spinner.gif">

Then you can get to the control's class attributes by using formSpinner.Attributes("class") It will only be a string, but you should be able to edit it.

json.decoder.JSONDecodeError: Extra data: line 2 column 1 (char 190)

You have two records in your json file, and json.loads() is not able to decode more than one. You need to do it record by record.

See Python json.loads shows ValueError: Extra data

OR you need to reformat your json to contain an array:

    "foo" : [
       {"name": "XYZ", "address": "54.7168,94.0215", "country_of_residence": "PQR", "countries": "LMN;PQRST", "date": "28-AUG-2008", "type": null},
       {"name": "OLMS", "address": null, "country_of_residence": null, "countries": "Not identified;No", "date": "23-FEB-2017", "type": null}

would be acceptable again. But there cannot be several top level objects.

How do I activate a virtualenv inside PyCharm's terminal?

I just added a script named pycharmactivate to my home directory. Set value of PyCharm (4.0.1) File > Settings > Tools > Terminal > Shell path to /bin/bash --rcfile ~/pycharmactivate. Maybe not the best solution incase you have different project and virtualenv directories/names but it works for me. This script contains the following 3 lines and assumes your virtualenv has the same name as your project dir.

source ~/.bashrc
source ~/.virtualenvs/$projectdir/bin/activate

Java HTML Parsing

HTMLUnit might be of help. It does a lot more stuff too.

Run reg command in cmd (bat file)?

You could also just create a Group Policy Preference and have it create the reg key for you. (no scripting involved)

How to make sql-mode="NO_ENGINE_SUBSTITUTION" permanent in MySQL my.cnf

It should be:


instead of


then restart mysqld service.

Where can I find documentation on formatting a date in JavaScript?

If you don't need all the features that a library like Moment.js provides, then you can use my port of strftime. It's lightweight (1.35 KB vs. 57.9 KB minified compared to Moment.js 2.15.0) and provides most of the functionality of strftime().

/* Port of strftime(). Compatibility notes:
 * %c - formatted string is slightly different
 * %D - not implemented (use "%m/%d/%y" or "%d/%m/%y")
 * %e - space is not added
 * %E - not implemented
 * %h - not implemented (use "%b")
 * %k - space is not added
 * %n - not implemented (use "\n")
 * %O - not implemented
 * %r - not implemented (use "%I:%M:%S %p")
 * %R - not implemented (use "%H:%M")
 * %t - not implemented (use "\t")
 * %T - not implemented (use "%H:%M:%S")
 * %U - not implemented
 * %W - not implemented
 * %+ - not implemented
 * %% - not implemented (use "%")
 * strftime() reference:
 * Day of year (%j) code based on Joe Orost's answer:
 * Week number (%V) code based on Taco van den Broek's prototype:
function strftime(sFormat, date) {
  if (!(date instanceof Date)) date = new Date();
  var nDay = date.getDay(),
    nDate = date.getDate(),
    nMonth = date.getMonth(),
    nYear = date.getFullYear(),
    nHour = date.getHours(),
    aDays = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'],
    aMonths = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'],
    aDayCount = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334],
    isLeapYear = function() {
      if (nYear&3!==0) return false;
      return nYear%100!==0 || year%400===0;
    getThursday = function() {
      var target = new Date(date);
      target.setDate(nDate - ((nDay+6)%7) + 3);
      return target;
    zeroPad = function(nNum, nPad) {
      return ('' + (Math.pow(10, nPad) + nNum)).slice(1);
  return sFormat.replace(/%[a-z]/gi, function(sMatch) {
    return {
      '%a': aDays[nDay].slice(0,3),
      '%A': aDays[nDay],
      '%b': aMonths[nMonth].slice(0,3),
      '%B': aMonths[nMonth],
      '%c': date.toUTCString(),
      '%C': Math.floor(nYear/100),
      '%d': zeroPad(nDate, 2),
      '%e': nDate,
      '%F': date.toISOString().slice(0,10),
      '%G': getThursday().getFullYear(),
      '%g': ('' + getThursday().getFullYear()).slice(2),
      '%H': zeroPad(nHour, 2),
      '%I': zeroPad((nHour+11)%12 + 1, 2),
      '%j': zeroPad(aDayCount[nMonth] + nDate + ((nMonth>1 && isLeapYear()) ? 1 : 0), 3),
      '%k': '' + nHour,
      '%l': (nHour+11)%12 + 1,
      '%m': zeroPad(nMonth + 1, 2),
      '%M': zeroPad(date.getMinutes(), 2),
      '%p': (nHour<12) ? 'AM' : 'PM',
      '%P': (nHour<12) ? 'am' : 'pm',
      '%s': Math.round(date.getTime()/1000),
      '%S': zeroPad(date.getSeconds(), 2),
      '%u': nDay || 7,
      '%V': (function() {
              var target = getThursday(),
                n1stThu = target.valueOf();
              target.setMonth(0, 1);
              var nJan1 = target.getDay();
              if (nJan1!==4) target.setMonth(0, 1 + ((4-nJan1)+7)%7);
              return zeroPad(1 + Math.ceil((n1stThu-target)/604800000), 2);
      '%w': '' + nDay,
      '%x': date.toLocaleDateString(),
      '%X': date.toLocaleTimeString(),
      '%y': ('' + nYear).slice(2),
      '%Y': nYear,
      '%z': date.toTimeString().replace(/.+GMT([+-]\d+).+/, '$1'),
      '%Z': date.toTimeString().replace(/.+\((.+?)\)$/, '$1')
    }[sMatch] || sMatch;

Sample usage:

strftime('%F'); // Returns "2016-09-15"
strftime('%A, %B %e, %Y'); // Returns "Thursday, September 15, 2016"

// You can optionally pass it a Date object...

strftime('%x %X', new Date('1/1/2016')); // Returns "1/1/2016 12:00:00 AM"

The latest code is available here:

Java/ JUnit - AssertTrue vs AssertFalse

The course contains a logical error:

    assertTrue("Book check in failed", ml.checkIn(b1));

    assertFalse("Book was aleready checked in", ml.checkIn(b1));

In the first assert we expect the checkIn to return True (because checkin is succesful). If this would fail we would print a message like "book check in failed. Now in the second assert we expect the checkIn to fail, because the book was checked in already in the first line. So we expect a checkIn to return a False. If for some reason checkin returns a True (which we don't expect) than the message should never be "Book was already checked in", because the checkin was succesful.

How do I sort strings alphabetically while accounting for value when a string is numeric?

Value is a string

List = List.OrderBy(c => c.Value.Length).ThenBy(c => c.Value).ToList();


Wheel file installation

You normally use a tool like pip to install wheels. Leave it to the tool to discover and download the file if this is for a project hosted on PyPI.

For this to work, you do need to install the wheel package:

pip install wheel

You can then tell pip to install the project (and it'll download the wheel if available), or the wheel file directly:

pip install project_name  # discover, download and install
pip install wheel_file.whl  # directly install the wheel

The wheel module, once installed, also is runnable from the command line, you can use this to install already-downloaded wheels:

python -m wheel install wheel_file.whl

Also see the wheel project documentation.

How can I show dots ("...") in a span with hidden overflow?

For this you can use text-overflow: ellipsis; property. Write like this

span {_x000D_
    display: inline-block;_x000D_
    width: 180px;_x000D_
    white-space: nowrap;_x000D_
    overflow: hidden !important;_x000D_
    text-overflow: ellipsis;_x000D_
<span>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book</span>


websocket.send() parameter

As I understand it, you want the server be able to send messages through from client 1 to client 2. You cannot directly connect two clients because one of the two ends of a WebSocket connection needs to be a server.

This is some pseudocodish JavaScript:


var websocket = new WebSocket("server address");

websocket.onmessage = function(str) {
  console.log("Someone sent: ", str);

// Tell the server this is client 1 (swap for client 2 of course)
  id: "client1"

// Tell the server we want to send something to the other client
  to: "client2",
  data: "foo"


var clients = {};

server.on("data", function(client, str) {
  var obj = JSON.parse(str);

  if("id" in obj) {
    // New client, add it to the id/client object
    clients[] = client;
  } else {
    // Send data to the client requested

Capturing count from an SQL query

SqlConnection conn = new SqlConnection("ConnectionString");
SqlCommand comm = new SqlCommand("SELECT COUNT(*) FROM table_name", conn);
Int32 count = (Int32) comm .ExecuteScalar();

href="tel:" and mobile numbers

The BlackBerry browser and Safari for iOS (iPhone/iPod/iPad) automatically detect phone numbers and email addresses and convert them to links. If you don’t want this feature, you should use the following meta tags.

For Safari:

<meta name="format-detection" content="telephone=no">

For BlackBerry:

<meta http-equiv="x-rim-auto-match" content="none">


Gulp error: The following tasks did not complete: Did you forget to signal async completion?

Basically v3.X was simpler but v4.x is strict in these means of synchronous & asynchronous tasks.

The async/await is pretty simple & helpful way to understand the workflow & issue.

Use this simple approach

const gulp = require('gulp')

gulp.task('message',async function(){
return console.log('Gulp is running...')

Remove #N/A in vlookup result

To avoid errors in any excel function, use the Error Handling functions that start with IS* in Excel. Embed your function with these error handing functions and avoid the undesirable text in your results. More info in OfficeTricks Page

Ubuntu: OpenJDK 8 - Unable to locate package

I was having the same issue and tried all of the solutions on this page but none of them did the trick.

What finally worked was adding the universe repo to my repo list. To do that run the following command

sudo add-apt-repository universe

After running the above command I was able to run

sudo apt install openjdk-8-jre

without an issue and the package was installed.

Hope this helps someone.

What does it mean by select 1 from table?

The reason is another one, at least for MySQL. This is from the MySQL manual

InnoDB computes index cardinality values for a table the first time that table is accessed after startup, instead of storing such values in the table. This step can take significant time on systems that partition the data into many tables. Since this overhead only applies to the initial table open operation, to “warm up” a table for later use, access it immediately after startup by issuing a statement such as SELECT 1 FROM tbl_name LIMIT 1

Using prepared statements with JDBCTemplate

By default, the JDBCTemplate does its own PreparedStatement internally, if you just use the .update(String sql, Object ... args) form. Spring, and your database, will manage the compiled query for you, so you don't have to worry about opening, closing, resource protection, etc. One of the saving graces of Spring. A link to Spring 2.5's documentation on this. Hope it makes things clearer. Also, statement caching can be done at the JDBC level, as in the case of at least some of Oracle's JDBC drivers. That will go into a lot more detail than I can competently.

How to downgrade Node version

 curl -o- | bash
 sudo npm install -g n
 sudo n 10.15
 npm install
 npm audit fix
 npm start

How to fix Array indexOf() in JavaScript for Internet Explorer browsers

There is Mozilla official solution:

(function() {
    // Production steps of ECMA-262, Edition 5,
    // Reference:
    if (!Array.prototype.indexOf) {
        Array.prototype.indexOf = function(searchElement, fromIndex) {
            var k;
            // 1. Let O be the result of calling ToObject passing
            //    the this value as the argument.
            if (null === this || undefined === this) {
                throw new TypeError('"this" is null or not defined');
            var O = Object(this);
            // 2. Let lenValue be the result of calling the Get
            //    internal method of O with the argument "length".
            // 3. Let len be ToUint32(lenValue).
            var len = O.length >>> 0;
            // 4. If len is 0, return -1.
            if (len === 0) {
                return -1;
            // 5. If argument fromIndex was passed let n be
            //    ToInteger(fromIndex); else let n be 0.
            var n = +fromIndex || 0;
            if (Math.abs(n) === Infinity) {
                n = 0;
            // 6. If n >= len, return -1.
            if (n >= len) {
                return -1;
            // 7. If n >= 0, then Let k be n.
            // 8. Else, n<0, Let k be len - abs(n).
            //    If k is less than 0, then let k be 0.
            k = Math.max(n >= 0 ? n : len - Math.abs(n), 0);
            // 9. Repeat, while k < len
            while (k < len) {
                // a. Let Pk be ToString(k).
                //   This is implicit for LHS operands of the in operator
                // b. Let kPresent be the result of calling the
                //    HasProperty internal method of O with argument Pk.
                //   This step can be combined with c
                // c. If kPresent is true, then
                //    i.  Let elementK be the result of calling the Get
                //        internal method of O with the argument ToString(k).
                //   ii.  Let same be the result of applying the
                //        Strict Equality Comparison Algorithm to
                //        searchElement and elementK.
                //  iii.  If same is true, return k.
                if (k in O && O[k] === searchElement) {
                    return k;
            return -1;

How do I convert an Array to a List<object> in C#?

The List<> constructor can accept anything which implements IEnumerable, therefore...

        object[] testArray = new object[] { "blah", "blah2" };
        List<object> testList = new List<object>(testArray);

Open a new tab on button click in AngularJS

You should use the $location service

Angular docs:

Count length of array and return 1 if it only contains one element

Maybe I am missing something (lots of many-upvotes-members answers here that seem to be looking at this different to I, which would seem implausible that I am correct), but length is not the correct terminology for counting something. Length is usually used to obtain what you are getting, and not what you are wanting.

$cars.count should give you what you seem to be looking for.

Linear Layout and weight in Android

In the width field of button, replace wrap-content with 0dp.
Use layout_weight attribute of a view.


This is how your code will look like:


    android:layout_weight="1" />

    android:text="Not this time"
    android:layout_weight="1" />    


layout_weight is used to distribute the whatever left space into proportions. In this case, the two buttons are taking "0dp" width. So, the remaining space will be divided into 1:1 proportion among them, i.e. the space will be divided equally between the Button Views.

MSSQL Select statement with incremental integer column... not from a table

For SQL 2005 and up

SELECT ROW_NUMBER() OVER( ORDER BY SomeColumn ) AS 'rownumber',*
    FROM YourTable

for 2000 you need to do something like this

INTO #Ranks FROM YourTable WHERE 1=0

SELECT SomeColumn  FROM YourTable
ORDER BY SomeColumn 

Order By Ranks

see also here Row Number

How to find reason of failed Build without any error or warning

Restarting the Visual Studio worked for me. Also try restarting Visual Studio normally (Not Run as Administrator). Try Restarting the System and repeat above step.

Limiting double to 3 decimal places

double example = 3.1416789645;
double output = Convert.ToDouble(example.ToString("N3"));

Angular2 Exception: Can't bind to 'routerLink' since it isn't a known native property

My solution is simple. I am using [href] instead of [routerLink]. I have tried all solutions for [routerLink]. None of them works in my case.

Here is my solution:

<a [href]="getPlanUrl()" target="_blank">My Plan Name</a>

Then write the getPlanUrl function in the TS file.

How do I setup the InternetExplorerDriver so it works

    using System.Text;
    static void Main(String[] args){ 
    var driver =  new InternetExplorerDriver(@"C:\Users\PathToTheFolderContainingIEDriver.exe"); 

You need not include the .exe file. The path to the folder containing the .exe worked for me

Warning: session_start(): Cannot send session cookie - headers already sent by (output started at

Move the session_start(); to top of the page always.


How to get hostname from IP (Linux)?

Another simple way I found for using in LAN is

ssh [username@ip] uname -n

If you need to login command line will be

sshpass -p "[password]" ssh [username@ip] uname -n

Disable eslint rules for folder

The previous answers were in the right track, but the complete answer for this is going to Disabling rules only for a group of files, there you'll find the documentation needed to disable/enable rules for certain folders (Because in some cases you don't want to ignore the whole thing, only disable certain rules). Example:

    "env": {},
    "extends": [],
    "parser": "",
    "plugins": [],
    "rules": {},
    "overrides": [
        "files": ["test/*.spec.js"], // Or *.test.js
        "rules": {
          "require-jsdoc": "off"
    "settings": {}

Writing an Excel file in EPPlus

It's best if you worked with DataSets and/or DataTables. Once you have that, ideally straight from your stored procedure with proper column names for headers, you can use the following method:

ws.Cells.LoadFromDataTable(<DATATABLE HERE>, true, OfficeOpenXml.Table.TableStyles.Light8);

.. which will produce a beautiful excelsheet with a nice table!

Now to serve your file, assuming you have an ExcelPackage object as in your code above called pck..


Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.AddHeader("Content-Disposition", "attachment;filename=" + sFilename);


How to trim a string to N chars in Javascript?

Just another suggestion, removing any trailing white-space

limitStrLength = (text, max_length) => {
    if(text.length > max_length - 3){
        return text.substring(0, max_length).trimEnd() + "..."
        return text

Math constant PI value in C

anyway you have not a unlimited accuracy so C define a constant in this way:

#define PI 3.14159265358979323846

import math.h to use this


It's worth to mention that CLOB / BLOB data types and their sizes are supported by MySQL 5.0+, so you can choose the proper data type for your need.

Data Type   Date Type   Storage Required
(CLOB)      (BLOB)

TINYTEXT    TINYBLOB    L + 1 bytes, where L < 2**8  (255)
TEXT        BLOB        L + 2 bytes, where L < 2**16 (64 K)
MEDIUMTEXT  MEDIUMBLOB  L + 3 bytes, where L < 2**24 (16 MB)
LONGTEXT    LONGBLOB    L + 4 bytes, where L < 2**32 (4 GB)

where L stands for the byte length of a string

JQuery Ajax Post results in 500 Internal Server Error

A 500 from ASP.NET probably means an unhandled exception was thrown at some point when serving the request.

I suggest you attach a debugger to the web server process (assuming you have access).

One strange thing: You make a POST request to the server, but you do not pass any data (everything is in the query string). Perhaps it should be a GET request instead?

You should also double check that the URL is correct.

Is it safe to use Project Lombok?

I haven't tried using Lombok yet - it is/was next on my list, but it sounds as if Java 8 has caused significant problems for it, and remedial work was still in progress as of a week ago. My source for that is .

Xcode 'CodeSign error: code signing is required'

Maybe your mac's date and time are incorrect. Just correct them.

How do I format a date in Jinja2?

I think you have to write your own filter for that. It's actually the example for custom filters in the documentation:

Run a Command Prompt command from Desktop Shortcut

Yes, make the shortcut's path

%comspec% /k <command>


  • %comspec% is the environment variable for cmd.exe's full path, equivalent to C:\Windows\System32\cmd.exe on most (if not all) Windows installs
  • /k keeps the window open after the command has run, this may be replaced with /c if you want the window to close once the command is finished running
  • <command> is the command you wish to run

jQuery find element by data attribute value

you can also use andSelf() method to get wrapper DOM contain then find() can be work around as your idea

$(function() {_x000D_
.active {_x000D_
  background: green;_x000D_
<script src=""></script>_x000D_
<a class="slide-link" href="#" data-slide="0">1</a>_x000D_
<a class="slide-link" href="#" data-slide="1">2</a>_x000D_
<a class="slide-link" href="#" data-slide="2">3</a>

Commands out of sync; you can't run this command now

Once you used


You MAY close it to use another query.


This problem was hunting me for hours. Hopefully, it will fix yours.

How to delete parent element using jQuery

what about using unwrap()

<div class="parent">
<p class="child">

after using - $(".child").unwrap() - it will be;

<p class="child">

Two Decimal places using c#

Another way :

decimal.Round(decimalvalue, 2, MidpointRounding.AwayFromZero);

Powershell equivalent of bash ampersand (&) for forking/running background processes

From PowerShell Core 6.0 you are able to write & at end of command and it will be equivalent to running you pipeline in background in current working directory.

It's not equivalent to & in bash, it's just a nicer syntax for current PowerShell jobs feature. It returns a job object so you can use all other command that you would use for jobs. For example Receive-Job:

C:\utils> ping &

Id     Name            PSJobTypeName   State         HasMoreData     Location             Command
--     ----            -------------   -----         -----------     --------             -------
35     Job35           BackgroundJob   Running       True            localhost            Microsoft.PowerShell.M...

C:\utils> Receive-Job 35

Pinging [] with 32 bytes of data:
Reply from bytes=32 time=11ms TTL=55
Reply from bytes=32 time=11ms TTL=55
Reply from bytes=32 time=10ms TTL=55
Reply from bytes=32 time=10ms TTL=55

Ping statistics for
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 10ms, Maximum = 11ms, Average = 10ms

If you want to execute couple of statements in background you can combine & call operator, { } script block and this new & background operator like here:

& { cd .\SomeDir\; .\SomeLongRunningOperation.bat; cd ..; } &

Here's some more info from documentation pages:

from What's New in PowerShell Core 6.0:

Support backgrounding of pipelines with ampersand (&) (#3360)

Putting & at the end of a pipeline causes the pipeline to be run as a PowerShell job. When a pipeline is backgrounded, a job object is returned. Once the pipeline is running as a job, all of the standard *-Job cmdlets can be used to manage the job. Variables (ignoring process-specific variables) used in the pipeline are automatically copied to the job so Copy-Item $foo $bar & just works. The job is also run in the current directory instead of the user's home directory. For more information about PowerShell jobs, see about_Jobs.

from about_operators / Ampersand background operator &:

Ampersand background operator &

Runs the pipeline before it in a PowerShell job. The ampersand background operator acts similarly to the UNIX "ampersand operator" which famously runs the command before it as a background process. The ampersand background operator is built on top of PowerShell jobs so it shares a lot of functionality with Start-Job. The following command contains basic usage of the ampersand background operator.

Get-Process -Name pwsh &

This is functionally equivalent to the following usage of Start-Job.

Start-Job -ScriptBlock {Get-Process -Name pwsh}

Since it's functionally equivalent to using Start-Job, the ampersand background operator returns a Job object just like Start-Job does. This means that you are able to use Receive-Job and Remove-Job just as you would if you had used Start-Job to start the job.

$job = Get-Process -Name pwsh &
Receive-Job $job


NPM(K)    PM(M)      WS(M)     CPU(s)      Id  SI ProcessName
------    -----      -----     ------      --  -- -----------
    0     0.00     221.16      25.90    6988 988 pwsh
    0     0.00     140.12      29.87   14845 845 pwsh
    0     0.00      85.51       0.91   19639 988 pwsh

$job = Get-Process -Name pwsh &
Remove-Job $job

For more information on PowerShell jobs, see about_Jobs.

How to rename array keys in PHP?

Very simple approach to replace keys in a multidimensional array, and maybe even a bit dangerous, but should work fine if you have some kind of control over the source array:

$array = [ 'oldkey' => [ 'oldkey' => 'wow'] ];
$new_array = json_decode(str_replace('"oldkey":', '"newkey":', json_encode($array)));
print_r($new_array); // [ 'newkey' => [ 'newkey' => 'wow'] ]

Where in memory are my variables stored in C?

One thing one needs to keep in mind about the storage is the as-if rule. The compiler is not required to put a variable in a specific place - instead it can place it wherever it pleases for as long as the compiled program behaves as if it were run in the abstract C machine according to the rules of the abstract C machine. This applies to all storage durations. For example:

  • a variable that is not accessed all can be eliminated completely - it has no storage... anywhere. Example - see how there is 42 in the generated assembly code but no sign of 404.
  • a variable with automatic storage duration that does not have its address taken need not be stored in memory at all. An example would be a loop variable.
  • a variable that is const or effectively const need not be in memory. Example - the compiler can prove that foo is effectively const and inlines its use into the code. bar has external linkage and the compiler cannot prove that it would not be changed outside the current module, hence it is not inlined.
  • an object allocated with malloc need not reside in memory allocated from heap! Example - notice how the code does not have a call to malloc and neither is the value 42 ever stored in memory, it is kept in a register!
  • thus an object that has been allocated by malloc and the reference is lost without deallocating the object with free need not leak memory...
  • the object allocated by malloc need not be within the heap below the program break (sbrk(0)) on Unixen...

How to create an Explorer-like folder browser control?

Take a look at Shell MegaPack control set. It provides Windows Explorer like folder/file browsing with most of the features and functionality like context menus, renaming, drag-drop, icons, overlay icons, thumbnails, etc

Laravel 5.4 create model, controller and migration in single artisan command

Just Try this command on your terminal

php artisan make:model Todo -mcr

Below the output and your Model, Controller with Resource and Migration file will create...

Model created successfully.
Created Migration: 2019_12_25_105305_create_todos_table
Controller created successfully.

Wait .5 seconds before continuing code

The suggested Code is flawed:

Imports VB = Microsoft.VisualBasic

Public Sub wait(ByVal seconds As Single)
    Static start As Single
    start = VB.Timer()
    Do While VB.Timer() < start + seconds
End Sub

VB.Timer() returns the seconds since midnight. If this is called just before midnight the break will be nearly a full day. I would suggest the following:

Private Sub Wait(ByVal Seconds As Double, Optional ByRef BreakCondition As Boolean = False)
    Dim l_WaitUntil As Date
    l_WaitUntil = Now.AddSeconds(Seconds)
    Do Until Now > l_WaitUntil
        If BreakCondition Then Exit Do
End Sub

BreakCondition can be set to true when the waitloop should be cancelled as DoEvents is called this can be done from outside the loop.

Setting different color for each series in scatter plot on matplotlib

This works for me:

for each series, use a random rgb colour generator

c = color[np.random.random_sample(), np.random.random_sample(), np.random.random_sample()]

How to specify jackson to only use fields - preferably globally

Specifically for boolean is*() getters:

I've spend a lot of time on why neither below

  @JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE)

nor this

  setVisibility(PropertyAccessor.SETTER, JsonAutoDetect.Visibility.NONE);
  setVisibility(PropertyAccessor.GETTER, JsonAutoDetect.Visibility.NONE);
  setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);

worked for my Boolean Getter/Setter.

Solution is simple:

  @JsonAutoDetect(isGetterVisibility = Visibility.NONE, ...          
  setVisibility(PropertyAccessor.IS_GETTER, JsonAutoDetect.Visibility.NONE);

UPDATE: spring-boot allowed configure it:

  visibility.field: any
  visibility.getter: none
  visibility.setter: none none

See Common application properties # JACKSON

How to compare two List<String> to each other?

You could also use Except(produces the set difference of two sequences) to check whether there's a difference or not:

IEnumerable<string> inFirstOnly = a1.Except(a2);
IEnumerable<string> inSecondOnly = a2.Except(a1);
bool allInBoth = !inFirstOnly.Any() && !inSecondOnly.Any();

So this is an efficient way if the order and if the number of duplicates does not matter(as opposed to the accepted answer's SequenceEqual). Demo: Ideone

If you want to compare in a case insentive way, just add StringComparer.OrdinalIgnoreCase:

a1.Except(a2, StringComparer.OrdinalIgnoreCase)

How do I merge changes to a single file, rather than merging commits?

git checkout <target_branch>
git checkout <source_branch> <file_path>

Email Address Validation in Android on EditText

public static boolean isEmailValid(String email) {
    boolean isValid = false;

    String expression = "^[\\w\\.-]+@([\\w\\-]+\\.)+[A-Z]{2,4}$";
    CharSequence inputStr = email;

    Pattern pattern = Pattern.compile(expression, Pattern.CASE_INSENSITIVE);
    Matcher matcher = pattern.matcher(inputStr);
    if (matcher.matches()) {
        isValid = true;
    return isValid;

Is there a Social Security Number reserved for testing/examples?

Please look at this document

The SSA is instituting a new policy the where all previously unused sequences are will be available for use.

Goes into affect June 25, 2011.

Taken from the new FAQ:

What changes will result from randomization?

The SSA will eliminate the geographical significance of the first three digits of the SSN, currently referred to as the area number, by no longer allocating the area numbers for assignment to individuals in specific states. The significance of the highest group number (the fourth and fifth digits of the SSN) for validation purposes will be eliminated. Randomization will also introduce previously unassigned area numbers for assignment excluding area numbers 000, 666 and 900-999. Top

Will SSN randomization assign group number (the fourth and fifth digits of the SSN) 00 or serial number (the last four digits of the SSN) 0000?

SSN randomization will not assign group number 00 or serial number 0000. SSNs containing group number 00 or serial number 0000 will continue to be invalid.

What is Activity.finish() method doing exactly?

@user3282164 According to the Activity life-cycle it should go through onPause() -> onStop() -> onDestroy() upon calling finish().

The diagram does not show any straight path from [Activity Running] to [onDestroy()] caused by the system.

onStop() doc says "Note that this method may never be called, in low memory situations where the system does not have enough memory to keep your activity's process running after its onPause() method is called."

How to declare a structure in a header that is to be used by multiple files in c?

For a structure definition that is to be used across more than one source file, you should definitely put it in a header file. Then include that header file in any source file that needs the structure.

The extern declaration is not used for structure definitions, but is instead used for variable declarations (that is, some data value with a structure type that you have defined). If you want to use the same variable across more than one source file, declare it as extern in a header file like:

extern struct a myAValue;

Then, in one source file, define the actual variable:

struct a myAValue;

If you forget to do this or accidentally define it in two source files, the linker will let you know about this.

How to make a 3D scatter plot in Python?

Use the following code it worked for me:

# Create the figure
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')

# Generate the values
x_vals = X_iso[:, 0:1]
y_vals = X_iso[:, 1:2]
z_vals = X_iso[:, 2:3]

# Plot the values
ax.scatter(x_vals, y_vals, z_vals, c = 'b', marker='o')

while X_iso is my 3-D array and for X_vals, Y_vals, Z_vals I copied/used 1 column/axis from that array and assigned to those variables/arrays respectively.

IntelliJ IDEA shows errors when using Spring's @Autowired annotation

Got the same error here!

It seems the Intellij cannot verify if the class implementation is a @Service or @Component.

Solve it just changing from Error to Warning(Pressing Alt + Enter).

Custom method names in ASP.NET Web API

I am days into the MVC4 world.

For what its worth, I have a SitesAPIController, and I needed a custom method, that could be called like:


With different values for the last parameter to get record with different dispositions.

What Finally worked for me was:

The method in the SitesAPIController:

// GET api/SitesAPI/Disposition/1
public Site Disposition(int disposition)
    Site site = db.Sites.Where(s => s.Disposition == disposition).First();
    return site;

And this in the WebApiConfig.cs

// this was already there
    name: "DefaultApi",
    routeTemplate: "api/{controller}/{id}",
    defaults: new { id = RouteParameter.Optional }

// this i added
    name: "Action",
    routeTemplate: "api/{controller}/{action}/{disposition}"

For as long as I was naming the {disposition} as {id} i was encountering:

"Message": "No HTTP resource was found that matches the request URI 'http://localhost:9000/api/SitesAPI/Disposition/0'.",
"MessageDetail": "No action was found on the controller 'SitesAPI' that matches the request."

When I renamed it to {disposition} it started working. So apparently the parameter name is matched with the value in the placeholder.

Feel free to edit this answer to make it more accurate/explanatory.

Android: How do I prevent the soft keyboard from pushing my view up?

To do this programatically in a fragment you can use following code


Place this in onResume()

What is the difference between JOIN and UNION?

Joins and Unions can be used to combine data from one or more tables. The difference lies in how the data is combined.

In simple terms, joins combine data into new columns. If two tables are joined together, then the data from the first table is shown in one set of column alongside the second table’s column in the same row.

Unions combine data into new rows. If two tables are “unioned” together, then the data from the first table is in one set of rows, and the data from the second table in another set. The rows are in the same result.

Here is a visual depiction of a join. Table A and B’s columns are combined into a single result.

enter image description here

Each row in the result contains columns from BOTH table A and B. Rows are created when columns from one table match columns from another. This match is called the join condition.

This makes joins really great for looking up values and including them in results. This is usually the result of denormalizing (reversing normalization) and involves using the foreign key in one table to look up column values by using the primary key in another.

Now compare the above depiction with that of a union. In a union each row within the result is from one table OR the other. In a union, columns aren’t combined to create results, rows are combined.

enter image description here

Both joins and unions can be used to combine data from one or more tables into a single results. They both go about this is different ways. Whereas a join is used to combine columns from different tables, the union is used to combine rows.


TypeError: p.easing[this.easing] is not a function

I got this error today whilst trying to initiate a slide effect on a div. Thanks to the answer from 'I Hate Lazy' above (which I've upvoted), I went looking for a custom jQuery UI script, and you can in fact build your own file directly on the jQuery ui website All you have to do is mark the effect(s) that you're looking for and then download.

I was looking for the slide effect. So I first unchecked all the checkboxes, then clicked on the 'slide effect' checkbox and the page automatically then checks those other components necessary to make the slide effect work. Very simple.

easeOutBounce is an easing effect, for which you'll need to check the 'Effects Core' checkbox.

Connecting to SQL Server with Visual Studio Express Editions

The only way I was able to get C# Express 2008 to work was to move the database file. So, I opened up SQL Server Management Studio and after dropping the database, I copied the file to my project folder. Then I reattached the database to management studio. Now, when I try to attach to the local copy it works. Apparently, you can not use the same database file more than once.

How to properly add cross-site request forgery (CSRF) token using PHP

Security Warning: md5(uniqid(rand(), TRUE)) is not a secure way to generate random numbers. See this answer for more information and a solution that leverages a cryptographically secure random number generator.

Looks like you need an else with your if.

if (!isset($_SESSION['token'])) {
    $token = md5(uniqid(rand(), TRUE));
    $_SESSION['token'] = $token;
    $_SESSION['token_time'] = time();
    $token = $_SESSION['token'];

Add context path to Spring Boot application

You can do it by adding the port and contextpath easily to add the configuration in [src\main\resources] .properties file and also .yml file

application.porperties file configuration

server.port = 8084
server.contextPath = /context-path

application.yml file configuration

port: 8084
contextPath: /context-path

We can also change it programmatically in spring boot.

public class ServerPortCustomizer implements     WebServerFactoryCustomizer<EmbeddedServletContainerCustomizer > {

public void customize(EmbeddedServletContainerCustomizer factory) {


We can also add an other way

public class MyApplication {
public static void main(String[] args) {SpringApplication application =     new pringApplication(MyApplication.class);
    Map<String, Object> map = new HashMap<>();
    map.put("server.servlet.context-path", "/context-path");
    map.put("server.port", "808");

using java command spring boot 1.X

java -jar my-app.jar --server.contextPath=/spring-boot-app     --server.port=8585 

using java command spring boot 2.X

java -jar my-app.jar --server.servlet.context-path=/spring-boot-app --server.port=8585 

Is there a difference between /\s/g and /\s+/g?

\s means "one space", and \s+ means "one or more spaces".

But, because you're using the /g flag (replace all occurrences) and replacing with the empty string, your two expressions have the same effect.

How to loop through an associative array and get the key?

Nobody answered with regular for loop? Sometimes I find it more readable and prefer for over foreach
So here it is:

$array = array('key1' => 'value1', 'key2' => 'value2'); 

$keys = array_keys($array);

for($i=0; $i < count($keys); ++$i) {
    echo $keys[$i] . ' ' . $array[$keys[$i]] . "\n";

  key1 value1
  key2 value2

Do a "git export" (like "svn export")?

For GitHub users, the git archive --remote method won't work directly, as the export URL is ephemeral. You must ask GitHub for the URL, then download that URL. curl makes that easy:

curl -L | tar xzf -

This will give you the exported code in a local directory. Example:

$ curl -L | tar xzf -
$ ls jpic-bashworks-34f4441/
break  conf  docs  hack  LICENSE  mlog  module  mpd  mtests  os  README.rst  remote  todo  vcs  vps  wepcrack

If you want the code put into a specific, existing directory (rather than the random one from github):

curl -L | \
tar xzC /path/you/want --strip 1

Converting int to string in C

If you really want to use itoa, you need to include the standard library header.

#include <stdlib.h>

I also believe that if you're on Windows (using MSVC), then itoa is actually _itoa.


Then again, since you're getting a message from collect2, you're likely running GCC on *nix.

Inserting a blank table row with a smaller height

I know this question already has an answer, but I found out an even simpler way of doing this.

Just add

<tr height = 20px></tr>

Into the table where you want to have an empty row. It works fine in my program and it's probably the quickest solution possible.

Checking network connection

Here's my version

import requests

    if requests.get('').ok:
        print("You're Online")
    print("You're Offline")

How can the size of an input text box be defined in HTML?

<input size="45" type="text" name="name">

The "size" specifies the visible width in characters of the element input.

You can also use the height and width from css.

<input type="text" name="name" style="height:100px; width:300px;">

SQL Server PRINT SELECT (Print a select query result)?

If you want to print multiple rows, you can iterate through the result by using a cursor. e.g. print all names from sys.database_principals

DECLARE @name nvarchar(128)

SELECT name FROM sys.database_principals

OPEN cur

PRINT @name

CLOSE cur;

Are 64 bit programs bigger and faster than 32 bit versions?

Any applications that require CPU usage such as transcoding, display performance and media rendering, whether it be audio or visual, will certainly require (at this point) and benefit from using 64 bit versus 32 bit due to the CPU's ability to deal with the sheer amount of data being thrown at it. It's not so much a question of address space as it is the way the data is being dealt with. A 64 bit processor, given 64 bit code, is going to perform better, especially with mathematically difficult things like transcoding and VoIP data - in fact, any sort of 'math' applications should benefit by the usage of 64 bit CPUs and operating systems. Prove me wrong.

Detect Scroll Up & Scroll down in ListView

            ListView listView = getListView();
            listView.setOnScrollListener(new OnScrollListener() {

                public void onScrollStateChanged(AbsListView view, int scrollState) {

                    view.setOnTouchListener(new OnTouchListener() {
                        private float mInitialX;
                        private float mInitialY;

                        public boolean onTouch(View v, MotionEvent event) {
                            switch (event.getAction()) {
                                case MotionEvent.ACTION_DOWN:
                                    mInitialX = event.getX();
                                    mInitialY = event.getY();
                                    return true;
                                case MotionEvent.ACTION_MOVE:
                                    final float x = event.getX();
                                    final float y = event.getY();
                                    final float yDiff = y - mInitialY;
                                    if (yDiff > 0.0) {
                                        Log.d(tag, "SCROLL DOWN");
                                        scrollDown = true;

                                    } else if (yDiff < 0.0) {
                                        Log.d(tag, "SCROLL up");
                                        scrollDown = true;

                            return false;

Git push rejected "non-fast-forward"

I'm late to the party but I found some useful instructions in github help page and I wanted to share them here.

Sometimes, Git can't make your change to a remote repository without losing commits. When this happens, your push is refused.

If another person has pushed to the same branch as you, Git won't be able to push your changes:

$ git push origin master
 ! [rejected]        master -> master (non-fast-forward)
error: failed to push some refs to ''
To prevent you from losing history, non-fast-forward updates were rejected
Merge the remote changes (e.g. 'git pull') before pushing again.  See the
'Note about fast-forwards' section of 'git push --help' for details.

You can fix this by fetching and merging the changes made on the remote branch with the changes that you have made locally:

$ git fetch origin
# Fetches updates made to an online repository
$ git merge origin YOUR_BRANCH_NAME
# Merges updates made online with your local work

Or, you can simply use git pull to perform both commands at once:

$ git pull origin YOUR_BRANCH_NAME
# Grabs online updates and merges them with your local work

Telegram Bot - how to get a group chat id?

You can get Chat ID in this way.

On private chat with your bot, send a random message. You will search this message later.


Then, on your browser make a request with that url :

The request returns a json response, in json text search your random message and get chat id in that object.

Replacing accented characters php

So I found this on page for preg_replace function

// replace accented chars

$string = "Zacarías Ferreíra"; // my definition for string variable
$accents = '/&([A-Za-z]{1,2})(grave|acute|circ|cedil|uml|lig);/';

$string_encoded = htmlentities($string,ENT_NOQUOTES,'UTF-8');

$string = preg_replace($accents,'$1',$string_encoded);

If you have encoding issues you may get someting like this "Zacarías Ferreíra", just decode the string and use said code above

$string = utf8_decode("Zacarías Ferreíra");

Where is the file in a Spring Boot project?

In the your first journey in spring boot project I recommend you to start with Spring Starter Try this link here.

enter image description here

It will auto generate the project structure for you like this.application.perperties it will be under /resources. important change,

server.port = Your PORT(XXXX) by default=8080
server.servlet.context-path=/api (SpringBoot version 2.x.)
server.contextPath-path=/api (SpringBoot version < 2.x.)

Any way you can use application.yml in case you don't want to make redundancy properties setting.


   port: 8080 
   contextPath: /api

server.port = 8080
server.contextPath = /api

Show DataFrame as table in iPython Notebook

It seems you can just display both dfs using a comma in between in display. I noticed this on some notebooks on github. This code is from Jake VanderPlas's notebook.

class display(object):
    """Display HTML representation of multiple objects"""
    template = """<div style="float: left; padding: 10px;">
    <p style='font-family:"Courier New", Courier, monospace'>{0}</p>{1}
    def __init__(self, *args):
        self.args = args

    def _repr_html_(self):
        return '\n'.join(self.template.format(a, eval(a)._repr_html_())
                     for a in self.args)

    def __repr__(self):
        return '\n\n'.join(a + '\n' + repr(eval(a))
                       for a in self.args)

display('df', "df2")

how to show alternate image if source image is not found? (onerror working in IE but not in mozilla)

If you're open to a PHP solution:

<td><img src='<?PHP
  $path1 = "path/to/your/image.jpg";
  $path2 = "alternate/path/to/another/image.jpg";

  echo file_exists($path1) ? $path1 : $path2; 
  ?>' alt='' />

////EDIT OK, here's a JS version:

<td><img src='' id='myImage' /></td>

<script type='text/javascript'>
  document.getElementById('myImage').src = "newImage.png";

  document.getElementById('myImage').onload = function() { 

  document.getElementById('myImage').onerror = function() { 
    alert("Inserting alternate");
    document.getElementById('myImage').src = "alternate.png"; 

How do I update Ruby Gems from behind a Proxy (ISA-NTLM)

If you want to use SOCKS5 proxy, you may try rubygems-socksproxy

It works for me on OSX 10.9.3.

npm WARN enoent ENOENT: no such file or directory, open 'C:\Users\Nuwanst\package.json'

finally, I got a solution if you are getting:-

**npm WARN tar ENOENT: no such file or directory,.......**

then it is no issue of npm or its version it is os permission issue to resolve this you need to use below command:-

sudo chown -R $USER:$USER *


sudo chmod -R 777 *

then run:-

sudo npm i 

how to set the query timeout from SQL connection string

you can set Timeout in connection string (time for Establish connection between client and sql). commandTimeout is set per command but its default time is 30 secend

Insert, on duplicate update in PostgreSQL?

PostgreSQL since version 9.5 has UPSERT syntax, with ON CONFLICT clause. with the following syntax (similar to MySQL)

INSERT INTO the_table (id, column_1, column_2) 
VALUES (1, 'A', 'X'), (2, 'B', 'Y'), (3, 'C', 'Z')
  SET column_1 = excluded.column_1, 
      column_2 = excluded.column_2;

Searching postgresql's email group archives for "upsert" leads to finding an example of doing what you possibly want to do, in the manual:

Example 38-2. Exceptions with UPDATE/INSERT

This example uses exception handling to perform either UPDATE or INSERT, as appropriate:


        -- first try to update the key
        -- note that "a" must be unique
        UPDATE db SET b = data WHERE a = key;
        IF found THEN
        END IF;
        -- not there, so try to insert the key
        -- if someone else inserts the same key concurrently,
        -- we could get a unique-key failure
            INSERT INTO db(a,b) VALUES (key, data);
        EXCEPTION WHEN unique_violation THEN
            -- do nothing, and loop to try the UPDATE again
LANGUAGE plpgsql;

SELECT merge_db(1, 'david');
SELECT merge_db(1, 'dennis');

There's possibly an example of how to do this in bulk, using CTEs in 9.1 and above, in the hackers mailing list:

WITH foos AS (SELECT (UNNEST(%foo[])).*)
updated as (UPDATE foo SET foo.a = foos.a ... RETURNING
INSERT INTO foo SELECT foos.* FROM foos LEFT JOIN updated USING(id)

See a_horse_with_no_name's answer for a clearer example.

How to set time zone of a java.util.Date?

You could also set the timezone at the JVM level

Date date1 = new Date();

// or pass in a command line arg: -Duser.timezone="UTC"

Date date2 = new Date();


Thu Sep 05 10:11:12 EDT 2013
Thu Sep 05 14:11:12 UTC 2013

JavaFX How to set scene background image

In addition to @Elltz answer, we can use both fill and image for background:

            new Background(
                    Collections.singletonList(new BackgroundFill(
                            new CornerRadii(500), 
                            new Insets(10))),
                    Collections.singletonList(new BackgroundImage(
                            new Image("image/logo.png", 100, 100, false, true),


                new Background(
                        Collections.singletonList(new BackgroundFill(
                                new CornerRadii(0),
                                new Insets(0))),
                        Collections.singletonList(new BackgroundImage(
                                new Image("file:clouds.jpg", 100, 100, false, true),
                                new BackgroundSize(1.0, 1.0, true, true, false, false)

(different last argument) to make the image full-window size.

Use of document.getElementById in JavaScript

Here in your code demo is id where you want to display your result after click event has occur and just nothing.

You can take anything

<p id="demo">


<div id="demo"> 

It is just node in a document where you just want to display your result.

Install Windows Service created in Visual Studio

Another possible problem (which I ran into):

Be sure that the ProjectInstaller class is public. To be honest, I am not sure how exactly I did it, but I added event handlers to ProjectInstaller.Designer.cs, like:

this.serviceProcessInstaller1.BeforeInstall += new System.Configuration.Install.InstallEventHandler(this.serviceProcessInstaller1_BeforeInstall);

I guess during the automatical process of creating the handler function in ProjectInstaller.cs it changed the class definition from

public class ProjectInstaller : System.Configuration.Install.Installer


partial class ProjectInstaller : System.Configuration.Install.Installer

replacing the public keyword with partial. So, in order to fix it it must be

public partial class ProjectInstaller : System.Configuration.Install.Installer

I use Visual Studio 2013 Community edition.

Local storage in Angular 2

Here is an example of a simple service, that uses localStorage to persist data:

import { Injectable } from '@angular/core';

export class PersistanceService {
  constructor() {}

  set(key: string, data: any): void {
    try {
      localStorage.setItem(key, JSON.stringify(data));
    } catch (e) {
      console.error('Error saving to localStorage', e);

  get(key: string) {
    try {
      return JSON.parse(localStorage.getItem(key));
    } catch (e) {
      console.error('Error getting data from localStorage', e);
      return null;

To use this services, provide it in some module in your app like normal, for example in core module. Then use like this:

import { Injectable } from '@angular/core';

export class SomeOtherService {

  constructor(private persister: PersistanceService) {}

  someMethod() {
    const myData = {foo: 'bar'};
    persister.set('SOME_KEY', myData);

  someOtherMethod() {
    const myData = persister.get('SOME_KEY');

WAMP error: Forbidden You don't have permission to access /phpmyadmin/ on this server

For Apache 2.4.2 the solution is: in httpd.conf on line 265 change Require none to Require all granted. That's all.

Python initializing a list of lists

The problem is that they're all the same exact list in memory. When you use the [x]*n syntax, what you get is a list of n many x objects, but they're all references to the same object. They're not distinct instances, rather, just n references to the same instance.

To make a list of 3 different lists, do this:

x = [[] for i in range(3)]

This gives you 3 separate instances of [], which is what you want

[[]]*n is similar to

l = []
x = []
for i in range(n):

While [[] for i in range(3)] is similar to:

x = []
for i in range(n):
    x.append([])   # appending a new list!

In [20]: x = [[]] * 4

In [21]: [id(i) for i in x]
Out[21]: [164363948, 164363948, 164363948, 164363948] # same id()'s for each list,i.e same object

In [22]: x=[[] for i in range(4)]

In [23]: [id(i) for i in x]
Out[23]: [164382060, 164364140, 164363628, 164381292] #different id(), i.e unique objects this time

How can I bold the fonts of a specific row or cell in an Excel worksheet with C#?

How to Bold entire row 10 example:

workSheet.Cells[10, 1].EntireRow.Font.Bold = true;    

More formally:

Microsoft.Office.Interop.Excel.Range rng = workSheet.Cells[10, 1] as Xl.Range;
rng.EntireRow.Font.Bold = true;

How to Bold Specific Cell 'A10' for example:

workSheet.Cells[10, 1].Font.Bold = true;

Little more formal:

int row = 1;
int column = 1;  /// 1 = 'A' in Excel

Microsoft.Office.Interop.Excel.Range rng = workSheet.Cells[row, column] as Xl.Range;
rng.Font.Bold = true;

How do I view the SSIS packages in SQL Server Management Studio?

  1. Open SQL server Management Studio.
  2. Go to Connect to Server and select the Server Type as Integration Services and give the Server Name then click connect.
  3. Go to Object Explorer on the left corner.
  4. You can see the Stored Package folder in Object Explorer.
  5. Expand the Stored Package folder, here you can see the SSIS interfaces.

How do I check if a file exists in Java?

Don't. Just catch the FileNotFoundException. The file system has to test whether the file exists anyway. There is no point in doing all that twice, and several reasons not to, such as:

  • double the code
  • the timing window problem whereby the file might exist when you test but not when you open, or vice versa, and
  • the fact that, as the existence of this question shows, you might make the wrong test and get the wrong answer.

Don't try to second-guess the system. It knows. And don't try to predict the future. In general the best way to test whether any resource is available is just to try to use it.

How to print a float with 2 decimal places in Java?

Just do String str = System.out.printf("%.2f", val).replace(",", "."); if you want to ensure that independently of the Locale of the user, you will always get / display a "." as decimal separator. This is a must if you don't want to make your program crash if you later do some kind of conversion like float f = Float.parseFloat(str);

How do I restart a program based on user input?

You can do this simply with a function. For example:

def script():
    # program code here...
    restart = raw_input("Would you like to restart this program?")
    if restart == "yes" or restart == "y":
    if restart == "n" or restart == "no":
        print "Script terminating. Goodbye."

Of course you can change a lot of things here. What is said, what the script will accept as a valid input, the variable and function names. You can simply nest the entire program in a user-defined function (Of course you must give everything inside an extra indent) and have it restart at anytime using this line of code: myfunctionname(). More on this here.

Pyspark: Exception: Java gateway process exited before sending the driver its port number

I go this error fixed by using the below code. I had setup the SPARK_HOME though. You may follow this simple steps from eproblems website

spark_home = os.environ.get('SPARK_HOME', None)

Define: What is a HashSet?

A HashSet has an internal structure (hash), where items can be searched and identified quickly. The downside is that iterating through a HashSet (or getting an item by index) is rather slow.

So why would someone want be able to know if an entry already exists in a set?

One situation where a HashSet is useful is in getting distinct values from a list where duplicates may exist. Once an item is added to the HashSet it is quick to determine if the item exists (Contains operator).

Other advantages of the HashSet are the Set operations: IntersectWith, IsSubsetOf, IsSupersetOf, Overlaps, SymmetricExceptWith, UnionWith.

If you are familiar with the object constraint language then you will identify these set operations. You will also see that it is one step closer to an implementation of executable UML.

How can I draw circle through XML Drawable - Android?

no need for the padding or the corners.

here's a sample:

<shape xmlns:android="" android:shape="oval" >
    <gradient android:startColor="#FFFF0000" android:endColor="#80FF00FF"

based on :

How do I fix PyDev "Undefined variable from import" errors?

I'm using opencv which relies on binaries etc so I have scripts where every other line has this silly error. Python is a dynamic language so such occasions shouldn't be considered errors.

I removed these errors altogether by going to:

Window -> Preferences -> PyDev -> Editor -> Code Analysis -> Undefined -> Undefined Variable From Import -> Ignore

And that's that.

It may also be, Window -> Preferences -> PyDev -> Editor -> Code Analysis -> Imports -> Import not found -> Ignore

SQL Query to concatenate column values from multiple rows in Oracle

With SQL model clause:

SQL> select pid
  2       , ltrim(sentence) sentence
  3    from ( select pid
  4                , seq
  5                , sentence
  6             from b
  7            model
  8                  partition by (pid)
  9                  dimension by (seq)
 10                  measures (descr,cast(null as varchar2(100)) as sentence)
 11                  ( sentence[any] order by seq desc
 12                    = descr[cv()] || ' ' || sentence[cv()+1]
 13                  )
 14         )
 15   where seq = 1
 16  /

- ---------------------------------------------------------------------------
A Have a nice day
B Nice Work.
C Yes we can do this work!

3 rows selected.

I wrote about this here. And if you follow the link to the OTN-thread you will find some more, including a performance comparison.

How to stick a footer to bottom in css?

#Footer {

That will make the footer stay at the bottom of the browser window no matter where you scroll.

OpenCV !_src.empty() in function 'cvtColor' error

Your code can't find the figure or the name of your figure named the by error message. Solution:

import cv2
import numpy as np 
import matplotlib.pyplot as plt 

This table does not contain a unique column. Grid edit, checkbox, Edit, Copy and Delete features are not available

This is how you get rid of that notice and be able to open those grid cells for edit

1) click "STRUCTURE"

2) go to the field you want to be a primary key (and this usually is the 1st one ) and then click on the "PRIMARY" and "INDEX" fields for that field and accept the PHPMyadmin's pop-up question "OK".

3) pad yourself in the back.

Chrome extension: accessing localStorage in content script

Another option would be to use the chromestorage API. This allows storage of user data with optional syncing across sessions.

One downside is that it is asynchronous.

The entity type <type> is not part of the model for the current context

Sounds obvious, but make sure that you are not explicitly ignoring the type:


Open Facebook page from Android app?

You can open the facebook app on button click as follows:-

protected void onCreate(Bundle savedInstanceState) {

    this.findViewById( View.OnClickListener() {

        public void onClick(View v) {



public void startNewActivity( String packageName)
    Intent intent = MainActivity.this.getPackageManager().getLaunchIntentForPackage(packageName);
    if (intent != null)
        // we found the activity
        // now start the activity
        // bring user to the market
        // or let them choose an app?
        intent = new Intent(Intent.ACTION_VIEW);

Select From all tables - MySQL

why you dont just dump the mysql database but with extension when you run without --single-transaction you will interrupt the connection to other clients:

mysqldump --port=0000 --user=username --password=password --single-transaction --skip-add-locks --skip-lock-tables --default-character-set=utf8 datenbankname > mysqlDBBackup.sql 

after that read out the file and search for what you want.... in Strings.....

Error: Cannot match any routes. URL Segment: - Angular 2

please modify your router.module.ts as:

const routes: Routes = [
    path: '',
    redirectTo: 'one',
    pathMatch: 'full'
    path: 'two',
    component: ClassTwo, children: [
            path: 'three',
            component: ClassThree,
            outlet: 'nameThree',
            path: 'four',
            component: ClassFour,
            outlet: 'nameFour'
           path: '',
           redirectTo: 'two',
           pathMatch: 'full'

and in your component1.html

<h3>In One</h3>

    <a routerLink="/two" class="dash-item">...Go to Two...</a>
    <a routerLink="/two/three" class="dash-item">... Go to THREE...</a>
    <a routerLink="/two/four" class="dash-item">...Go to FOUR...</a>

<router-outlet></router-outlet>                   // Successfully loaded component2.html
<router-outlet name="nameThree" ></router-outlet> // Error: Cannot match any routes. URL Segment: 'three'
<router-outlet name="nameFour" ></router-outlet>  // Error: Cannot match any routes. URL Segment: 'three'

django import error - No module named

Agreed completely that this is a path issue but fwiw, I had this same error. It was due to the mistake of using a relative path for my Python executable when setting up my virtual environment. I had done this:

virtualenv -p ~/python_runtimes/2.7.3/bin/python venv2.7.3 --distribute

Instead I had to give the full path to the Python executable.

HTH, Harlin

How to condense if/else into one line in Python?

Only for using as a value:

x = 3 if a==2 else 0


return 3 if a==2 else 0

List<String> to ArrayList<String> conversion issue

Tried and tested approach.

public static ArrayList<String> listToArrayList(List<Object> myList) {
        ArrayList<String> arl = new ArrayList<String>();
        for (Object object : myList) {
            arl.add((String) object);
        return arl;


Automatically open default email client and pre-populate content

Try this: It will open the default mail directly.

<a href="mailto:[email protected]"><img src="ICON2.png"></a>

if else statement in AngularJS templates

In this case you want to "calculate" a pixel value depending of an object property.

I would define a function in the controller that calculates the pixel values.

In the controller:

$scope.GetHeight = function(aspect) {
   if(bla bla bla) return 270;
   return 360;

Then in your template you just write:

element height="{{ GetHeight(aspect) }}px "

maxReceivedMessageSize and maxBufferSize in app.config

You can do that in your app.config. like that:


(The max value is Int32.MaxValue )

Or in Code:

WSHttpBinding binding = new WSHttpBinding();
binding.Name = "MyBinding";
binding.MaxReceivedMessageSize = Int32.MaxValue;


If your service is open to the Wide world, think about security when you increase this value.

Building a fat jar using maven

Note: If you are a spring-boot application, read the end of answer

Add following plugin to your pom.xml The latest version can be found at

            <version>CHOOSE LATEST VERSION HERE</version>

After configuring this plug-in, running mvn package will produce two jars: one containing just the project classes, and a second fat jar with all dependencies with the suffix "-jar-with-dependencies".

if you want correct classpath setup at runtime then also add following plugin


For spring boot application use just following plugin (choose appropriate version of it)


JUnit test for System.out.println()

You can set the System.out print stream via setOut() (and for in and err). Can you redirect this to a print stream that records to a string, and then inspect that ? That would appear to be the simplest mechanism.

(I would advocate, at some stage, convert the app to some logging framework - but I suspect you already are aware of this!)

Writing Unicode text to a text file?

Deal exclusively with unicode objects as much as possible by decoding things to unicode objects when you first get them and encoding them as necessary on the way out.

If your string is actually a unicode object, you'll need to convert it to a unicode-encoded string object before writing it to a file:

foo = u'?, ?, ?, ? ?, ?, ?, ?, ?, and ?.'
f = open('test', 'w')

When you read that file again, you'll get a unicode-encoded string that you can decode to a unicode object:

f = file('test', 'r')