Programs & Examples On #Auto registration

How do I drop a foreign key constraint only if it exists in sql server?

This is a lot simpler than the current proposed solution:

IF (OBJECT_ID('dbo.FK_ConstraintName', 'F') IS NOT NULL)
BEGIN
    ALTER TABLE dbo.TableName DROP CONSTRAINT FK_ConstraintName
END

If you need to drop another type of constraint, these are the applicable codes to pass into the OBJECT_ID() function in the second parameter position:

C = CHECK constraint
D = DEFAULT (constraint or stand-alone)
F = FOREIGN KEY constraint
PK = PRIMARY KEY constraint
UQ = UNIQUE constraint

You can also use OBJECT_ID without the second parameter.

Full List of types here:

Object type:

AF = Aggregate function (CLR)
C = CHECK constraint
D = DEFAULT (constraint or stand-alone)
F = FOREIGN KEY constraint
FN = SQL scalar function
FS = Assembly (CLR) scalar-function
FT = Assembly (CLR) table-valued function
IF = SQL inline table-valued function
IT = Internal table
P = SQL Stored Procedure
PC = Assembly (CLR) stored-procedure
PG = Plan guide
PK = PRIMARY KEY constraint
R = Rule (old-style, stand-alone)
RF = Replication-filter-procedure
S = System base table
SN = Synonym
SO = Sequence object

Applies to: SQL Server 2012 through SQL Server 2014.

SQ = Service queue
TA = Assembly (CLR) DML trigger
TF = SQL table-valued-function
TR = SQL DML trigger
TT = Table type
U = Table (user-defined)
UQ = UNIQUE constraint
V = View
X = Extended stored procedure

What is the difference between window, screen, and document in Javascript?

The window is the first thing that gets loaded into the browser. This window object has the majority of the properties like length, innerWidth, innerHeight, name, if it has been closed, its parents, and more.

The document object is your html, aspx, php, or other document that will be loaded into the browser. The document actually gets loaded inside the window object and has properties available to it like title, URL, cookie, etc. What does this really mean? That means if you want to access a property for the window it is window.property, if it is document it is window.document.property which is also available in short as document.property.

How to auto-remove trailing whitespace in Eclipse?

I assume your questions is with regards to Java code. If that's the case, you don't actually need any extra plugins to accomplish 1). You can just go to Preferences -> Java -> Editor -> Save Actions and configure it to remove trailing whitespace.

By the sounds of it you also want to make this a team-wide setting, right? To make life easier and avoid having to remember setting it up every time you have a new workspace you can set the save action as a project specific preference that gets stored into your SCM along with the code.

In order to do that right-click on your project and go to Properties -> Java Editor -> Save Actions. From there you can enable project specific settings and configure it to remove trailing whitespace (among other useful things).

NB: This option has been removed in Eclipse Kepler (4.3) and following releases.

NB #2: The option seems to be back in Eclipse Luna - Luna Service Release 1a (4.4.1)

Create 3D array using Python

You should use a list comprehension:

>>> import pprint
>>> n = 3
>>> distance = [[[0 for k in xrange(n)] for j in xrange(n)] for i in xrange(n)]
>>> pprint.pprint(distance)
[[[0, 0, 0], [0, 0, 0], [0, 0, 0]],
 [[0, 0, 0], [0, 0, 0], [0, 0, 0]],
 [[0, 0, 0], [0, 0, 0], [0, 0, 0]]]
>>> distance[0][1]
[0, 0, 0]
>>> distance[0][1][2]
0

You could have produced a data structure with a statement that looked like the one you tried, but it would have had side effects since the inner lists are copy-by-reference:

>>> distance=[[[0]*n]*n]*n
>>> pprint.pprint(distance)
[[[0, 0, 0], [0, 0, 0], [0, 0, 0]],
 [[0, 0, 0], [0, 0, 0], [0, 0, 0]],
 [[0, 0, 0], [0, 0, 0], [0, 0, 0]]]
>>> distance[0][0][0] = 1
>>> pprint.pprint(distance)
[[[1, 0, 0], [1, 0, 0], [1, 0, 0]],
 [[1, 0, 0], [1, 0, 0], [1, 0, 0]],
 [[1, 0, 0], [1, 0, 0], [1, 0, 0]]]

How to display div after click the button in Javascript?

HTML

<div id="myDiv" style="display:none;" class="answer_list" >WELCOME</div>
<input type="button" name="answer" onclick="ShowDiv()" />

JavaScript

function ShowDiv() {
    document.getElementById("myDiv").style.display = "";
}

Or if you wanted to use jQuery with a nice little animation:

<input id="myButton" type="button" name="answer" />

$('#myButton').click(function() {
  $('#myDiv').toggle('slow', function() {
    // Animation complete.
  });
});

How can I start InternetExplorerDriver using Selenium WebDriver

1---Enable protected mode for all zones You need to enable protected mode for all zones from Internet Options -> Security tab. To enable protected mode for all zones

Open Internet Explorer browser.
Go to menu Tools -> Internet Options.
Click on Security tab.
Select Internet from "Select a zone to view or change security settings" and Select(check) check box "Enable Protected Mode" from In the "Security level for this zone" block .
Apply same thing for all other 3 zones -> Local Internet, Trusted Sites and Restricted Sites

This setting will resolve error related to "Protected Mode settings are not the same for all zones.

2-- Set IE browser's zoom level 100%

Open Internet Explorer browser.
Go to menu View -> Zoom -> Select 100%

Checking Value of Radio Button Group via JavaScript?

Use document.querySelector() if you want to avoid frameworks (which I almost always want to do).

document.querySelector('input[name="gender"]:checked').value

Easier way to create circle div than using an image?

Here's a demo: http://jsfiddle.net/thirtydot/JJytE/1170/

CSS:

.circleBase {
    border-radius: 50%;
    behavior: url(PIE.htc); /* remove if you don't care about IE8 */
}

.type1 {
    width: 100px;
    height: 100px;
    background: yellow;
    border: 3px solid red;
}
.type2 {
    width: 50px;
    height: 50px;
    background: #ccc;
    border: 3px solid #000;
}
.type3 {
    width: 500px;
    height: 500px;
    background: aqua;
    border: 30px solid blue;
}

HTML:

<div class="circleBase type1"></div>

<div class="circleBase type2"></div><div class="circleBase type2"></div>

<div class="circleBase type3"></div>

To make this work in IE8 and older, you must download and use CSS3 PIE. My demo above won't work in IE8, but that's only because jsFiddle doesn't host PIE.htc.

My demo looks like this:

How to position one element relative to another with jQuery?

NOTE: This requires jQuery UI (not just jQuery).

You can now use:

$("#my_div").position({
    my:        "left top",
    at:        "left bottom",
    of:        this, // or $("#otherdiv")
    collision: "fit"
});

For fast positioning (jQuery UI/Position).

You can download jQuery UI here.

<code> vs <pre> vs <samp> for inline and block code snippets

Consider TextArea

People finding this via Google and looking for a better way to manage the display of their snippets should also consider <textarea> which gives a lot of control over width/height, scrolling etc. Noting that @vsync mentioned the deprecated tag <xmp>, I find <textarea readonly> is an excellent substitute for displaying HTML without the need to escape anything inside it (except where </textarea> might appear within).

For example, to display a single line with controlled line wrapping, consider <textarea rows=1 cols=100 readonly> your html or etc with any characters including tabs and CrLf's </textarea>.

_x000D_
_x000D_
<textarea rows=5 cols=100 readonly>Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>displayed</b>._x000D_
    However, note that &amp; still acts as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;_x000D_
</textarea>
_x000D_
_x000D_
_x000D_

To compare all...

_x000D_
_x000D_
<h2>Compared: TEXTAREA, XMP, PRE, SAMP, CODE</h2>_x000D_
<p>Note that CSS can be used to override default fixed space fonts in each or all these.</p>_x000D_
    _x000D_
    _x000D_
<textarea rows=5 cols=100 readonly>TEXTAREA: Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>displayed natively</b>._x000D_
    However, note that &amp; still acts as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;</textarea>_x000D_
_x000D_
<xmp>XMP: Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>displayed natively</b>._x000D_
    However, note that &amp; (&) will not act as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;_x000D_
</xmp>_x000D_
_x000D_
<pre>PRE: Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>are interpreted, not displayed</b>._x000D_
    However, note that &amp; still acts as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;_x000D_
</pre>_x000D_
_x000D_
<samp>SAMP: Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>are interpreted, not displayed</b>._x000D_
    However, note that &amp; still acts as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;_x000D_
</samp>_x000D_
_x000D_
<code>CODE: Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>are interpreted, not displayed</b>._x000D_
    However, note that &amp; still acts as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;_x000D_
</code>
_x000D_
_x000D_
_x000D_

How can I convert this foreach code to Parallel.ForEach?

These lines Worked for me.

string[] lines = File.ReadAllLines(txtProxyListPath.Text);
var options = new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount * 10 };
Parallel.ForEach(lines , options, (item) =>
{
 //My Stuff
});

Open source PDF library for C/C++ application?

It depends a bit on your needs. Some toolkits are better at drawing, others are better for writing text. Cairo has a pretty good for drawing (it support a wide range of screen and file types, including pdf), but it may not be ideal for good typography.

installing urllib in Python3.6

This happens because your local module named urllib.py shadows the installed requests module you are trying to use. The current directory is preapended to sys.path, so the local name takes precedence over the installed name.

An extra debugging tip when this comes up is to look at the Traceback carefully, and realize that the name of your script in question is matching the module you are trying to import.

Rename your file to something else like url.py. Then It is working fine. Hope it helps!

How to center horizontal table-cell

Just add this class in your css

.column p{
   text-align:center;
}

How do I hide an element when printing a web page?

In your stylesheet add:

@media print
{    
    .no-print, .no-print *
    {
        display: none !important;
    }
}

Then add class='no-print' (or add the no-print class to an existing class statement) in your HTML that you don't want to appear in the printed version, such as your button.

How to fix committing to the wrong Git branch?

To elaborate on this answer, in case you have multiple commits to move from, e.g. develop to new_branch:

git checkout develop # You're probably there already
git reflog # Find LAST_GOOD, FIRST_NEW, LAST_NEW hashes
git checkout new_branch
git cherry-pick FIRST_NEW^..LAST_NEW # ^.. includes FIRST_NEW
git reflog # Confirm that your commits are safely home in their new branch!
git checkout develop
git reset --hard LAST_GOOD # develop is now back where it started

Creating and writing lines to a file

' Create The Object
Set FSO = CreateObject("Scripting.FileSystemObject")

' How To Write To A File
Set File = FSO.CreateTextFile("C:\foo\bar.txt",True)
File.Write "Example String"
File.Close

' How To Read From A File
Set File = FSO.OpenTextFile("C:\foo\bar.txt")
Do Until File.AtEndOfStream
    Line = File.ReadLine
    WScript.Echo(Line)
Loop
File.Close

' Another Method For Reading From A File
Set File = FSO.OpenTextFile("C:\foo\bar.txt")
Set Text = File.ReadAll
WScript.Echo(Text)
File.Close

Saving ssh key fails

On Windows 8.1 using CMDER, I created the ssh key with this file path /c/Users/youruser/.ssh/id_rsa_whatever, the problem was the : that I was using. With this path I didn't create the folder before running the command, there is no need to run mkdir because the command will create the folder automatically.

How does Java resolve a relative path in new File()?

Relative paths can be best understood if you know how Java runs the program.

There is a concept of working directory when running programs in Java. Assuming you have a class, say, FileHelper that does the IO under /User/home/Desktop/projectRoot/src/topLevelPackage/.

Depending on the case where you invoke java to run the program, you will have different working directory. If you run your program from within and IDE, it will most probably be projectRoot.

  • In this case $ projectRoot/src : java topLevelPackage.FileHelper it will be src.

  • In this case $ projectRoot : java -cp src topLevelPackage.FileHelper it will be projectRoot.

  • In this case $ /User/home/Desktop : java -cp ./projectRoot/src topLevelPackage.FileHelper it will be Desktop.

(Assuming $ is your command prompt with standard Unix-like FileSystem. Similar correspondence/parallels with Windows system)

So, your relative path root (.) resolves to your working directory. Thus to be better sure of where to write files, it's said to consider below approach.

package topLevelPackage

import java.io.File;
import java.nio.file.Path;
import java.nio.file.Paths;

public class FileHelper {

    // Not full implementation, just barebone stub for path
    public void createLocalFile() {

        // Explicitly get hold of working directory
        String workingDir = System.getProperty("user.dir");

        Path filePath = Paths.get(workingDir+File.separator+"sampleFile.txt");

        // In case we need specific path, traverse that path, rather using . or .. 
        Path pathToProjectRoot = Paths.get(System.getProperty("user.home"), "Desktop", "projectRoot");

        System.out.println(filePath);
        System.out.println(pathToProjectRoot);

    }
}

Hope this helps.

find vs find_by vs where

There is a difference between find and find_by in that find will return an error if not found, whereas find_by will return null.

Sometimes it is easier to read if you have a method like find_by email: "haha", as opposed to .where(email: some_params).first.

Angular 2 Scroll to top on Route Change

In addition to the perfect answer provided by @Guilherme Meireles as shown below, you could tweak your implementation by adding smooth scroll as shown below

 import { Component, OnInit } from '@angular/core';
    import { Router, NavigationEnd } from '@angular/router';

    @Component({
        selector: 'my-app',
        template: '<ng-content></ng-content>',
    })
    export class MyAppComponent implements OnInit {
        constructor(private router: Router) { }

        ngOnInit() {
            this.router.events.subscribe((evt) => {
                if (!(evt instanceof NavigationEnd)) {
                    return;
                }
                window.scrollTo(0, 0)
            });
        }
    }

then add the snippet below

 html {
      scroll-behavior: smooth;
    }

to your styles.css

In Javascript/jQuery what does (e) mean?

The e argument is short for the event object. For example, you might want to create code for anchors that cancels the default action. To do this you would write something like:

$('a').click(function(e) {
    e.preventDefault();
}

This means when an <a> tag is clicked, prevent the default action of the click event.

While you may see it often, it's not something you have to use within the function even though you have specified it as an argument.

Python - IOError: [Errno 13] Permission denied:

Just Close the opened file where you are going to write.

Checking if a double (or float) is NaN in C++

There is an std::isnan if you compiler supports c99 extensions, but I'm not sure if mingw does.

Here is a small function which should work if your compiler doesn't have the standard function:

bool custom_isnan(double var)
{
    volatile double d = var;
    return d != d;
}

What's the difference between Invoke() and BeginInvoke()

Just adding why and when to use Invoke().

Both Invoke() and BeginInvoke() marshal the code you specify to the dispatcher thread.

But unlike BeginInvoke(), Invoke() stalls your thread until the dispatcher executes your code. You might want to use Invoke() if you need to pause an asynchronous operation until the user has supplied some sort of feedback.

For example, you could call Invoke() to run a snippet of code that shows an OK/Cancel dialog box. After the user clicks a button and your marshaled code completes, the invoke() method will return, and you can act upon the user's response.

See Pro WPF in C# chapter 31

iCheck check if checkbox is checked

Use following code to check if iCheck is checked or not using single method.

$('Selector').on('ifChanged', function(event){

    //Check if checkbox is checked or not
    var checkboxChecked = $(this).is(':checked');

    if(checkboxChecked) {
        alert("checked");
    }else{
        alert("un-checked");
    }
});

Can HTML be embedded inside PHP "if" statement?

<?php if ($my_name == 'aboutme') { ?>
    HTML_GOES_HERE
<?php } ?>

Height equal to dynamic width (CSS fluid layout)

There is a way using CSS!

If you set your width depending on the parent container you can set the height to 0 and set padding-bottom to the percentage which will be calculated depending on the current width:

.some_element {
    position: relative;
    width: 20%;
    height: 0;
    padding-bottom: 20%;
}

This works well in all major browsers.

JSFiddle: https://jsfiddle.net/ayb9nzj3/

How to check if input date is equal to today's date?

for completeness, taken from this solution:

You could use toDateString:

var today = new Date();
var isToday = (today.toDateString() == otherDate.toDateString());

no library dependencies, and looking cleaner than the 'setHours()' approach shown in a previous answer, imho

Web API optional parameters

Sku is an int, can't be defaulted to string "sku". Please check Optional URI Parameters and Default Values

Vue.js img src concatenate variable and text

If it helps, I am using the following to get a gravatar image:

<img
        :src="`https://www.gravatar.com/avatar/${this.gravatarHash(email)}?s=${size}&d=${this.defaultAvatar(email)}`"
        class="rounded-circle"
        :width="size"
    />

Test if a string contains a word in PHP?

<?php
//  Use this function and Pass Mixed string and what you want to search in mixed string.
//  For Example :
    $mixedStr = "hello world. This is john duvey";
    $searchStr= "john";

    if(strpos($mixedStr,$searchStr)) {
      echo "Your string here";
    }else {
      echo "String not here";
    }

Setting Windows PATH for Postgres tools

On Postgres 9.6(PgAdmin 4) , this can be set up in Preferences->Paths->Binary paths: - set PostgreSQL Binary Path variable to "C:\Program Files\PostgreSQL\9.6\bin" or where you have installed

Iterate Multi-Dimensional Array with Nested Foreach Statement

Use LINQ .Cast<int>() to convert 2D array to IEnumerable<int>.

LINQPad example:

var arr = new int[,] { 
  { 1, 2, 3 }, 
  { 4, 5, 6 } 
};

IEnumerable<int> values = arr.Cast<int>();
Console.WriteLine(values);

Output:

Sequence is 1,2,3,4,5,6

How to stop a vb script running in windows

I can think of at least 2 different ways:

  1. using Task Manager (Ctrl-Shift-Esc), select the process tab, look for a process name cscript.exe or wscript.exe and use End Process.

  2. From the command line you could use taskkill /fi "imagename eq cscript.exe" (change to wscript.exe as needed)

Another way is using scripting and WMI. Here are some hints: look for the Win32_Process class and the Terminate method.

What is in your .vimrc?

I show fold contents and syntax groups on mouse-over:

function! SyntaxBallon()
    let synID   = synID(v:beval_lnum, v:beval_col, 0)
    let groupID = synIDtrans(synID)
    let name    = synIDattr(synID, "name")
    let group   = synIDattr(groupID, "name")
    return name . "\n" . group
endfunction

function! FoldBalloon()
    let foldStart = foldclosed(v:beval_lnum)
    let foldEnd   = foldclosedend(v:beval_lnum)
    let lines = []
    if foldStart >= 0
        " we are in a fold
        let numLines = foldEnd - foldStart + 1
        if (numLines > 17)
            " show only the first 8 and the last 8 lines
            let lines += getline(foldStart, foldStart + 8)
            let lines += [ '-- Snipped ' . (numLines - 16) . ' lines --']
            let lines += getline(foldEnd - 8, foldEnd)
        else
            " show all lines
            let lines += getline(foldStart, foldEnd)
        endif
    endif
    " return result
    return join(lines, has("balloon_multiline") ? "\n" : " ")
endfunction

function! Balloon()
    if foldclosed(v:beval_lnum) >= 0
        return FoldBalloon()
    else
        return SyntaxBallon()
endfunction

set balloonexpr=Balloon()
set ballooneval

Check for a substring in a string in Oracle without LIKE

I'm guessing the reason you're asking is performance? There's the instr function. But that's likely to work pretty much the same behind the scenes.

Maybe you could look into full text search.

As last resorts you'd be looking at caching or precomputed columns/an indexed view.

How to detect current state within directive

If you are using ui-router, try $state.is();

You can use it like so:

$state.is('stateName');

Per the documentation:

$state.is ... similar to $state.includes, but only checks for the full state name.

How to implement a tree data-structure in Java?

You should start by defining what a tree is (for the domain), this is best done by defining the interface first. Not all trees structures are modifyable, being able to add and remove nodes should be an optional feature, so we make an extra interface for that.

There's no need to create node objects which hold the values, in fact I see this as a major design flaw and overhead in most tree implementations. If you look at Swing, the TreeModel is free of node classes (only DefaultTreeModel makes use of TreeNode), as they are not really needed.

public interface Tree <N extends Serializable> extends Serializable {
    List<N> getRoots ();
    N getParent (N node);
    List<N> getChildren (N node);
}

Mutable tree structure (allows to add and remove nodes):

public interface MutableTree <N extends Serializable> extends Tree<N> {
    boolean add (N parent, N node);
    boolean remove (N node, boolean cascade);
}

Given these interfaces, code that uses trees doesn't have to care much about how the tree is implemented. This allows you to use generic implementations as well as specialized ones, where you realize the tree by delegating functions to another API.

Example: file tree structure

public class FileTree implements Tree<File> {

    @Override
    public List<File> getRoots() {
        return Arrays.stream(File.listRoots()).collect(Collectors.toList());
    }

    @Override
    public File getParent(File node) {
        return node.getParentFile();
    }

    @Override
    public List<File> getChildren(File node) {
        if (node.isDirectory()) {
            File[] children = node.listFiles();
            if (children != null) {
                return Arrays.stream(children).collect(Collectors.toList());
            }
        }
        return Collections.emptyList();
    }
}

Example: generic tree structure (based on parent/child relations):

public class MappedTreeStructure<N extends Serializable> implements MutableTree<N> {

    public static void main(String[] args) {

        MutableTree<String> tree = new MappedTreeStructure<>();
        tree.add("A", "B");
        tree.add("A", "C");
        tree.add("C", "D");
        tree.add("E", "A");
        System.out.println(tree);
    }

    private final Map<N, N> nodeParent = new HashMap<>();
    private final LinkedHashSet<N> nodeList = new LinkedHashSet<>();

    private void checkNotNull(N node, String parameterName) {
        if (node == null)
            throw new IllegalArgumentException(parameterName + " must not be null");
    }

    @Override
    public boolean add(N parent, N node) {
        checkNotNull(parent, "parent");
        checkNotNull(node, "node");

        // check for cycles
        N current = parent;
        do {
            if (node.equals(current)) {
                throw new IllegalArgumentException(" node must not be the same or an ancestor of the parent");
            }
        } while ((current = getParent(current)) != null);

        boolean added = nodeList.add(node);
        nodeList.add(parent);
        nodeParent.put(node, parent);
        return added;
    }

    @Override
    public boolean remove(N node, boolean cascade) {
        checkNotNull(node, "node");

        if (!nodeList.contains(node)) {
            return false;
        }
        if (cascade) {
            for (N child : getChildren(node)) {
                remove(child, true);
            }
        } else {
            for (N child : getChildren(node)) {
                nodeParent.remove(child);
            }
        }
        nodeList.remove(node);
        return true;
    }

    @Override
    public List<N> getRoots() {
        return getChildren(null);
    }

    @Override
    public N getParent(N node) {
        checkNotNull(node, "node");
        return nodeParent.get(node);
    }

    @Override
    public List<N> getChildren(N node) {
        List<N> children = new LinkedList<>();
        for (N n : nodeList) {
            N parent = nodeParent.get(n);
            if (node == null && parent == null) {
                children.add(n);
            } else if (node != null && parent != null && parent.equals(node)) {
                children.add(n);
            }
        }
        return children;
    }

    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        dumpNodeStructure(builder, null, "- ");
        return builder.toString();
    }

    private void dumpNodeStructure(StringBuilder builder, N node, String prefix) {
        if (node != null) {
            builder.append(prefix);
            builder.append(node.toString());
            builder.append('\n');
            prefix = "  " + prefix;
        }
        for (N child : getChildren(node)) {
            dumpNodeStructure(builder, child, prefix);
        }
    }
}

Correct way of looping through C++ arrays

In C/C++ sizeof. always gives the number of bytes in the entire object, and arrays are treated as one object. Note: sizeof a pointer--to the first element of an array or to a single object--gives the size of the pointer, not the object(s) pointed to. Either way, sizeof does not give the number of elements in the array (its length). To get the length, you need to divide by the size of each element. eg.,

for( unsigned int a = 0; a < sizeof(texts)/sizeof(texts[0]); a = a + 1 )

As for doing it the C++11 way, the best way to do it is probably

for(const string &text : texts)
    cout << "value of text: " << text << endl;

This lets the compiler figure out how many iterations you need.

EDIT: as others have pointed out, std::array is preferred in C++11 over raw arrays; however, none of the other answers addressed why sizeof is failing the way it is, so I still think this is the better answer.

What is the default lifetime of a session?

The default in the php.ini for the session.gc_maxlifetime directive (the "gc" is for garbage collection) is 1440 seconds or 24 minutes. See the Session Runtime Configuation page in the manual:

http://www.php.net/manual/en/session.configuration.php

You can change this constant in the php.ini or .httpd.conf files if you have access to them, or in the local .htaccess file on your web site. To set the timeout to one hour using the .htaccess method, add this line to the .htaccess file in the root directory of the site:

php_value session.gc_maxlifetime "3600"

Be careful if you are on a shared host or if you host more than one site where you have not changed the default. The default session location is the /tmp directory, and the garbage collection routine will run every 24 minutes for these other sites (and wipe out your sessions in the process, regardless of how long they should be kept). See the note on the manual page or this site for a better explanation.

The answer to this is to move your sessions to another directory using session.save_path. This also helps prevent bad guys from hijacking your visitors' sessions from the default /tmp directory.

ClientScript.RegisterClientScriptBlock?

See if the below helps you:

I was using the following earlier:

ClientScript.RegisterClientScriptBlock(Page.GetType(), "AlertMsg", "<script language='javascript'>alert('The Web Policy need to be accepted to submit the new assessor information.');</script>");

After implementing AJAX in this page, it stopped working. After reading your blog, I changed the above to:

ScriptManager.RegisterClientScriptBlock(imgBtnSubmit, this.GetType(), "AlertMsg", "<script language='javascript'>alert('The Web Policy need to be accepted to submit the new assessor information.');</script>", false);

This is working perfectly fine.

(It’s .NET 2.0 Framework, I am using)

The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHA256

You should set signatureVersion: 'v4' in config to use new sign version:

AWS.config.update({
    signatureVersion: 'v4'
});

Works for JS sdk.

Simple regular expression for a decimal with a precision of 2

Won't you need to take the e in e666.76 into account?

With

(e|0-9)\d*\d.\d{1,2)

How to create Windows EventLog source from command line?

Try "eventcreate.exe"

An example:

eventcreate /ID 1 /L APPLICATION /T INFORMATION  /SO MYEVENTSOURCE /D "My first log"

This will create a new event source named MYEVENTSOURCE under APPLICATION event log as INFORMATION event type.

I think this utility is included only from XP onwards.

Further reading

Returning a boolean value in a JavaScript function

An old thread, sure, but a popular one apparently. It's 2020 now and none of these answers have addressed the issue of unreadable code. @pimvdb's answer takes up less lines, but it's also pretty complicated to follow. For easier debugging and better readability, I should suggest refactoring the OP's code to something like this, and adopting an early return pattern, as this is likely the main reason you were unsure of why the were getting undefined:

function validatePassword() {
   const password = document.getElementById("password");
   const confirm_password = document.getElementById("password_confirm");

   if (password.value.length === 0) {
      return false;
   }

   if (password.value !== confirm_password.value) {
      return false;
   }
  
   return true;
}

How to print a two dimensional array?

I am also a beginner and I've just managed to crack this using two nested for loops.

I looked at the answers here and tbh they're a bit advanced for me so I thought I'd share mine to help all the other newbies out there.

P.S. It's for a Whack-A-Mole game hence why the array is called 'moleGrid'.

public static void printGrid() {
    for (int i = 0; i < moleGrid.length; i++) {
        for (int j = 0; j < moleGrid[0].length; j++) {
            if (j == 0 || j % (moleGrid.length - 1) != 0) {
                System.out.print(moleGrid[i][j]);
            }
            else {
                System.out.println(moleGrid[i][j]);
            }
         }
     }
}

Hope it helps!

Random String Generator Returning Same String

I added the option to choose the length using the Ranvir solution

public static string GenerateRandomString(int length)
    {
        {
            string randomString= string.Empty;

            while (randomString.Length <= length)
            {
                randomString+= Path.GetRandomFileName();
                randomString= randomString.Replace(".", string.Empty);
            }

            return randomString.Substring(0, length);
        }
    }

@try - catch block in Objective-C

Objective-C is not Java. In Objective-C exceptions are what they are called. Exceptions! Don’t use them for error handling. It’s not their proposal. Just check the length of the string before using characterAtIndex and everything is fine....

Best Practices for mapping one object to another

I would opt for AutoMapper, an open source and free mapping library which allows to map one type into another, based on conventions (i.e. map public properties with the same names and same/derived/convertible types, along with many other smart ones). Very easy to use, will let you achieve something like this:

Model model = Mapper.Map<Model>(dto);

Not sure about your specific requirements, but AutoMapper also supports custom value resolvers, which should help you writing a single, generic implementation of your particular mapper.

Enter export password to generate a P12 certificate

MacOS High Sierra is very crazy to update openssl command suddenly.

Possible in last month:

$ openssl pkcs12 -in cert.p12 -out cert.pem -nodes -clcerts
MAC verified OK

But now:

$ openssl pkcs12 -in cert.p12 -out cert.pem -nodes -clcerts -password pass:
MAC verified OK

Adding a css class to select using @Html.DropDownList()

Try this:

@Html.DropDownList(
    "country", 
    new[] {
        new SelectListItem() { Value = "IN", Text = "India" },
        new SelectListItem() { Value = "US", Text = "United States" }
    }, 
    "Country",
    new { @class = "form-control",@selected = Model.Country}
)

Change an image with onclick()

If you don't want use js, I think, you can use <a href="javascript:void(0);"></a> instead of img and then use css like

a {
  background: url('oldImage.png');
}
a:visited {
  background: url('newImage.png');
}

EDIT: Nope. Sorry it works only for :hover

OpenCV Python rotate image by X degrees around specific point

def rotate(image, angle, center = None, scale = 1.0):
    (h, w) = image.shape[:2]

    if center is None:
        center = (w / 2, h / 2)

    # Perform the rotation
    M = cv2.getRotationMatrix2D(center, angle, scale)
    rotated = cv2.warpAffine(image, M, (w, h))

    return rotated

Clearing content of text file using php

//create a file handler by opening the file
$myTextFileHandler = @fopen("filelist.txt","r+");

//truncate the file to zero
//or you could have used the write method and written nothing to it
@ftruncate($myTextFileHandler, 0);

//use location header to go back to index.html
header("Location:index.html");

I don't exactly know where u want to show the result.

Where is jarsigner?

This will install jdk for you and check for the jarsigner inside it

sudo apt install -y default-jdk

to find jarsigner you can use whereis jarsigner

to_string is not a member of std, says g++ (mingw)

to_string is a current issue with Cygwin

Here's a new-ish answer to an old thread. A new one did come up but was quickly quashed, Cygwin: g++ 5.2: ‘to_string’ is not a member of ‘std’.

Too bad, maybe we would have gotten an updated answer. According to @Alex, Cygwin g++ 5.2 is still not working as of November 3, 2015.

On January 16, 2015 Corinna Vinschen, a Cygwin maintainer at Red Hat said the problem was a shortcoming of newlib. It doesn't support most long double functions and is therefore not C99 aware.

Red Hat is,

... still hoping to get the "long double" functionality into newlib at one point.

On October 25, 2015 Corrine also said,

It would still be nice if somebody with a bit of math knowledge would contribute the missing long double functions to newlib.

So there we have it. Maybe one of us who has the knowledge, and the time, can contribute and be the hero.

Newlib is here.

What are the use cases for selecting CHAR over VARCHAR in SQL?

Using CHAR (NCHAR) and VARCHAR (NVARCHAR) brings differences in the ways the database server stores the data. The first one introduces trailing blanks; I have encountered problem when using it with LIKE operator in SQL SERVER functions. So I have to make it safe by using VARCHAR (NVARCHAR) all the times.

For example, if we have a table TEST(ID INT, Status CHAR(1)), and you write a function to list all the records with some specific value like the following:

CREATE FUNCTION List(@Status AS CHAR(1) = '')
RETURNS TABLE
AS
RETURN
SELECT * FROM TEST
WHERE Status LIKE '%' + @Status '%'

In this function we expect that when we put the default parameter the function will return all the rows, but in fact it does not. Change the @Status data type to VARCHAR will fix the issue.

Get fragment (value after hash '#') from a URL in php

You can't get the text after the hash mark. It is not sent to the server in a request.

PHP - Fatal error: Unsupported operand types

I had a similar error with the following code:-

foreach($myvar as $key => $value){
    $query = "SELECT stuff
            FROM table
            WHERE col1 = '$criteria1'
            AND col2 = '$criteria2'";

    $result = mysql_query($query) or die('Could not execute query - '.mysql_error(). __FILE__. __LINE__. $query);               
    $point_values = mysql_fetch_assoc($result);
    $top_five_actions[$key] += $point_values; //<--- Problem Line       
}

It turned out that my $point_values variable was occasionally returning false which caused the problem so I fixed it by wrapping it in mysql_num_rows check:-

if(mysql_num_rows($result) > 0) {
        $point_values = mysql_fetch_assoc($result);
        $top_five_actions[$key] += $point_values;
}

Not sure if this helps though?

Cheers

How do you generate dynamic (parameterized) unit tests in Python?

Following is my solution. I find this useful when:

  1. Should work for unittest.Testcase and unittest discover

  2. Have a set of tests to be run for different parameter settings.

  3. Very simple and no dependency on other packages

     import unittest
    
     class BaseClass(unittest.TestCase):
         def setUp(self):
             self.param = 2
             self.base = 2
    
         def test_me(self):
             self.assertGreaterEqual(5, self.param+self.base)
    
         def test_me_too(self):
             self.assertLessEqual(3, self.param+self.base)
    
    
      class Child_One(BaseClass):
         def setUp(self):
             BaseClass.setUp(self)
             self.param = 4
    
    
      class Child_Two(BaseClass):
         def setUp(self):
             BaseClass.setUp(self)
             self.param = 1
    

Text inset for UITextField?

I found the option posted by roberto.buratti the fastest solution, here it is in Swift:

let leftView = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: textField.frame.size.height))
leftView.backgroundColor = textField.backgroundColor
textField.leftView = leftView
textField.leftViewMode = UITextField.ViewMode.always

Automatic date update in a cell when another cell's value changes (as calculated by a formula)

You could fill the dependend cell (D2) by a User Defined Function (VBA Macro Function) that takes the value of the C2-Cell as input parameter, returning the current date as ouput.

Having C2 as input parameter for the UDF in D2 tells Excel that it needs to reevaluate D2 everytime C2 changes (that is if auto-calculation of formulas is turned on for the workbook).

EDIT:

Here is some code:

For the UDF:

    Public Function UDF_Date(ByVal data) As Date

        UDF_Date = Now()

    End Function

As Formula in D2:

=UDF_Date(C2)

You will have to give the D2-Cell a Date-Time Format, or it will show a numeric representation of the date-value.

And you can expand the formula over the desired range by draging it if you keep the C2 reference in the D2-formula relative.

Note: This still might not be the ideal solution because every time Excel recalculates the workbook the date in D2 will be reset to the current value. To make D2 only reflect the last time C2 was changed there would have to be some kind of tracking of the past value(s) of C2. This could for example be implemented in the UDF by providing also the address alonside the value of the input parameter, storing the input parameters in a hidden sheet, and comparing them with the previous values everytime the UDF gets called.

Addendum:

Here is a sample implementation of an UDF that tracks the changes of the cell values and returns the date-time when the last changes was detected. When using it, please be aware that:

  • The usage of the UDF is the same as described above.

  • The UDF works only for single cell input ranges.

  • The cell values are tracked by storing the last value of cell and the date-time when the change was detected in the document properties of the workbook. If the formula is used over large datasets the size of the file might increase considerably as for every cell that is tracked by the formula the storage requirements increase (last value of cell + date of last change.) Also, maybe Excel is not capable of handling very large amounts of document properties and the code might brake at a certain point.

  • If the name of a worksheet is changed all the tracking information of the therein contained cells is lost.

  • The code might brake for cell-values for which conversion to string is non-deterministic.

  • The code below is not tested and should be regarded only as proof of concept. Use it at your own risk.

    Public Function UDF_Date(ByVal inData As Range) As Date
    
        Dim wb As Workbook
        Dim dProps As DocumentProperties
        Dim pValue As DocumentProperty
        Dim pDate As DocumentProperty
        Dim sName As String
        Dim sNameDate As String
    
        Dim bDate As Boolean
        Dim bValue As Boolean
        Dim bChanged As Boolean
    
        bDate = True
        bValue = True
    
        bChanged = False
    
    
        Dim sVal As String
        Dim dDate As Date
    
        sName = inData.Address & "_" & inData.Worksheet.Name
        sNameDate = sName & "_dat"
    
        sVal = CStr(inData.Value)
        dDate = Now()
    
        Set wb = inData.Worksheet.Parent
    
        Set dProps = wb.CustomDocumentProperties
    
    On Error Resume Next
    
        Set pValue = dProps.Item(sName)
    
        If Err.Number <> 0 Then
            bValue = False
            Err.Clear
        End If
    
    On Error GoTo 0
    
        If Not bValue Then
            bChanged = True
            Set pValue = dProps.Add(sName, False, msoPropertyTypeString, sVal)
        Else
            bChanged = pValue.Value <> sVal
            If bChanged Then
                pValue.Value = sVal
            End If
        End If
    
    On Error Resume Next
    
        Set pDate = dProps.Item(sNameDate)
    
        If Err.Number <> 0 Then
            bDate = False
            Err.Clear
        End If
    
    On Error GoTo 0
    
        If Not bDate Then
            Set pDate = dProps.Add(sNameDate, False, msoPropertyTypeDate, dDate)
        End If
    
        If bChanged Then
            pDate.Value = dDate
        Else
            dDate = pDate.Value
        End If
    
    
        UDF_Date = dDate
     End Function
    

Make the insertion of the date conditional upon the range.

This has an advantage of not changing the dates unless the content of the cell is changed, and it is in the range C2:C2, even if the sheet is closed and saved, it doesn't recalculate unless the adjacent cell changes.

Adapted from this tip and @Paul S answer

Private Sub Worksheet_Change(ByVal Target As Range)
 Dim R1 As Range
 Dim R2 As Range
 Dim InRange As Boolean
    Set R1 = Range(Target.Address)
    Set R2 = Range("C2:C20")
    Set InterSectRange = Application.Intersect(R1, R2)

  InRange = Not InterSectRange Is Nothing
     Set InterSectRange = Nothing
   If InRange = True Then
     R1.Offset(0, 1).Value = Now()
   End If
     Set R1 = Nothing
     Set R2 = Nothing
 End Sub

Conversion of System.Array to List

I know two methods:

List<int> myList1 = new List<int>(myArray);

Or,

List<int> myList2 = myArray.ToList();

I'm assuming you know about data types and will change the types as you please.

Get div's offsetTop positions in React

Eugene's answer uses the correct function to get the data, but for posterity I'd like to spell out exactly how to use it in React v0.14+ (according to this answer):

  import ReactDOM from 'react-dom';
  //...
  componentDidMount() {
    var rect = ReactDOM.findDOMNode(this)
      .getBoundingClientRect()
  }

Is working for me perfectly, and I'm using the data to scroll to the top of the new component that just mounted.

What version of Python is on my Mac?

Use below command to see all python installations :

which -a python

How to pass the -D System properties while testing on Eclipse?

This will work for junit. for TestNG use following command

-ea -Dmykey="value" -Dmykey2="value2"

Angularjs dynamic ng-pattern validation

I just ran into this the other day.

What I did, which seems easier than the above, is to set the pattern on a variable on the scope and refer to it in ng-pattern in the view.

When "the checkbox is unchecked" I simply set the regex value to /.*/ on the onChanged callback (if going to unchecked). ng-pattern picks that change up and says "OK, your value is fine". Form is now valid. I would also remove the bad data from the field so you don't have an apparent bad phone # sitting there.

I had additional issues around ng-required, and did the same thing. Worked like a charm.

SQL Query to find the last day of the month

Calculate the last date of the month is quite simple calculation -

1 - Find the total months count till today's date using DATEDIFF function -

Select DATEDIFF(MM,0,GETDATE())

Output - 1374, If getdate() output is "2014-07-23 19:33:46.850"

2 -Increment by 1 into total months count -

Select DATEDIFF(MM,0,GETDATE())+1

Output - 1375, If getdate() output is "2014-07-23 19:33:46.850"

3 - Get the first date of next month -

Select DATEADD(MM,DATEDIFF(MM,0,GETDATE())+1,0)

Output - '2014-08-01 00:00:00.000', If getdate() output is "2014-07-23 19:33:46.850"

4 - Subtract by -1 into the first date of next month, which will return last date of the current month -

Select DATEADD(DD,-1,DATEADD(MM,DATEDIFF(MM,0,GETDATE())+1,0))

Output - '2014-07-31 00:00:00.000', If getdate() output is "2014-07-23 19:33:46.850"

In the same manner of calculation we can achieve the -

  1. Last date of next month
  2. Last date of the previous month and so on.

How to pass multiple parameter to @Directives (@Components) in Angular with TypeScript?

From the Documentation

As with components, you can add as many directive property bindings as you need by stringing them along in the template.

Add an input property to HighlightDirective called defaultColor:

@Input() defaultColor: string;

Markup

<p [myHighlight]="color" defaultColor="violet">
  Highlight me too!
</p>

Angular knows that the defaultColor binding belongs to the HighlightDirective because you made it public with the @Input decorator.

Either way, the @Input decorator tells Angular that this property is public and available for binding by a parent component. Without @Input, Angular refuses to bind to the property.

For your example

With many parameters

Add properties into the Directive class with @Input() decorator

@Directive({
    selector: '[selectable]'
})
export class SelectableDirective{
    private el: HTMLElement;

    @Input('selectable') option:any;   
    @Input('first') f;
    @Input('second') s;

    ...
}

And in the template pass bound properties to your li element

<li *ngFor = 'let opt of currentQuestion.options' 
    [selectable] = 'opt' 
    [first]='YourParameterHere'
    [second]='YourParameterHere'
    (selectedOption) = 'onOptionSelection($event)'>
    {{opt.option}}
</li>

Here on the li element we have a directive with name selectable. In the selectable we have two @Input()'s, f with name first and s with name second. We have applied these two on the li properties with name [first] and [second]. And our directive will find these properties on that li element, which are set for him with @Input() decorator. So selectable, [first] and [second] will be bound to every directive on li, which has property with these names.

With single parameter

@Directive({
    selector: '[selectable]'
})
export class SelectableDirective{
    private el: HTMLElement;

    @Input('selectable') option:any;   
    @Input('params') params;

    ...
}

Markup

<li *ngFor = 'let opt of currentQuestion.options' 
    [selectable] = 'opt' 
    [params]='{firstParam: 1, seconParam: 2, thirdParam: 3}'
    (selectedOption) = 'onOptionSelection($event)'>
    {{opt.option}}
</li>

Pass a variable to a PHP script running from the command line

You can use the following code to both work with the command line and a web browser. Put this code above your PHP code. It creates a $_GET variable for each command line parameter.

In your code you only need to check for $_GET variables then, not worrying about if the script is called from the web browser or command line.

if(isset($argv))
    foreach ($argv as $arg) {
        $e=explode("=",$arg);
        if(count($e)==2)
            $_GET[$e[0]]=$e[1];
        else
            $_GET[$e[0]]=0;
    }

Eclipse does not highlight matching variables

maybe because it not supports code highlights inside scriplets. not sure though.

You can try using one of the eclipse plugin like 'glance search' which works great. Here's a link for that- http://code.google.com/p/eclipse-glance/

UDP vs TCP, how much faster is it?

It is meaningless to talk about TCP or UDP without taking the network condition into account. If the network between the two point have a very high quality, UDP is absolutely faster than TCP, but in some other case such as the GPRS network, TCP may been faster and more reliability than UDP.

How to check user is "logged in"?

I managed to find the correct one. It is below.

bool val1 = System.Web.HttpContext.Current.User.Identity.IsAuthenticated

EDIT

The credit of this edit goes to @Gianpiero Caretti who suggested this in comment.

bool val1 = (System.Web.HttpContext.Current.User != null) && System.Web.HttpContext.Current.User.Identity.IsAuthenticated

How to write LDAP query to test if user is member of a group?

I would add one more thing to Marc's answer: The memberOf attribute can't contain wildcards, so you can't say something like "memberof=CN=SPS*", and expect it to find all groups that start with "SPS".

Get file path of image on Android

To get the path of all images in android I am using following code

public void allImages() 
{
    ContentResolver cr = getContentResolver();
    Cursor cursor;
    Uri allimagessuri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
    String selection = MediaStore.Images.Media._ID + " != 0";

    cursor = cr.query(allsongsuri, STAR, selection, null, null);

    if (cursor != null) {
        if (cursor.moveToFirst()) {
            do {

                String fullpath = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Images.Media.DATA));
                Log.i("Image path ", fullpath + "");


            } while (cursor.moveToNext());
        }
        cursor.close();
    }

}

How to remove leading zeros using C#

This is the code you need:

string strInput = "0001234";
strInput = strInput.TrimStart('0');

Remove decimal values using SQL query

If it's a decimal data type and you know it will never contain decimal places you can consider setting the scale property to 0. For example to decimal(18, 0). This will save you from replacing the ".00" characters and the query will be faster. In such case, don't forget to to check if the "prevent saving option" is disabled (SSMS menu "Tools>Options>Designers>Table and database designer>prevent saving changes that require table re-creation").

Othewise, you of course remove it using SQL query:

select replace(cast([height] as varchar), '.00', '') from table

PHP date yesterday

strtotime(), as in date("F j, Y", strtotime("yesterday"));

jQuery Array of all selected checkboxes (by class)

You can also add underscore.js to your project and will be able to do it in one line:

_.map($("input[name='category_ids[]']:checked"), function(el){return $(el).val()})

Share data between AngularJS controllers

Not sure where I picked up this pattern but for sharing data across controllers and reducing the $rootScope and $scope this works great. It is reminiscent of a data replication where you have publishers and subscribers. Hope it helps.

The Service:

(function(app) {
    "use strict";
    app.factory("sharedDataEventHub", sharedDataEventHub);

    sharedDataEventHub.$inject = ["$rootScope"];

    function sharedDataEventHub($rootScope) {
        var DATA_CHANGE = "DATA_CHANGE_EVENT";
        var service = {
            changeData: changeData,
            onChangeData: onChangeData
        };
        return service;

        function changeData(obj) {
            $rootScope.$broadcast(DATA_CHANGE, obj);
        }

        function onChangeData($scope, handler) {
            $scope.$on(DATA_CHANGE, function(event, obj) {
                handler(obj);
            });
        }
    }
}(app));

The Controller that is getting the new data, which is the Publisher would do something like this..

var someData = yourDataService.getSomeData();

sharedDataEventHub.changeData(someData);

The Controller that is also using this new data, which is called the Subscriber would do something like this...

sharedDataEventHub.onChangeData($scope, function(data) {
    vm.localData.Property1 = data.Property1;
    vm.localData.Property2 = data.Property2;
});

This will work for any scenario. So when the primary controller is initialized and it gets data it would call the changeData method which would then broadcast that out to all the subscribers of that data. This reduces the coupling of our controllers to each other.

HTML CSS Button Positioning

as I expected, yeah, it's because the whole DOM element is being pushed down. You have multiple options. You can put the buttons in separate divs, and float them so that they don't affect each other. the simpler solution is to just set the :active button to position:relative; and use top instead of margin or line-height. example fiddle: http://jsfiddle.net/5CZRP/

How do I get the SQLSRV extension to work with PHP, since MSSQL is deprecated?

Download Microsoft Drivers for PHP for SQL Server. Extract the files and use one of:

File                             Thread Safe         VC Bulid
php_sqlsrv_53_nts_vc6.dll           No                  VC6
php_sqlsrv_53_nts_vc9.dll           No                  VC9
php_sqlsrv_53_ts_vc6.dll            Yes                 VC6
php_sqlsrv_53_ts_vc9.dll            Yes                 VC9

You can see the Thread Safety status in phpinfo().

Add the correct file to your ext directory and the following line to your php.ini:

extension=php_sqlsrv_53_*_vc*.dll

Use the filename of the file you used.

As Gordon already posted this is the new Extension from Microsoft and uses the sqlsrv_* API instead of mssql_*

Update:
On Linux you do not have the requisite drivers and neither the SQLSERV Extension.
Look at Connect to MS SQL Server from PHP on Linux? for a discussion on this.

In short you need to install FreeTDS and YES you need to use mssql_* functions on linux. see update 2

To simplify things in the long run I would recommend creating a wrapper class with requisite functions which use the appropriate API (sqlsrv_* or mssql_*) based on which extension is loaded.

Update 2: You do not need to use mssql_* functions on linux. You can connect to an ms sql server using PDO + ODBC + FreeTDS. On windows, the best performing method to connect is via PDO + ODBC + SQL Native Client since the PDO + SQLSRV driver can be incredibly slow.

How do I read a large csv file with pandas?

You can read in the data as chunks and save each chunk as pickle.

import pandas as pd 
import pickle

in_path = "" #Path where the large file is
out_path = "" #Path to save the pickle files to
chunk_size = 400000 #size of chunks relies on your available memory
separator = "~"

reader = pd.read_csv(in_path,sep=separator,chunksize=chunk_size, 
                    low_memory=False)    


for i, chunk in enumerate(reader):
    out_file = out_path + "/data_{}.pkl".format(i+1)
    with open(out_file, "wb") as f:
        pickle.dump(chunk,f,pickle.HIGHEST_PROTOCOL)

In the next step you read in the pickles and append each pickle to your desired dataframe.

import glob
pickle_path = "" #Same Path as out_path i.e. where the pickle files are

data_p_files=[]
for name in glob.glob(pickle_path + "/data_*.pkl"):
   data_p_files.append(name)


df = pd.DataFrame([])
for i in range(len(data_p_files)):
    df = df.append(pd.read_pickle(data_p_files[i]),ignore_index=True)

How to return JSon object

First of all, there's no such thing as a JSON object. What you've got in your question is a JavaScript object literal (see here for a great discussion on the difference). Here's how you would go about serializing what you've got to JSON though:

I would use an anonymous type filled with your results type:

string json = JsonConvert.SerializeObject(new
{
    results = new List<Result>()
    {
        new Result { id = 1, value = "ABC", info = "ABC" },
        new Result { id = 2, value = "JKL", info = "JKL" }
    }
});

Also, note that the generated JSON has result items with ids of type Number instead of strings. I doubt this will be a problem, but it would be easy enough to change the type of id to string in the C#.

I'd also tweak your results type and get rid of the backing fields:

public class Result
{
    public int id { get ;set; }
    public string value { get; set; }
    public string info { get; set; }
}

Furthermore, classes conventionally are PascalCased and not camelCased.

Here's the generated JSON from the code above:

{
  "results": [
    {
      "id": 1,
      "value": "ABC",
      "info": "ABC"
    },
    {
      "id": 2,
      "value": "JKL",
      "info": "JKL"
    }
  ]
}

Targeting .NET Framework 4.5 via Visual Studio 2010

From another search. Worked for me!

"You can use Visual Studio 2010 and it does support it, provided your OS supports .NET 4.5.

Right click on your solution to add a reference (as you do). When the dialog box shows, select browse, then navigate to the following folder:

C:\Program Files(x86)\Reference Assemblies\Microsoft\Framework\.Net Framework\4.5

You will find it there."

Multiline editing in Visual Studio Code

I am using the latest version of VS code i.e., 1.46.1 (May 2020) in Windows 10. Just press Alt+mouse left click on the lines you want to select. This will let you select multiple lines at once and let you edit them. Also Press Esc to exit from it. This is really helpful if you're coming from sublime text.

How to convert String into Hashmap in java

try this out :)

public static HashMap HashMapFrom(String s){
    HashMap base = new HashMap(); //result
    int dismiss = 0; //dismiss tracker
    StringBuilder tmpVal = new StringBuilder(); //each val holder
    StringBuilder tmpKey = new StringBuilder(); //each key holder

    for (String next:s.split("")){ //each of vale
        if(dismiss==0){ //if not writing value
            if (next.equals("=")) //start writing value
                dismiss=1; //update tracker
            else
                tmpKey.append(next); //writing key
        } else {
            if (next.equals("{")) //if it's value so need to dismiss
                dismiss++;
            else if (next.equals("}")) //value closed so need to focus
                dismiss--;
            else if (next.equals(",") //declaration ends
                    && dismiss==1) {
                //by the way you have to create something to correct the type
                Object ObjVal = object.valueOf(tmpVal.toString()); //correct the type of object
                base.put(tmpKey.toString(),ObjVal);//declaring
                tmpKey = new StringBuilder();
                tmpVal = new StringBuilder();
                dismiss--;
                continue; //next :)
            }
            tmpVal.append(next); //writing value
        }
    }
    Object objVal = object.valueOf(tmpVal.toString()); //same as here
    base.put(tmpKey.toString(), objVal); //leftovers
    return base;
}

examples input : "a=0,b={a=1},c={ew={qw=2}},0=a" output : {0=a,a=0,b={a=1},c={ew={qw=2}}}

Force DOM redraw/refresh on Chrome/Mac

I had a react component list which when scrolled, then opened another page, then when returning back the list was not rendered on Safari iOS until page was scrolled. So this is the fix.

    componentDidMount() {
        setTimeout(() => {
            window.scrollBy(0, 0);
        }, 300);
    }

Split text file into smaller multiple text file using command line

@ECHO OFF
SETLOCAL
SET "sourcedir=U:\sourcedir"
SET /a fcount=100
SET /a llimit=5000
SET /a lcount=%llimit%
FOR /f "usebackqdelims=" %%a IN ("%sourcedir%\q25249516.txt") DO (
 CALL :select
 FOR /f "tokens=1*delims==" %%b IN ('set dfile') DO IF /i "%%b"=="dfile" >>"%%c" ECHO(%%a
)
GOTO :EOF
:select
SET /a lcount+=1
IF %lcount% lss %llimit% GOTO :EOF
SET /a lcount=0
SET /a fcount+=1
SET "dfile=%sourcedir%\file%fcount:~-2%.txt"
GOTO :EOF

Here's a native windows batch that should accomplish the task.

Now I'll not say that it'll be fast (less than 2 minutes for each 5Kline output file) or that it will be immune to batch character-sensitivites. Really depends on the characteristics of your target data.

I used a file named q25249516.txt containing 100Klines of data for my testing.


Revised quicker version

REM

@ECHO OFF
SETLOCAL
SET "sourcedir=U:\sourcedir"
SET /a fcount=199
SET /a llimit=5000
SET /a lcount=%llimit%
FOR /f "usebackqdelims=" %%a IN ("%sourcedir%\q25249516.txt") DO (
 CALL :select
 >>"%sourcedir%\file$$.txt" ECHO(%%a
)
SET /a lcount=%llimit%
:select
SET /a lcount+=1
IF %lcount% lss %llimit% GOTO :EOF
SET /a lcount=0
SET /a fcount+=1
MOVE /y "%sourcedir%\file$$.txt" "%sourcedir%\file%fcount:~-2%.txt" >NUL 2>nul
GOTO :EOF

Note that I used llimit of 50000 for testing. Will overwrite the early file numbers if llimit*100 is gearter than the number of lines in the file (cure by setting fcount to 1999 and use ~3 in place of ~2 in file-renaming line.)

How to add an element to the beginning of an OrderedDict?

EDIT (2019-02-03) Note that the following answer only works on older versions of Python. More recently, OrderedDict has been rewritten in C. In addition this does touch double-underscore attributes which is frowned upon.

I just wrote a subclass of OrderedDict in a project of mine for a similar purpose. Here's the gist.

Insertion operations are also constant time O(1) (they don't require you to rebuild the data structure), unlike most of these solutions.

>>> d1 = ListDict([('a', '1'), ('b', '2')])
>>> d1.insert_before('a', ('c', 3))
>>> d1
ListDict([('c', 3), ('a', '1'), ('b', '2')])

CLEAR SCREEN - Oracle SQL Developer shortcut?

Use cl scr on the Sql* command line tool to clear all the matter on the screen.

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);

Demo

Very Simple Image Slider/Slideshow with left and right button. No autoplay

After reading your comment on my previous answer I thought I might put this as a separate answer.

Although I appreciate your approach of trying to do it manually to get a better grasp on jQuery I do still emphasise the merit in using existing frameworks.

That said, here is a solution. I've modified some of your css and and HTML just to make it easier for me to work with

WORKING JS FIDDLE - http://jsfiddle.net/HsEne/15/

This is the jQuery

$(document).ready(function(){
$('.sp').first().addClass('active');
$('.sp').hide();    
$('.active').show();

    $('#button-next').click(function(){

    $('.active').removeClass('active').addClass('oldActive');    
                   if ( $('.oldActive').is(':last-child')) {
        $('.sp').first().addClass('active');
        }
        else{
        $('.oldActive').next().addClass('active');
        }
    $('.oldActive').removeClass('oldActive');
    $('.sp').fadeOut();
    $('.active').fadeIn();


    });

       $('#button-previous').click(function(){
    $('.active').removeClass('active').addClass('oldActive');    
           if ( $('.oldActive').is(':first-child')) {
        $('.sp').last().addClass('active');
        }
           else{
    $('.oldActive').prev().addClass('active');
           }
    $('.oldActive').removeClass('oldActive');
    $('.sp').fadeOut();
    $('.active').fadeIn();
    });




});

So now the explanation.
Stage 1
1) Load the script on document ready.

2) Grab the first slide and add a class 'active' to it so we know which slide we are dealing with.

3) Hide all slides and show active slide. So now slide #1 is display block and all the rest are display:none;

Stage 2 Working with the button-next click event.
1) Remove the current active class from the slide that will be disappearing and give it the class oldActive so we know that it is on it's way out.

2) Next is an if statement to check if we are at the end of the slideshow and need to return to the start again. It checks if oldActive (i.e. the outgoing slide) is the last child. If it is, then go back to the first child and make it 'active'. If it's not the last child, then just grab the next element (using .next() ) and give it class active.

3) We remove the class oldActive because it's no longer needed.

4) fadeOut all of the slides

5) fade In the active slides

Step 3

Same as in step two but using some reverse logic for traversing through the elements backwards.

It's important to note there are thousands of ways you can achieve this. This is merely my take on the situation.

Error :- java runtime environment JRE or java development kit must be available in order to run eclipse

Step 1

My computer > properties > Advance system settings

Step 2

environment variables > click New button under user variables > Enter variable name as 'PATH'

Copy the location of java bin (e.g:C:\Program Files\Java\jdk1.8.0_121\bin) and paste it in Variable value and click OK Now open the eclipse.

Include another HTML file in a HTML file

I came to this topic looking for something similar, but a bit different from the problem posed by lolo. I wanted to construct an HTML page holding an alphabetical menu of links to other pages, and each of the other pages might or might not exist, and the order in which they were created might not be alphabetical (nor even numerical). Also, like Tafkadasoh, I did not want to bloat the web page with jQuery. After researching the problem and experimenting for several hours, here is what worked for me, with relevant remarks added:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
  <meta http-equiv="Content-Type" content="text/application/html; charset=iso-8859-1">
  <meta name="Author" content="me">
  <meta copyright="Copyright" content= "(C) 2013-present by me" />
  <title>Menu</title>

<script type="text/javascript">
<!--
var F000, F001, F002, F003, F004, F005, F006, F007, F008, F009,
    F010, F011, F012, F013, F014, F015, F016, F017, F018, F019;
var dat = new Array();
var form, script, write, str, tmp, dtno, indx, unde;

/*
The "F000" and similar variables need to exist/be-declared.
Each one will be associated with a different menu item,
so decide on how many items maximum you are likely to need,
when constructing that listing of them.  Here, there are 20.
*/


function initialize()
{ window.name="Menu";
  form = document.getElementById('MENU');
  for(indx=0; indx<20; indx++)
  { str = "00" + indx;
    tmp = str.length - 3;
    str = str.substr(tmp);
    script = document.createElement('script');
    script.type = 'text/javascript';
    script.src = str + ".js";
    form.appendChild(script);
  }

/*
The for() loop constructs some <script> objects
and associates each one with a different simple file name,
starting with "000.js" and, here, going up to "019.js".
It won't matter which of those files exist or not.
However, for each menu item you want to display on this
page, you will need to ensure that its .js file does exist.

The short function below (inside HTML comment-block) is,
generically, what the content of each one of the .js files looks like:
<!--
function F000()
{ return ["Menu Item Name", "./URLofFile.htm", "Description string"];
}
-->

(Continuing the remarks in the main menu.htm file)
It happens that each call of the form.appendChild() function
will cause the specified .js script-file to be loaded at that time.
However, it takes a bit of time for the JavaScript in the file
to be fully integrated into the web page, so one thing that I tried,
but it didn't work, was to write an "onload" event handler.
The handler was apparently being called before the just-loaded
JavaScript had actually become accessible.

Note that the name of the function in the .js file is the same as one
of the pre-defined variables like "F000".  When I tried to access
that function without declaring the variable, attempting to use an
"onload" event handler, the JavaScript debugger claimed that the item
was "not available".  This is not something that can be tested-for!
However, "undefined" IS something that CAN be tested-for.  Simply
declaring them to exist automatically makes all of them "undefined".
When the system finishes integrating a just-loaded .js script file,
the appropriate variable, like "F000", will become something other
than "undefined".  Thus it doesn't matter which .js files exist or
not, because we can simply test all the "F000"-type variables, and
ignore the ones that are "undefined".  More on that later.

The line below specifies a delay of 2 seconds, before any attempt
is made to access the scripts that were loaded.  That DOES give the
system enough time to fully integrate them into the web page.
(If you have a really long list of menu items, or expect the page
to be loaded by an old/slow computer, a longer delay may be needed.)
*/

  window.setTimeout("BuildMenu();", 2000);
  return;
}


//So here is the function that gets called after the 2-second delay  
function BuildMenu()
{ dtno = 0;    //index-counter for the "dat" array
  for(indx=0; indx<20; indx++)
  { str = "00" + indx;
    tmp = str.length - 3;
    str = "F" + str.substr(tmp);
    tmp = eval(str);
    if(tmp != unde) // "unde" is deliberately undefined, for this test
      dat[dtno++] = eval(str + "()");
  }

/*
The loop above simply tests each one of the "F000"-type variables, to
see if it is "undefined" or not.  Any actually-defined variable holds
a short function (from the ".js" script-file as previously indicated).
We call the function to get some data for one menu item, and put that
data into an array named "dat".

Below, the array is sorted alphabetically (the default), and the
"dtno" variable lets us know exactly how many menu items we will
be working with.  The loop that follows creates some "<span>" tags,
and the the "innerHTML" property of each one is set to become an
"anchor" or "<a>" tag, for a link to some other web page.  A description
and a "<br />" tag gets included for each link.  Finally, each new
<span> object is appended to the menu-page's "form" object, and thereby
ends up being inserted into the middle of the overall text on the page.
(For finer control of where you want to put text in a page, consider
placing something like this in the web page at an appropriate place,
as preparation:
<div id="InsertHere"></div>
You could then use document.getElementById("InsertHere") to get it into
a variable, for appending of <span> elements, the way a variable named
"form" was used in this example menu page.

Note: You don't have to specify the link in the same way I did
(the type of link specified here only works if JavaScript is enabled).
You are free to use the more-standard "<a>" tag with the "href"
property defined, if you wish.  But whichever way you go,
you need to make sure that any pages being linked actually exist!
*/

  dat.sort();
  for(indx=0; indx<dtno; indx++)
  { write = document.createElement('span');
    write.innerHTML = "<a onclick=\"window.open('" + dat[indx][1] +
                      "', 'Menu');\" style=\"color:#0000ff;" + 
                      "text-decoration:underline;cursor:pointer;\">" +
                      dat[indx][0] + "</a> " + dat[indx][2] + "<br />";
    form.appendChild(write);
  }
  return;
}

// -->
</script>
</head>

<body onload="initialize();" style="background-color:#a0a0a0; color:#000000; 

font-family:sans-serif; font-size:11pt;">
<h2>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;MENU
<noscript><br /><span style="color:#ff0000;">
Links here only work if<br />
your browser's JavaScript<br />
support is enabled.</span><br /></noscript></h2>
These are the menu items you currently have available:<br />
<br />
<form id="MENU" action="" onsubmit="return false;">
<!-- Yes, the <form> object starts out completely empty -->
</form>
Click any link, and enjoy it as much as you like.<br />
Then use your browser's BACK button to return to this Menu,<br />
so you can click a different link for a different thing.<br />
<br />
<br />
<small>This file (web page) Copyright (c) 2013-present by me</small>
</body>
</html>

JavaScript: How to find out if the user browser is Chrome?

If you're feeling brave, you can experiment with browser sniffing and get a version:

var ua = navigator.userAgent;
if(/chrome/i.test(ua)) {
    var uaArray = ua.split(' ')
    ,   version = uaArray[uaArray.length - 2].substr(7);
}

This detected version might be a Chrome version, or a Edge version, or something else. Browser plugins can easily change userAgent and platform and other things though, so this is not recommended.

Apologies to The Big Lebowski for using his answer within mine.

How to make HTML input tag only accept numerical values?

I use this for Zip Codes, quick and easy.

<input type="text" id="zip_code" name="zip_code" onkeypress="return event.charCode > 47 && event.charCode < 58;" pattern="[0-9]{5}" required></input>

Could not find module "@angular-devkit/build-angular"

This error generally occurs when the angular project was not configure completely.

This will work

npm install --save-dev @angular-devkit/build-angular

npm install

How to create a release signed apk file using Gradle?

An alternative is to define a task that runs only on release builds.

android {
  ...
  signingConfigs {
     release {
        // We can leave these in environment variables
        storeFile file('nameOfKeystore.keystore')
        keyAlias 'nameOfKeyAlias'

        // These two lines make gradle believe that the signingConfigs
        // section is complete. Without them, tasks like installRelease
        // will not be available!
        storePassword "notYourRealPassword"
        keyPassword "notYourRealPassword"

     }
  }
  buildTypes {
     ...
     release {
        signingConfig signingConfigs.release
        ...
     }
  }
  ...
}

task setupKeystore << {
final Console console = System.console();
if (console != null) {
    //def keyFile = console.readLine(“\nProject: “ + project.name + “Enter keystore path: "))
    //def keyAlias = console.readLine(“Project: “ + project.name + “Enter key alias: ")
        def storePw = new String(console.readPassword(“Project: “ + project.name + “. Enter keystore password: "))
        def keyPw  = new String(console.readPassword(“Project: “ + project.name + “.Enter keystore password: "))

    //android.signingConfigs.release.storeFile = file(keyFile);
    //android.signingConfigs.release.keyAlias = keyAlias
        android.signingConfigs.release.storePassword = storePw
        android.signingConfigs.release.keyPassword = keyPw
}
}

//Validate t
def isReleaseConfig = gradle.startParameter.taskNames.any {it.contains('Release') }
if (isReleaseConfig) {
    setupKeystore.execute();
}

Get statistics for each group (such as count, mean, etc) using pandas GroupBy?

Swiss Army Knife: GroupBy.describe

Returns count, mean, std, and other useful statistics per-group.

df.groupby(['A', 'B'])['C'].describe()

           count  mean   std   min   25%   50%   75%   max
A   B                                                     
bar one      1.0  0.40   NaN  0.40  0.40  0.40  0.40  0.40
    three    1.0  2.24   NaN  2.24  2.24  2.24  2.24  2.24
    two      1.0 -0.98   NaN -0.98 -0.98 -0.98 -0.98 -0.98
foo one      2.0  1.36  0.58  0.95  1.15  1.36  1.56  1.76
    three    1.0 -0.15   NaN -0.15 -0.15 -0.15 -0.15 -0.15
    two      2.0  1.42  0.63  0.98  1.20  1.42  1.65  1.87

To get specific statistics, just select them,

df.groupby(['A', 'B'])['C'].describe()[['count', 'mean']]

           count      mean
A   B                     
bar one      1.0  0.400157
    three    1.0  2.240893
    two      1.0 -0.977278
foo one      2.0  1.357070
    three    1.0 -0.151357
    two      2.0  1.423148

describe works for multiple columns (change ['C'] to ['C', 'D']—or remove it altogether—and see what happens, the result is a MultiIndexed columned dataframe).

You also get different statistics for string data. Here's an example,

df2 = df.assign(D=list('aaabbccc')).sample(n=100, replace=True)

with pd.option_context('precision', 2):
    display(df2.groupby(['A', 'B'])
               .describe(include='all')
               .dropna(how='all', axis=1))

              C                                                   D                
          count  mean       std   min   25%   50%   75%   max count unique top freq
A   B                                                                              
bar one    14.0  0.40  5.76e-17  0.40  0.40  0.40  0.40  0.40    14      1   a   14
    three  14.0  2.24  4.61e-16  2.24  2.24  2.24  2.24  2.24    14      1   b   14
    two     9.0 -0.98  0.00e+00 -0.98 -0.98 -0.98 -0.98 -0.98     9      1   c    9
foo one    22.0  1.43  4.10e-01  0.95  0.95  1.76  1.76  1.76    22      2   a   13
    three  15.0 -0.15  0.00e+00 -0.15 -0.15 -0.15 -0.15 -0.15    15      1   c   15
    two    26.0  1.49  4.48e-01  0.98  0.98  1.87  1.87  1.87    26      2   b   15

For more information, see the documentation.


pandas >= 1.1: DataFrame.value_counts

This is available from pandas 1.1 if you just want to capture the size of every group, this cuts out the GroupBy and is faster.

df.value_counts(subset=['col1', 'col2'])

Minimal Example

# Setup
np.random.seed(0)
df = pd.DataFrame({'A' : ['foo', 'bar', 'foo', 'bar',
                          'foo', 'bar', 'foo', 'foo'],
                   'B' : ['one', 'one', 'two', 'three',
                          'two', 'two', 'one', 'three'],
                   'C' : np.random.randn(8),
                   'D' : np.random.randn(8)})

df.value_counts(['A', 'B']) 

A    B    
foo  two      2
     one      2
     three    1
bar  two      1
     three    1
     one      1
dtype: int64

Other Statistical Analysis Tools

If you didn't find what you were looking for above, the User Guide has a comprehensive listing of supported statical analysis, correlation, and regression tools.

Producer/Consumer threads using a Queue

OK, as others note, the best thing to do is to use java.util.concurrent package. I highly recommend "Java Concurrency in Practice". It's a great book that covers almost everything you need to know.

As for your particular implementation, as I noted in the comments, don't start Threads from Constructors -- it can be unsafe.

Leaving that aside, the second implementation seem better. You don't want to put queues in static fields. You are probably just loosing flexibility for nothing.

If you want to go ahead with your own implementation (for learning purpose I guess?), supply a start() method at least. You should construct the object (you can instantiate the Thread object), and then call start() to start the thread.

Edit: ExecutorService have their own queue so this can be confusing.. Here's something to get you started.

public class Main {
    public static void main(String[] args) {
        //The numbers are just silly tune parameters. Refer to the API.
        //The important thing is, we are passing a bounded queue.
        ExecutorService consumer = new ThreadPoolExecutor(1,4,30,TimeUnit.SECONDS,new LinkedBlockingQueue<Runnable>(100));

        //No need to bound the queue for this executor.
        //Use utility method instead of the complicated Constructor.
        ExecutorService producer = Executors.newSingleThreadExecutor();

        Runnable produce = new Produce(consumer);
        producer.submit(produce);   
    }
}

class Produce implements Runnable {
    private final ExecutorService consumer;

    public Produce(ExecutorService consumer) {
        this.consumer = consumer;
    }

    @Override
    public void run() {
        Pancake cake = Pan.cook();
        Runnable consume = new Consume(cake);
        consumer.submit(consume);
    }
}

class Consume implements Runnable {
    private final Pancake cake;

    public Consume(Pancake cake){
        this.cake = cake;
    }

    @Override
    public void run() {
        cake.eat();
    }
}

Further EDIT: For producer, instead of while(true), you can do something like:

@Override
public void run(){
    while(!Thread.currentThread().isInterrupted()){
        //do stuff
    }
}

This way you can shutdown the executor by calling .shutdownNow(). If you'd use while(true), it won't shutdown.

Also note that the Producer is still vulnerable to RuntimeExceptions (i.e. one RuntimeException will halt the processing)

How to run an awk commands in Windows?

You can download and run the setup file. This should install your AWK in "C:\Program Files (x86)\GnuWin32". You can run the awk or gawk command from the bin folder or add the folder ``C:\Program Files (x86)\GnuWin32\binto yourPATH`.

enter image description here

Why did my Git repo enter a detached HEAD state?

When you checkout to a commit git checkout <commit-hash> or to a remote branch your HEAD will get detached and try to create a new commit on it.

Commits that are not reachable by any branch or tag will be garbage collected and removed from the repository after 30 days.

Another way to solve this is by creating a new branch for the newly created commit and checkout to it. git checkout -b <branch-name> <commit-hash>

This article illustrates how you can get to detached HEAD state.

How to make g++ search for header files in a specific directory?

gcc -I/path -L/path
  • -I /path path to include, gcc will find .h files in this path

  • -L /path contains library files, .a, .so

Is Android using NTP to sync time?

I know about Android ICS that it uses a custom service called: NetworkTimeUpdateService. This service also implements a NTP time synchronization via the NtpTrustedTime singleton.

In NtpTrustedTime the default NTP server is requested from the Android system string source:

final Resources res = context.getResources();

final String defaultServer = res.getString(
                                com.android.internal.R.string.config_ntpServer);

If the automatic time sync option in the system settings is checked and no NITZ time service is available then the time will be synchronized with the NTP server from com.android.internal.R.string.config_ntpServer.

To get the value of com.android.internal.R.string.config_ntpServer you can use the following method:

    final Resources res = this.getResources();
    final int id = Resources.getSystem().getIdentifier(
                       "config_ntpServer", "string","android");
    final String defaultServer = res.getString(id);

How to install multiple python packages at once using pip

You can simply place multiple name together separated by a white space like

C:\Users\Dell>pip install markdown django-filter

#c:\Users\Dell is path in my pc this can be anything on yours

this installed markdown and django-filter on my device. enter image description here

Using Application context everywhere?

I'm using the same approach, I suggest to write the singleton a little better:

public static MyApp getInstance() {

    if (instance == null) {
        synchronized (MyApp.class) {
            if (instance == null) {
                instance = new MyApp ();
            }
        }
    }

    return instance;
}

but I'm not using everywhere, I use getContext() and getApplicationContext() where I can do it!

Difference between npx and npm?

npx is a npm package runner (x probably stands for eXecute). The typical use is to download and run a package temporarily or for trials.

create-react-app is an npm package that is expected to be run only once in a project's lifecycle. Hence, it is preferred to use npx to install and run it in a single step.

As mentioned in the man page https://www.npmjs.com/package/npx, npx can run commands in the PATH or from node_modules/.bin by default.

Note: With some digging, we can find that create-react-app points to a Javascript file (possibly to /usr/lib/node_modules/create-react-app/index.js on Linux systems) that is executed within the node environment. This is simply a global tool that does some checks. The actual setup is done by react-scripts, whose latest version is installed in the project. Refer https://github.com/facebook/create-react-app for more info.

How to mock private method for testing using PowerMock?

I don't see a problem here. With the following code using the Mockito API, I managed to do just that :

public class CodeWithPrivateMethod {

    public void meaningfulPublicApi() {
        if (doTheGamble("Whatever", 1 << 3)) {
            throw new RuntimeException("boom");
        }
    }

    private boolean doTheGamble(String whatever, int binary) {
        Random random = new Random(System.nanoTime());
        boolean gamble = random.nextBoolean();
        return gamble;
    }
}

And here's the JUnit test :

import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import static org.mockito.Matchers.anyInt;
import static org.mockito.Matchers.anyString;
import static org.powermock.api.mockito.PowerMockito.when;
import static org.powermock.api.support.membermodification.MemberMatcher.method;

@RunWith(PowerMockRunner.class)
@PrepareForTest(CodeWithPrivateMethod.class)
public class CodeWithPrivateMethodTest {

    @Test(expected = RuntimeException.class)
    public void when_gambling_is_true_then_always_explode() throws Exception {
        CodeWithPrivateMethod spy = PowerMockito.spy(new CodeWithPrivateMethod());

        when(spy, method(CodeWithPrivateMethod.class, "doTheGamble", String.class, int.class))
                .withArguments(anyString(), anyInt())
                .thenReturn(true);

        spy.meaningfulPublicApi();
    }
}

Java - Opposite of .contains (does not contain)

It seems that Luiggi Mendoza and joey rohan both already answered this, but I think it can be clarified a little.

You can write it as a single if statement:

if (inventory.contains("bread") && !inventory.contains("water")) {
    // do something
}

Could not load file or assembly 'System.Data.SQLite'

System.Data.SQLite has a dependency on System.Data.SQLite.interop make sure both packages are the same version and are both x86.

This is an old question, but I tried all the above. I was working on a strictly x86 project, so there was not two folders /x86, /x64. But for some reason, the System.Data.SQLite was a different version to System.Data.SQLite.interop, once I pulled down matching dlls the problem was fixed.

How to convert View Model into JSON object in ASP.NET MVC?

Extending the great answer from Dave. You can create a simple HtmlHelper.

public static IHtmlString RenderAsJson(this HtmlHelper helper, object model)
{
    return helper.Raw(Json.Encode(model));
}

And in your view:

@Html.RenderAsJson(Model)

This way you can centralize the logic for creating the JSON if you, for some reason, would like to change the logic later.

How do I verify that an Android apk is signed with a release certificate?

    1. unzip apk
    1. keytool -printcert -file ANDROID_.RSA or keytool -list -printcert -jarfile app.apk to obtain the hash md5
  • keytool -list -v -keystore clave-release.jks
  • compare the md5

https://www.eovao.com/en/a/signature%20apk%20android/3/how-to-verify-signature-of-.apk-android-archive

Trigger validation of all fields in Angular Form submit

Here is my global function for showing the form error messages.

 function show_validation_erros(form_error_object) {
        angular.forEach(form_error_object, function (objArrayFields, errorName) {
            angular.forEach(objArrayFields, function (objArrayField, key) {
                objArrayField.$setDirty();
            });
        });
    };

And in my any controllers,

if ($scope.form_add_sale.$invalid) { 
    $scope.global.show_validation_erros($scope.form_add_sale.$error);
}

Can Python test the membership of multiple values in a list?

Here's how I did it:

A = ['a','b','c']
B = ['c']
logic = [(x in B) for x in A]
if True in logic:
    do something

How to build a Horizontal ListView with RecyclerView?

 <HorizontalScrollView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            >
        <android.support.v7.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal"
            android:scrollbars="vertical|horizontal" />
        </HorizontalScrollView>

    import androidx.appcompat.app.AppCompatActivity;
    import android.content.Context;
    import android.content.ContextWrapper;
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.os.AsyncTask;
    import android.os.Bundle;
    import android.os.Environment;
    import android.view.View;
    import android.widget.ImageView;
    import android.widget.Toast;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.net.HttpURLConnection;
    public class MainActivity extends AppCompatActivity
     {
        ImageView mImageView1;
        Bitmap bitmap;
        String mSavedInfo;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            mImageView1 = (ImageView) findViewById(R.id.image);
        }
        public Bitmap getBitmapFromURL(String src) {
            try {
                java.net.URL url = new java.net.URL(src);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setDoInput(true);
                connection.connect();
                InputStream input = connection.getInputStream();
                Bitmap myBitmap = BitmapFactory.decodeStream(input);
                return myBitmap;
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            }
        }
        public void button2(View view) {
            new DownloadImageFromTherad().execute();
        }
        private class DownloadImageFromTherad extends AsyncTask<String, Integer, String> {
            @Override
            protected String doInBackground(String... params) {
                bitmap = getBitmapFromURL("https://cdn.pixabay.com/photo/2016/08/08/09/17/avatar-1577909_960_720.png");
                return null;
            }

            @Override
            protected void onPostExecute(String s) {
                super.onPostExecute(s);
                File sdCardDirectory = Environment.getExternalStorageDirectory();
                File image = new File(sdCardDirectory, "test.png");
                boolean success = false;
                FileOutputStream outStream;
                mSavedInfo = saveToInternalStorage(bitmap);
                if (success) {
                    Toast.makeText(getApplicationContext(), "Image saved with success", Toast.LENGTH_LONG).show();
                } else {
                    Toast.makeText(getApplicationContext(), "Error during image saving" + mSavedInfo, Toast.LENGTH_LONG).show();
                }
            }
        }
        private String saveToInternalStorage(Bitmap bitmapImage) {
            ContextWrapper cw = new ContextWrapper(getApplicationContext());
            // path to /data/data/yourapp/app_data/imageDir
            File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
            File mypath = new File(directory, "profile.jpg");
            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(mypath);
                bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fos);
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return directory.getAbsolutePath();
        }
        private void loadImageFromStorage(String path) {
            try {
                File f = new File(path, "profile.jpg");
                Bitmap b = BitmapFactory.decodeStream(new FileInputStream(f));
                mImageView1.setImageBitmap(b);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }
        public void showImage(View view) {
            loadImageFromStorage(mSavedInfo);
        }
    }

Best way to iterate through a Perl array

  • In terms of speed: #1 and #4, but not by much in most instances.

    You could write a benchmark to confirm, but I suspect you'll find #1 and #4 to be slightly faster because the iteration work is done in C instead of Perl, and no needless copying of the array elements occurs. ($_ is aliased to the element in #1, but #2 and #3 actually copy the scalars from the array.)

    #5 might be similar.

  • In terms memory usage: They're all the same except for #5.

    for (@a) is special-cased to avoid flattening the array. The loop iterates over the indexes of the array.

  • In terms of readability: #1.

  • In terms of flexibility: #1/#4 and #5.

    #2 does not support elements that are false. #2 and #3 are destructive.

How to drop rows of Pandas DataFrame whose value in a certain column is NaN

Don't drop, just take the rows where EPS is not NA:

df = df[df['EPS'].notna()]

How to strip HTML tags with jQuery?

This is a example for get the url image, escape the p tag from some item.

Try this:

$('#img').attr('src').split('<p>')[1].split('</p>')[0]

Reading from stdin

You can do something like this to read 10 bytes:

char buffer[10];
read(STDIN_FILENO, buffer, 10);

remember read() doesn't add '\0' to terminate to make it string (just gives raw buffer).

To read 1 byte at a time:

char ch;
while(read(STDIN_FILENO, &ch, 1) > 0)
{
 //do stuff
}

and don't forget to #include <unistd.h>, STDIN_FILENO defined as macro in this file.

There are three standard POSIX file descriptors, corresponding to the three standard streams, which presumably every process should expect to have:

Integer value   Name
       0        Standard input (stdin)
       1        Standard output (stdout)
       2        Standard error (stderr)

So instead STDIN_FILENO you can use 0.

Edit:
In Linux System you can find this using following command:

$ sudo grep 'STDIN_FILENO' /usr/include/* -R | grep 'define'
/usr/include/unistd.h:#define   STDIN_FILENO    0   /* Standard input.  */

Notice the comment /* Standard input. */

How to format numbers?

Use

num = num.toFixed(2);

Where 2 is the number of decimal places

Edit:

Here's the function to format number as you want

function formatNumber(number)
{
    number = number.toFixed(2) + '';
    x = number.split('.');
    x1 = x[0];
    x2 = x.length > 1 ? '.' + x[1] : '';
    var rgx = /(\d+)(\d{3})/;
    while (rgx.test(x1)) {
        x1 = x1.replace(rgx, '$1' + ',' + '$2');
    }
    return x1 + x2;
}

Sorce: www.mredkj.com

How to download a file over HTTP?

You can use PycURL on Python 2 and 3.

import pycurl

FILE_DEST = 'pycurl.html'
FILE_SRC = 'http://pycurl.io/'

with open(FILE_DEST, 'wb') as f:
    c = pycurl.Curl()
    c.setopt(c.URL, FILE_SRC)
    c.setopt(c.WRITEDATA, f)
    c.perform()
    c.close()

LINQ Join with Multiple Conditions in On Clause

Here you go with:

from b in _dbContext.Burden 
join bl in _dbContext.BurdenLookups on
new { Organization_Type = b.Organization_Type_ID, Cost_Type = b.Cost_Type_ID } equals
new { Organization_Type = bl.Organization_Type_ID, Cost_Type = bl.Cost_Type_ID }

HorizontalAlignment=Stretch, MaxWidth, and Left aligned at the same time?

Both answers given worked for the problem I stated -- Thanks!

In my real application though, I was trying to constrain a panel inside of a ScrollViewer and Kent's method didn't handle that very well for some reason I didn't bother to track down. Basically the controls could expand beyond the MaxWidth setting and defeated my intent.

Nir's technique worked well and didn't have the problem with the ScrollViewer, though there is one minor thing to watch out for. You want to be sure the right and left margins on the TextBox are set to 0 or they'll get in the way. I also changed the binding to use ViewportWidth instead of ActualWidth to avoid issues when the vertical scrollbar appeared.

Remove shadow below actionbar

For those working on fragments and it disappeared after setting toolbar.getBackground().setAlpha(0); or any disappearance, i think you have to bring your AppBarLayout to the last in the xml, so its Fragment then AppBarLayout then relativelayout/constraint/linear whichever u use.

How do I replace a double-quote with an escape-char double-quote in a string using JavaScript?

The other answers will work for most strings, but you can end up unescaping an already escaped double quote, which is probably not what you want.

To work correctly, you are going to need to escape all backslashes and then escape all double quotes, like this:

var test_str = '"first \\" middle \\" last "';
var result = test_str.replace(/\\/g, '\\\\').replace(/\"/g, '\\"');

depending on how you need to use the string, and the other escaped charaters involved, this may still have some issues, but I think it will probably work in most cases.

How to get length of a string using strlen function

Manually:

int strlen(string s)
{
    int len = 0;

    while (s[len])
        len++;

    return len;
}

A fatal error occurred while creating a TLS client credential. The internal error state is 10013

After making no changes to a production server we began receiving this error. After trying several different things and thinking that perhaps there were DNS issues, restarting IIS fixed the issue (restarting only the site did not fix the issue). It likely won't work for everyone but if we tried that first it would have saved a lot of time.

Fit image into ImageView, keep aspect ratio and then resize ImageView to image dimensions?

I needed to get this done in a constraint layout with Picasso, so I munged together some of the above answers and came up with this solution (I already know the aspect ratio of the image I'm loading, so that helps):

Called in my activity code somewhere after setContentView(...)

protected void setBoxshotBackgroundImage() {
    ImageView backgroundImageView = (ImageView) findViewById(R.id.background_image_view);

    if(backgroundImageView != null) {
        DisplayMetrics displayMetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        int width = displayMetrics.widthPixels;
        int height = (int) Math.round(width * ImageLoader.BOXART_HEIGHT_ASPECT_RATIO);

        // we adjust the height of this element, as the width is already pinned to the parent in xml
        backgroundImageView.getLayoutParams().height = height;

        // implement your Picasso loading code here
    } else {
        // fallback if no element in layout...
    }
}

In my XML

<?xml version="1.0" encoding="utf-8"?>

<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:layout_editor_absoluteY="0dp"
tools:layout_editor_absoluteX="0dp">

    <ImageView
        android:id="@+id/background_image_view"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:scaleType="fitStart"
        app:srcCompat="@color/background"
        android:adjustViewBounds="true"
        tools:layout_editor_absoluteY="0dp"
        android:layout_marginTop="0dp"
        android:layout_marginBottom="0dp"
        android:layout_marginRight="0dp"
        android:layout_marginLeft="0dp"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <!-- other elements of this layout here... -->

</android.support.constraint.ConstraintLayout>

Note the lack of a constraintBottom_toBottomOf attribute. ImageLoader is my own static class for image loading util methods and constants.

How to customise the Jackson JSON mapper implicitly used by Spring Boot?

I know the question asking for Spring boot, but I believe lot of people looking for how to do this in non Spring boot, like me searching almost whole day.

Above Spring 4, there is no need to configure MappingJacksonHttpMessageConverter if you only intend to configure ObjectMapper.

You just need to do:

public class MyObjectMapper extends ObjectMapper {

    private static final long serialVersionUID = 4219938065516862637L;

    public MyObjectMapper() {
        super();
        enable(SerializationFeature.INDENT_OUTPUT);
    }       
}

And in your Spring configuration, create this bean:

@Bean 
public MyObjectMapper myObjectMapper() {        
    return new MyObjectMapper();
}

Drop all tables whose names begin with a certain string

CREATE PROCEDURE usp_GenerateDROP
    @Pattern AS varchar(255)
    ,@PrintQuery AS bit
    ,@ExecQuery AS bit
AS
BEGIN
    DECLARE @sql AS varchar(max)

    SELECT @sql = COALESCE(@sql, '') + 'DROP TABLE [' + TABLE_NAME + ']' + CHAR(13) + CHAR(10)
    FROM INFORMATION_SCHEMA.TABLES
    WHERE TABLE_NAME LIKE @Pattern

    IF @PrintQuery = 1 PRINT @sql
    IF @ExecQuery = 1 EXEC (@sql)
END

How to force a UIViewController to Portrait orientation in iOS 6

I did not test it myself, but the documentation states that you can now override those methods: supportedInterfaceOrientations and preferredInterfaceOrientationForPresentation.

You can probably achieve what you want y setting only the orientation that you want in those methods.

DeprecationWarning: Buffer() is deprecated due to security and usability issues when I move my script to another server

The use of the deprecated new Buffer() constructor (i.E. as used by Yarn) can cause deprecation warnings. Therefore one should NOT use the deprecated/unsafe Buffer constructor.

According to the deprecation warning new Buffer() should be replaced with one of:

  • Buffer.alloc()
  • Buffer.allocUnsafe() or
  • Buffer.from()

Another option in order to avoid this issue would be using the safe-buffer package instead.

You can also try (when using yarn..):

yarn global add yarn

as mentioned here: Link

Another suggestion from the comments (thx to gkiely): self-update

Note: self-update is not available. See policies for enforcing versions within a project

In order to update your version of Yarn, run

curl --compressed -o- -L https://yarnpkg.com/install.sh | bash

SQLite with encryption/password protection

I had also similar problem. Needed to store sensitive data in simple database (SQLite was the perfect choice except security). Finally I have placed database file on TrueCrypt encrypted valume.

Additional console app mounts temporary drive using TrueCrypt CLI and then starts the database application. Waits until the database application exits and then dismounts the drive again.

Maybe not suitable solution in all scenarios but for me working well ...

json call with C#

Here's a variation of Shiv Kumar's answer, using Newtonsoft.Json (aka Json.NET):

public static bool SendAnSMSMessage(string message)
{
    var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://api.pennysms.com/jsonrpc");
    httpWebRequest.ContentType = "text/json";
    httpWebRequest.Method = "POST";

    var serializer = new Newtonsoft.Json.JsonSerializer();
    using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
    {
        using (var tw = new Newtonsoft.Json.JsonTextWriter(streamWriter))
        {
             serializer.Serialize(tw, 
                 new {method= "send",
                      @params = new string[]{
                          "IPutAGuidHere", 
                          "[email protected]",
                          "MyTenDigitNumberWasHere",
                          message
                      }});
        }
    }
    var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
    using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
    {
        var responseText = streamReader.ReadToEnd();
        //Now you have your response.
        //or false depending on information in the response
        return true;        
    }
}

Uninitialized constant ActiveSupport::Dependencies::Mutex (NameError)

I have faced this problem in many occassions when I try to start an old rails 2.3.5 project after having worked with rails 3>. In my case to solve the problem, I must do a rubygems update to version 1.4.2, this is:

sudo gem update --system 1.4.2

Difference between Hive internal tables and external tables?

Hive tables can be created as EXTERNAL or INTERNAL. This is a choice that affects how data is loaded, controlled, and managed.

Use EXTERNAL tables when:

  1. The data is also used outside of Hive. For example, the data files are read and processed by an existing program that doesn't lock the files.
  2. Data needs to remain in the underlying location even after a DROP TABLE. This can apply if you are pointing multiple schemas (tables or views) at a single data set or if you are iterating through various possible schemas.
  3. You want to use a custom location such as ASV.
  4. Hive should not own data and control settings, dirs, etc., you have another program or process that will do those things.
  5. You are not creating table based on existing table (AS SELECT).

Use INTERNAL tables when:

The data is temporary.

You want Hive to completely manage the lifecycle of the table and data.

Artisan, creating tables in database

Migration files must match the pattern *_*.php, or else they won't be found. Since users.php does not match this pattern (it has no underscore), this file will not be found by the migrator.

Ideally, you should be creating your migration files using artisan:

php artisan make:migration create_users_table

This will create the file with the appropriate name, which you can then edit to flesh out your migration. The name will also include the timestamp, to help the migrator determine the order of migrations.

You can also use the --create or --table switches to add a little bit more boilerplate to help get you started:

php artisan make:migration create_users_table --create=users

The documentation on migrations can be found here.

HTML form with side by side input fields

For the sake of bandwidth saving, we shouldn't include <div> for each of <label> and <input> pair

This solution may serve you better and may increase readability

<div class="form">
            <label for="product_name">Name</label>
            <input id="product_name" name="product[name]" size="30" type="text" value="4">
            <label for="product_stock">Stock</label>
            <input id="product_stock" name="product[stock]" size="30" type="text" value="-1">
            <label for="price_amount">Amount</label>
            <input id="price_amount" name="price[amount]" size="30" type="text" value="6.0">
</div>

The css for above form would be

.form > label
{
  float: left;
  clear: right;
}

.form > input
{
  float: right;
}

I believe the output would be as following:

Demo

Recommended website resolution (width and height)?

Ultimately, this is not a matter of standards or best practices for markup, but rather knowing your audience and making sure your website does what you want it to do.

It's more important to consider the width of the browser viewport rather than screen resolution -- you cannot assume that every pixel on a display will be allocated to the browser (and even if it is, you have to subtract browser chrome). If you have access to analytics that report browser width (n.b. browser width, not screen resolution) then pay very close attention.

It's nice to try to accommodate the widest possible range of viewports but there are some limitations. Some challenges can be handled with CSS media types, some can't. Some can be handled with fluid layouts. But fluid layouts cannot work in all situations, depending on the type of information to be displayed, line length, reading comfort, etc. Some fluid layouts don't work in wide displays. Most break when sized below a certain width, etc.

As much as I'd personally like to design for viewports ~960 pixels and up, you can't always do it. So in some cases, it's still safest to design for viewports <=760 pixels or so (800 pixel wide display, maximized) -- though the time we can finally toss this limitation once and for all -- for the desktop at least -- is very fast approaching.

Where conversions are an issue -- and you have a fixed width layout -- you better have a darned good reason for putting anything that the user needs to click in order for the cash register to go "ka-ching" anywhere east of the 760th pixel.

Ditto for the primary navigation.

Finally, test your layout in everything you can get your hands on. Big. Small. Desktop. Handheld. The works. There's no substitute.

How can I login to a website with Python?

Typically you'll need cookies to log into a site, which means cookielib, urllib and urllib2. Here's a class which I wrote back when I was playing Facebook web games:

import cookielib
import urllib
import urllib2

# set these to whatever your fb account is
fb_username = "[email protected]"
fb_password = "secretpassword"

class WebGamePlayer(object):

    def __init__(self, login, password):
        """ Start up... """
        self.login = login
        self.password = password

        self.cj = cookielib.CookieJar()
        self.opener = urllib2.build_opener(
            urllib2.HTTPRedirectHandler(),
            urllib2.HTTPHandler(debuglevel=0),
            urllib2.HTTPSHandler(debuglevel=0),
            urllib2.HTTPCookieProcessor(self.cj)
        )
        self.opener.addheaders = [
            ('User-agent', ('Mozilla/4.0 (compatible; MSIE 6.0; '
                           'Windows NT 5.2; .NET CLR 1.1.4322)'))
        ]

        # need this twice - once to set cookies, once to log in...
        self.loginToFacebook()
        self.loginToFacebook()

    def loginToFacebook(self):
        """
        Handle login. This should populate our cookie jar.
        """
        login_data = urllib.urlencode({
            'email' : self.login,
            'pass' : self.password,
        })
        response = self.opener.open("https://login.facebook.com/login.php", login_data)
        return ''.join(response.readlines())

You won't necessarily need the HTTPS or Redirect handlers, but they don't hurt, and it makes the opener much more robust. You also might not need cookies, but it's hard to tell just from the form that you've posted. I suspect that you might, purely from the 'Remember me' input that's been commented out.

maxlength ignored for input type="number" in Chrome

Done! Numbers only and maxlength work perfect.

<input  maxlength="5" data-rule-maxlength="5" style="height:30px;width: 786px;" type="number"  oninput="javascript: if (this.value.length > this.maxLength) this.value = this.value.slice(0, this.maxLength); this.value = this.value.replace(/[^0-9.]/g, '').replace(/(\..*)\./g, '$1');" />

Corrupted Access .accdb file: "Unrecognized Database Format"

Well, I have tried something I hope it helps ..

They changed the schema a little bit ..

Use the following :

1- Change the AccessDataSource to SQLDataSource in the toolbox.

2- In the drop down menu choose your access database (xxxx.accdb or xxxx.mdb)

3- Next -> Next -> Test Query -> Finish.

Worked for me.

Save bitmap to location

Save Bitmap to your Gallery Without Compress.

private File saveBitMap(Context context, Bitmap Final_bitmap) {
    File pictureFileDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "Your Folder Name");
    if (!pictureFileDir.exists()) {
        boolean isDirectoryCreated = pictureFileDir.mkdirs();
        if (!isDirectoryCreated)
            Log.i("TAG", "Can't create directory to save the image");
        return null;
    }
    String filename = pictureFileDir.getPath() + File.separator + System.currentTimeMillis() + ".jpg";
    File pictureFile = new File(filename);
    try {
        pictureFile.createNewFile();
        FileOutputStream oStream = new FileOutputStream(pictureFile);
        Final_bitmap.compress(Bitmap.CompressFormat.PNG, 100, oStream);
        oStream.flush();
        oStream.close();
        Toast.makeText(Full_Screen_Activity.this, "Save Image Successfully..", Toast.LENGTH_SHORT).show();
    } catch (IOException e) {
        e.printStackTrace();
        Log.i("TAG", "There was an issue saving the image.");
    }
    scanGallery(context, pictureFile.getAbsolutePath());
    return pictureFile;
}
private void scanGallery(Context cntx, String path) {
    try {
        MediaScannerConnection.scanFile(cntx, new String[]{path}, null, new MediaScannerConnection.OnScanCompletedListener() {
            public void onScanCompleted(String path, Uri uri) {
                Toast.makeText(Full_Screen_Activity.this, "Save Image Successfully..", Toast.LENGTH_SHORT).show();
            }
        });
    } catch (Exception e) {
        e.printStackTrace();
        Log.i("TAG", "There was an issue scanning gallery.");
    }
}

ASP.NET MVC DropDownListFor with model of type List<string>

If you have a List of type string that you want in a drop down list I do the following:

EDIT: Clarified, making it a fuller example.

public class ShipDirectory
{
    public string ShipDirectoryName { get; set; }
    public List<string> ShipNames { get; set; }
}

ShipDirectory myShipDirectory = new ShipDirectory()
{
    ShipDirectoryName = "Incomming Vessels",
    ShipNames = new List<string>(){"A", "A B"},
}

myShipDirectory.ShipNames.Add("Aunt Bessy");

@Html.DropDownListFor(x => x.ShipNames, new SelectList(Model.ShipNames), "Select a Ship...", new { @style = "width:500px" })

Which gives a drop down list like so:

<select id="ShipNames" name="ShipNames" style="width:500px">
    <option value="">Select a Ship...</option>
    <option>A</option>
    <option>A B</option>
    <option>Aunt Bessy</option>
</select>

To get the value on a controllers post; if you are using a model (e.g. MyViewModel) that has the List of strings as a property, because you have specified x => x.ShipNames you simply have the method signature as (because it will be serialised/deserialsed within the model):

public ActionResult MyActionName(MyViewModel model)

Access the ShipNames value like so: model.ShipNames

If you just want to access the drop down list on post then the signature becomes:

public ActionResult MyActionName(string ShipNames)

EDIT: In accordance with comments have clarified how to access the ShipNames property in the model collection parameter.

What Ruby IDE do you prefer?

I started out using gEdit (ubuntu user), but even with all the plugins and modifications (class/file browser, terminal, darkmate scheme, etc, etc) it still always seemed to come up short. I've also tried like hell to get Aptana RadRails and Studio to work, but none of them ever really seemed to sync up with my workflow. I've even tried using Eclipse, but again, it just didn't work for me.

RubyMine also seemed like it would be great, but I found it to be way too buggy, even after the upgrade to 3.0.

So far, my favorite Ruby editor is Komodo Edit. It's got syntax highlighting and can detect errors and recognize your code based on user-specified ruby versions. Syntax highlighting schema are easily customizable and easy on the eyes. There are some very nice plugins for git, it can have split-screen editors (love that feature), and a great file-browser. I really wish Komodo had built-in terminal (multiple terminal) support, but everything else about it I've really come to love, and haven't found anything better yet.

@Value annotation type casting to Integer from String

I had the exact same situation. It was caused by not having a PropertySourcesPlaceholderConfigurer in the Spring context, which resolves values against the @Value annotation inside of classes.

Include a property placeholder to solve the problem, no need to use Spring expressions for integers (the property file does not have to exist if you use ignore-resource-not-found="true"):

<context:property-placeholder location="/path/to/my/app.properties"
    ignore-resource-not-found="true" />

python pandas dataframe columns convert to dict key and value

If lakes is your DataFrame, you can do something like

area_dict = dict(zip(lakes.area, lakes.count))

How do I find out what version of WordPress is running?

Just go to follow link domain.com/wp-admin/about.php

Unable to add window -- token android.os.BinderProxy is not valid; is your activity running?

This can occur when you are showing the dialog for a context that no longer exists. A common case - if the 'show dialog' operation is after an asynchronous operation, and during that operation the original activity (that is to be the parent of your dialog) is destroyed. For a good description, see this blog post and comments:

http://dimitar.me/android-displaying-dialogs-from-background-threads/

From the stack trace above, it appears that the facebook library spins off the auth operation asynchronously, and you have a Handler - Callback mechanism (onComplete called on a listener) that could easily create this scenario.

When I've seen this reported in my app, its pretty rare and matches the experience in the blog post. Something went wrong for the activity/it was destroyed during the work of the the AsyncTask. I don't know how your modification could result in this every time, but perhaps you are referencing an Activity as the context for the dialog that is always destroyed by the time your code executes?

Also, while I'm not sure if this is the best way to tell if your activity is running, see this answer for one method of doing so:

Check whether activity is active

Android: Changing Background-Color of the Activity (Main View)

if you put your full code here so i can help you. if your setting the listener in XML and calling the set background color on View so it will change the background color of the view means it ur Botton so put ur listener in ur activity and then change the color of your view

Print a div content using Jquery

Some jQuery research has failed, so I moved to JavaScript (thanks for your suggestion Anders).

And it is working well...

HTML

<div id='DivIdToPrint'>
    <p>This is a sample text for printing purpose.</p>
</div>
<p>Do not print.</p>
<input type='button' id='btn' value='Print' onclick='printDiv();'>

JavaScript

function printDiv() 
{

  var divToPrint=document.getElementById('DivIdToPrint');

  var newWin=window.open('','Print-Window');

  newWin.document.open();

  newWin.document.write('<html><body onload="window.print()">'+divToPrint.innerHTML+'</body></html>');

  newWin.document.close();

  setTimeout(function(){newWin.close();},10);

}

Change Orientation of Bluestack : portrait/landscape mode

New version 4.100.x.xxxx

Try this:

More Apps > Android Settings > Accessibility > Auto-rotate screen = Enabled

enter image description here

random.seed(): What does it do?

Here is my understanding. Every time we set a seed value, a "label" or " reference" is generated. The next random.function call is attached to this "label", so next time you call the same seed value and random.function, it will give you the same result.

np.random.seed( 3 )
print(np.random.randn()) # output: 1.7886284734303186

np.random.seed( 3 )
print(np.random.rand()) # different function. output: 0.5507979025745755

np.random.seed( 5 )
print(np.random.rand()) # different seed value. output: 0.22199317108973948

How do I use Comparator to define a custom sort order?

I will do something like this:

List<String> order = List.of("Red", "Green", "Magenta", "Silver");

Comparator.comparing(Car::getColor(), Comparator.comparingInt(c -> order.indexOf(c)))

All credits go to @Sean Patrick Floyd :)

Should I use Vagrant or Docker for creating an isolated environment?

They are very much complementary.

I have been using a combination of VirtualBox, Vagrant and Docker for all my projects for several months and have strongly felt the following benefits.

In Vagrant you can completely do away with any Chef solo provisioning and all you need your vagrant file to do is prepare a machine that runs a single small shell script that installs docker. This means that my Vagrantfiles for every project are almost identical and very simple.

Here is a typical Vagrantfile

# -*- mode: ruby -*-
# vi: set ft=ruby :
VAGRANTFILE_API_VERSION = "2"
Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
  config.vm.box = "mark2"
  config.vm.box_url = "http://cloud-images.ubuntu.com/vagrant/trusty/current/trusty-server-cloudimg-amd64-vagrant-disk1.box"
  [3000, 5000, 2345, 15672, 5672, 15674, 27017, 28017, 9200, 9300, 11211, 55674, 61614, 55672, 5671, 61613].each do |p|
    config.vm.network :forwarded_port, guest: p, host: p
  end
  config.vm.network :private_network, ip: "192.168.56.20"
  config.vm.synced_folder ".", "/vagrant", :type => "nfs"
  config.vm.provider :virtualbox do |vb|
    vb.customize ["modifyvm", :id, "--memory", "2048"]
    vb.customize ["modifyvm", :id, "--cpus", "2"]
  end
  # Bootstrap to Docker
  config.vm.provision :shell, path: "script/vagrant/bootstrap", :privileged => true
  # Build docker containers
  config.vm.provision :shell, path: "script/vagrant/docker_build", :privileged => true
  # Start containers
  # config.vm.provision :shell, path: "script/vagrant/docker_start", :privileged => true
end

The Bootstrap file that installs docker looks like this

#!/usr/bin/env bash
echo 'vagrant  ALL= (ALL:ALL) NOPASSWD: ALL' >> /etc/sudoers
apt-get update -y
apt-get install htop -y
apt-get install linux-image-extra-`uname -r` -y
apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 36A1D7869245C8950F966E92D8576A8BA88D21E9
echo deb http://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list
apt-get update -y
apt-get install lxc-docker -y
apt-get install curl -y

Now to get all the services I need running I have a docker_start script that looks somthing like this

#!/bin/bash
cd /vagrant
echo Starting required service containers
export HOST_NAME=192.168.56.20
# Start MongoDB
docker run --name=mongodb --detach=true --publish=27017:27017 --publish=28017:28017 dockerfile/mongodb
read -t5 -n1 -r -p "Waiting for mongodb to start..." key
# Start rabbitmq
docker run --name=rabbitmq --detach=true --publish=5671:5671 --publish=5672:5672 --publish=55672:55672 --publish=15672:15672 --publish=15674:15674 --publish=61613:61613 --env RABBITMQ_USER=guest --env RABBITMQ_PASS=guest rabbitmq
read -t5 -n1 -r -p "Waiting for rabbitmq to start..." key
# Start cache
docker run --name=memcached --detach=true --publish=11211:11211  ehazlett/memcached
read -t5 -n1 -r -p "Waiting for cache to start..." key
# Start elasticsearch
docker run --name=elasticsearch --detach=true --publish=9200:9200 --publish=9300:9300 dockerfile/elasticsearch
read -t5 -n1 -r -p "Waiting for elasticsearch to start..." key
echo "All services started"

In this example I am running MongoDB, Elastisearch, RabbitMQ and Memcached

A non-docker Chef solo configuration would be considerably more complicated.

A final big plus is gained when you are moving into production, translating the development environment over to an infrastructure of hosts that are all the same in that they just have enough config to run docker means very little work indeed.

If you interested I have a more detailed article on the development environment on my own web site at

Implementing A Vagrant / Docker Development Environment

End-line characters from lines read from text file, using Python

Simple. Use splitlines()

L = open("myFile.txt", "r").read().splitlines();
for line in L: 
    process(line) # this 'line' will not have '\n' character at the end

Code-first vs Model/Database-first

Database first approach example:

Without writing any code: ASP.NET MVC / MVC3 Database First Approach / Database first

And I think it is better than other approaches because data loss is less with this approach.

Best Practice: Initialize JUnit class fields in setUp() or at declaration?

I prefer readability first which most often does not use the setup method. I make an exception when a basic setup operation takes a long time and is repeated within each test.
At that point I move that functionality into a setup method using the @BeforeClass annotation (optimize later).

Example of optimization using the @BeforeClass setup method: I use dbunit for some database functional tests. The setup method is responsible for putting the database in a known state (very slow... 30 seconds - 2 minutes depending on amount of data). I load this data in the setup method annotated with @BeforeClass and then run 10-20 tests against the same set of data as opposed to re-loading/initializing the database inside each test.

Using Junit 3.8 (extending TestCase as shown in your example) requires writing a little more code than just adding an annotation, but the "run once before class setup" is still possible.

continuing execution after an exception is thrown in java

Try this:

try
{
    throw new InvalidEmployeeTypeException();
    input.nextLine();
}
catch(InvalidEmployeeTypeException ex)
{
      //do error handling
}

continue;

Changing the CommandTimeout in SQL Management studio

Changing Command Execute Timeout in Management Studio:

Click on Tools -> Options

Select Query Execution from tree on left side and enter command timeout in "Execute Timeout" control.

Changing Command Timeout in Server:

In the object browser tree right click on the server which give you timeout and select "Properties" from context menu.

Now in "Server Properties -....." dialog click on "Connections" page in "Select a Page" list (on left side). On the right side you will get property

Remote query timeout (in seconds, 0 = no timeout):
[up/down control]

you can set the value in up/down control.

Failed to load ApplicationContext from Unit Test: FileNotFound

Add in in pom.xml give the following plugin:

<plugin>
  <artifactId>maven-surefire-plugin</artifactId>
  <version>2.10</version>
  <configuration>
    <useFile>false</useFile>
  </configuration>
</plugin>

Validate select box

<select id='bookcategory' class="form-control" required="">
                    <option value="" disabled="disabled">Category</option>
                    <option value="1">LITERATURE & FICTION</option>
                    <option value="2">NON FICTION</option>
                    <option value="3">ACADEMIC</option>
            <option value="4">CHILDREN & TEENS</option>

                </select>

HTML form validation can be performed automatically by the browser. Try the above code:
The rest all will be done automatically, no need to create any js functions just this dropdown and a submit button.

How to use ng-repeat without an html element

Update: If you are using Angular 1.2+, use ng-repeat-start. See @jmagnusson's answer.

Otherwise, how about putting the ng-repeat on tbody? (AFAIK, it is okay to have multiple <tbody>s in a single table.)

<tbody ng-repeat="row in array">
  <tr ng-repeat="item in row">
     <td>{{item}}</td>
  </tr>
</tbody>

Full path from file input using jQuery

Well, getting full path is not possible but we can have a temporary path.

Try This:

It'll give you a temporary path not the accurate path, you can use this script if you want to show selected images as in this jsfiddle example(Try it by selectng images as well as other files):-

JSFIDDLE

Here is the code :-

HTML:-

<input type="file" id="i_file" value=""> 
<input type="button" id="i_submit" value="Submit">
    <br>
<img src="" width="200" style="display:none;" />
        <br>
<div id="disp_tmp_path"></div>

JS:-

$('#i_file').change( function(event) {
var tmppath = URL.createObjectURL(event.target.files[0]);
    $("img").fadeIn("fast").attr('src',URL.createObjectURL(event.target.files[0]));

    $("#disp_tmp_path").html("Temporary Path(Copy it and try pasting it in browser address bar) --> <strong>["+tmppath+"]</strong>");
});

Its not exactly what you were looking for, but may be it can help you somewhere.

MySQL Trigger after update only if row has changed

As a workaround, you could use the timestamp (old and new) for checking though, that one is not updated when there are no changes to the row. (Possibly that is the source for confusion? Because that one is also called 'on update' but is not executed when no change occurs) Changes within one second will then not execute that part of the trigger, but in some cases that could be fine (like when you have an application that rejects fast changes anyway.)

For example, rather than

IF NEW.a <> OLD.a or NEW.b <> OLD.b /* etc, all the way to NEW.z <> OLD.z */ 
THEN  
  INSERT INTO bar (a, b) VALUES(NEW.a, NEW.b) ;
END IF

you could use

IF NEW.ts <> OLD.ts 
THEN  
  INSERT INTO bar (a, b) VALUES(NEW.a, NEW.b) ;
END IF

Then you don't have to change your trigger every time you update the scheme (the issue you mentioned in the question.)

EDIT: Added full example

create table foo (a INT, b INT, ts TIMESTAMP);
create table bar (a INT, b INT);

INSERT INTO foo (a,b) VALUES(1,1);
INSERT INTO foo (a,b) VALUES(2,2);
INSERT INTO foo (a,b) VALUES(3,3);

DELIMITER ///

CREATE TRIGGER ins_sum AFTER UPDATE ON foo
    FOR EACH ROW
    BEGIN
        IF NEW.ts <> OLD.ts THEN  
            INSERT INTO bar (a, b) VALUES(NEW.a, NEW.b);
        END IF;
    END;
///

DELIMITER ;

select * from foo;
+------+------+---------------------+
| a    | b    | ts                  |
+------+------+---------------------+
|    1 |    1 | 2011-06-14 09:29:46 |
|    2 |    2 | 2011-06-14 09:29:46 |
|    3 |    3 | 2011-06-14 09:29:46 |
+------+------+---------------------+
3 rows in set (0.00 sec)

-- UPDATE without change
UPDATE foo SET b = 3 WHERE a = 3;
Query OK, 0 rows affected (0.00 sec)
Rows matched: 1  Changed: 0  Warnings: 0

-- the timestamo didnt change
select * from foo WHERE a = 3;
+------+------+---------------------+
| a    | b    | ts                  |
+------+------+---------------------+
|    3 |    3 | 2011-06-14 09:29:46 |
+------+------+---------------------+
1 rows in set (0.00 sec)

-- the trigger didn't run
select * from bar;
Empty set (0.00 sec)

-- UPDATE with change
UPDATE foo SET b = 4 WHERE a=3;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

-- the timestamp changed
select * from foo;
+------+------+---------------------+
| a    | b    | ts                  |
+------+------+---------------------+
|    1 |    1 | 2011-06-14 09:29:46 |
|    2 |    2 | 2011-06-14 09:29:46 |
|    3 |    4 | 2011-06-14 09:34:59 |
+------+------+---------------------+
3 rows in set (0.00 sec)

-- and the trigger ran
select * from bar;
+------+------+---------------------+
| a    | b    | ts                  |
+------+------+---------------------+
|    3 |    4 | 2011-06-14 09:34:59 |
+------+------+---------------------+
1 row in set (0.00 sec)

It is working because of mysql's behavior on handling timestamps. The time stamp is only updated if a change occured in the updates.

Documentation is here:
https://dev.mysql.com/doc/refman/5.7/en/timestamp-initialization.html

desc foo;
+-------+-----------+------+-----+-------------------+-----------------------------+
| Field | Type      | Null | Key | Default           | Extra                       |
+-------+-----------+------+-----+-------------------+-----------------------------+
| a     | int(11)   | YES  |     | NULL              |                             |
| b     | int(11)   | YES  |     | NULL              |                             |
| ts    | timestamp | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
+-------+-----------+------+-----+-------------------+-----------------------------+

#1062 - Duplicate entry for key 'PRIMARY'

I solved it by changing the "lock" property from "shared" to "exclusive":

ALTER TABLE `table` 
CHANGE COLUMN `ID` `ID` INT(11) NOT NULL AUTO_INCREMENT COMMENT '' , LOCK = EXCLUSIVE;

RVM is not a function, selecting rubies with 'rvm use ...' will not work

Type bash --login from your terminal. And then give rvm use 2.0.0

Difference between 'cls' and 'self' in Python classes?

Instead of accepting a self parameter, class methods take a cls parameter that points to the class—and not the object instance—when the method is called. Since the class method only has access to this cls argument, it can’t modify object instance state. That would require access to self . However, class methods can still modify class state that applies across all instances of the class.

-Python Tricks

HTTP GET in VBS

Dim o
Set o = CreateObject("MSXML2.XMLHTTP")
o.open "GET", "http://www.example.com", False
o.send
' o.responseText now holds the response as a string.

jQuery selector first td of each row

$('td:first-child') will return a collection of the elements that you want.

var text = $('td:first-child').map(function() {
  return $(this).html();
}).get();

if condition in sql server update query

this worked great:

UPDATE
    table_Name
SET 
  column_A = CASE WHEN @flag = '1' THEN column_A + @new_value ELSE column_A END,
  column_B = CASE WHEN @flag = '0' THEN column_B + @new_value ELSE column_B END
WHERE
    ID = @ID

Is it possible to set transparency in CSS3 box-shadow?

I suppose rgba() would work here. After all, browser support for both box-shadow and rgba() is roughly the same.

/* 50% black box shadow */
box-shadow: 10px 10px 10px rgba(0, 0, 0, 0.5);

_x000D_
_x000D_
div {_x000D_
    width: 200px;_x000D_
    height: 50px;_x000D_
    line-height: 50px;_x000D_
    text-align: center;_x000D_
    color: white;_x000D_
    background-color: red;_x000D_
    margin: 10px;_x000D_
}_x000D_
_x000D_
div.a {_x000D_
  box-shadow: 10px 10px 10px #000;_x000D_
}_x000D_
_x000D_
div.b {_x000D_
  box-shadow: 10px 10px 10px rgba(0, 0, 0, 0.5);_x000D_
}
_x000D_
<div class="a">100% black shadow</div>_x000D_
<div class="b">50% black shadow</div>
_x000D_
_x000D_
_x000D_

python 2.7: cannot pip on windows "bash: pip: command not found"

On windows 7, you have to use this command: python -m pip install xxx. All above don't work for me.

What is a None value?

Martijn's answer explains what None is in Python, and correctly states that the book is misleading. Since Python programmers as a rule would never say

Assigning a value of None to a variable is one way to reset it to its original, empty state.

it's hard to explain what Briggs means in a way which makes sense and explains why no one here seems happy with it. One analogy which may help:

In Python, variable names are like stickers put on objects. Every sticker has a unique name written on it, and it can only be on one object at a time, but you could put more than one sticker on the same object, if you wanted to. When you write

F = "fork"

you put the sticker "F" on a string object "fork". If you then write

F = None

you move the sticker to the None object.

What Briggs is asking you to imagine is that you didn't write the sticker "F", there was already an F sticker on the None, and all you did was move it, from None to "fork". So when you type F = None, you're "reset[ting] it to its original, empty state", if we decided to treat None as meaning empty state.

I can see what he's getting at, but that's a bad way to look at it. If you start Python and type print(F), you see

>>> print(F)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'F' is not defined

and that NameError means Python doesn't recognize the name F, because there is no such sticker. If Briggs were right and F = None resets F to its original state, then it should be there now, and we should see

>>> print(F)
None

like we do after we type F = None and put the sticker on None.


So that's all that's going on. In reality, Python comes with some stickers already attached to objects (built-in names), but others you have to write yourself with lines like F = "fork" and A = 2 and c17 = 3.14, and then you can stick them on other objects later (like F = 10 or F = None; it's all the same.)

Briggs is pretending that all possible stickers you might want to write were already stuck to the None object.

window.location.href and window.open () methods in JavaScript

The window.open will open url in new browser Tab

The window.location.href will open url in current Tab (instead you can use location)

Here is example fiddle (in SO snippets window.open doesn't work)

_x000D_
_x000D_
var url = 'https://example.com';_x000D_
_x000D_
function go1() { window.open(url) }_x000D_
_x000D_
function go2() { window.location.href = url }_x000D_
_x000D_
function go3() { location = url }
_x000D_
<div>Go by:</div>_x000D_
<button onclick="go1()">window.open</button>_x000D_
<button onclick="go2()">window.location.href</button>_x000D_
<button onclick="go3()">location</button>
_x000D_
_x000D_
_x000D_

selecting rows with id from another table

You can use a subquery:

SELECT *
FROM terms
WHERE id IN (SELECT term_id FROM terms_relation WHERE taxonomy='categ');

and if you need to show all columns from both tables:

SELECT t.*, tr.*
FROM terms t, terms_relation tr
WHERE t.id = tr.term_id
AND tr.taxonomy='categ'

PHP Warning: Unknown: failed to open stream

It happened to me today with /home/user/public_html/index.php and the solution was to do chmod o+x /home/user as this directory has to have the X as otherwise the apache server can't list files (i.e. do ls)

What is the difference between require_relative and require in Ruby?

Just look at the docs:

require_relative complements the builtin method require by allowing you to load a file that is relative to the file containing the require_relative statement.

For example, if you have unit test classes in the "test" directory, and data for them under the test "test/data" directory, then you might use a line like this in a test case:

require_relative "data/customer_data_1"

How can I select all elements without a given class in jQuery?

if (!$(row).hasClass("changed")) {
    // do your stuff
}

How do I convert dmesg timestamp to custom date format?

Understanding dmesg timestamp is pretty simple: it is time in seconds since the kernel started. So, having time of startup (uptime), you can add up the seconds and show them in whatever format you like.

Or better, you could use the -T command line option of dmesg and parse the human readable format.

From the man page:

-T, --ctime
    Print human readable timestamps. The timestamp could be inaccurate!

    The time source used for the logs is not updated after system SUSPEND/RESUME.

Adding two Java 8 streams, or an extra element to a stream

Just do:

Stream.of(stream1, stream2, Stream.of(element)).flatMap(identity());

where identity() is a static import of Function.identity().

Concatenating multiple streams into one stream is the same as flattening a stream.

However, unfortunately, for some reason there is no flatten() method on Stream, so you have to use flatMap() with the identity function.

Android Emulator sdcard push error: Read-only file system

Ensure two things in the AVD manager utility for the emulator:

  1. SD Card size is mentioned e.g. 512.

  2. From the Hardware tag, press New and select "SD Card Support" from the drop down menu.

Now, start the emulator. SD Card shall now support writing as well.

What does the Excel range.Rows property really do?

Since the .Rows result is marked as consisting of rows, you can "For Each" it to deal with each row individually, like this:

Function Attendance(rng As Range) As Long
Attendance = 0
For Each rRow In rng.Rows
    If WorksheetFunction.Sum(rRow) > 0 Then
        Attendance = Attendance + 1
    End If
Next
End Function

I use this to check attendance in any of a few categories (different columns) for a list of people (different rows).

(And of course you could use .Columns to do a "For Each" over the columns in the range.)

C# - How to add an Excel Worksheet programmatically - Office XP / 2003

Another "Up Tick" for AR..., but if you don't have to use interop I would avoid it altogether. This product is actually quite interesting: http://www.clearoffice.com/ and it provides a very intuitive, fully managed, api for manipulation excel files and seems to be free. (at least for the time being) SpreadSheetGear is also excellent but pricey.

my two cents.

Bootstrap 4 img-circle class not working

In Bootstrap 4 it was renamed to .rounded-circle

Usage :

<div class="col-xs-7">
    <img src="img/gallery2.JPG" class="rounded-circle" alt="HelPic>
</div>

See migration docs from bootstrap.

When to use .First and when to use .FirstOrDefault with LINQ?

First:

  • Returns the first element of a sequence
  • Throws exception: There are no elements in the result
  • Use when: When more than 1 element is expected and you want only the first

FirstOrDefault:

  • Returns the first element of a sequence, or a default value if no element is found
  • Throws exception: Only if the source is null
  • Use when: When more than 1 element is expected and you want only the first. Also it is ok for the result to be empty

From: http://www.technicaloverload.com/linq-single-vs-singleordefault-vs-first-vs-firstordefault/

How can I force input to uppercase in an ASP.NET textbox?

<!-- Script by hscripts.com -->
<script language=javascript>
    function upper(ustr)
    {
        var str=ustr.value;
        ustr.value=str.toUpperCase();
    }

    function lower(ustr)
    {
        var str=ustr.value;
        ustr.value=str.toLowerCase();
    }
</script>

<form>
    Type Lower-case Letters<textarea name="address" onkeyup="upper(this)"></textarea>
</form>

<form>
    Type Upper-case Letters<textarea name="address" onkeyup="lower(this)"></textarea>
</form>

Pushing from local repository to GitHub hosted remote

You push your local repository to the remote repository using the git push command after first establishing a relationship between the two with the git remote add [alias] [url] command. If you visit your Github repository, it will show you the URL to use for pushing. You'll first enter something like:

git remote add origin [email protected]:username/reponame.git

Unless you started by running git clone against the remote repository, in which case this step has been done for you already.

And after that, you'll type:

git push origin master

After your first push, you can simply type:

git push

when you want to update the remote repository in the future.

Check whether a value exists in JSON object

This example puts your JSON into proper format and does an existence check. I use jquery for convenience.

http://jsfiddle.net/nXFxC/

<!-- HTML -->
<span id="test">Hello</span><br>
<span id="test2">Hello</span>

//Javascript

$(document).ready(function(){
    var JSON = {"animals":[{"name":"cat"}, {"name":"dog"}]};

if(JSON.animals[1].name){      
$("#test").html("It exists");
}
if(!JSON.animals[2]){       
$("#test2").html("It doesn't exist");
}
});

javascript cell number validation

<script type="text/javascript">
    function MobileNoValidation()
    {
       var phno=/^\d{10}$/
       if(textMobileNo.value=="")
       {
        alert("Mobile No Should Not Be Empty");
       }
       else if(!textMobileNo.value.match(phno))
       {
        alert("Mobile no must be ten digit");
       }
       else
       {
        alert("valid Mobile No");
       }
    }
</script>

Get value (String) of ArrayList<ArrayList<String>>(); in Java

Because the second element is null after you clear the list.

Use:

String s = myList.get(0);

And remember, index 0 is the first element.

SQL LEFT-JOIN on 2 fields for MySQL

select a.ip, a.os, a.hostname, a.port, a.protocol,
       b.state
from a
left join b on a.ip = b.ip 
           and a.port = b.port

PHP - cannot use a scalar as an array warning

Make sure that you don't declare it as a integer, float, string or boolean before. http://php.net/manual/en/function.is-scalar.php

Vertically centering Bootstrap modal window

My choice, just a little CSS: ( NOT working in IE8 )

.modal.fade .modal-dialog {
    transform: translate(-50%, -80%);
}

.modal.in .modal-dialog {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    margin-top: 0px;
}

You can play with the first rule to change how the modal appears.

Using: Bootstrap 3.3.4

how to check for null with a ng-if values in a view with angularjs?

Here is a simple example that I tried to explain.

<div>
    <div *ngIf="product">     <!--If "product" exists-->
      <h2>Product Details</h2><hr>
      <h4>Name: {{ product.name }}</h4>
      <h5>Price: {{ product.price | currency }}</h5>
      <p> Description: {{ product.description }}</p>
    </div>

    <div *ngIf="!product">     <!--If "product" not exists-->
       *Product not found
    </div>
</div>

Where does PHP store the error log? (php5, apache, fastcgi, cpanel)

On a LAMP environment the php errors are default directed to this below file.

/var/log/httpd/error_log

All access logs come under:

/var/log/httpd/access_log

How does the "this" keyword work?

A little bit info about this keyword

Let's log this keyword to the console in global scope without any more code but

console.log(this)

In Client/Browser this keyword is a global object which is window

console.log(this === window) // true

and

In Server/Node/Javascript runtime this keyword is also a global object which is module.exports

console.log(this === module.exports) // true
console.log(this === exports) // true

Keep in mind exports is just a reference to module.exports