Programs & Examples On #Boost spirit

Boost.Spirit is a set of C++ libraries for parsing and output generation implemented as Domain Specific Embedded Languages (DSEL) using Expression templates and Template Meta-Programming. The Spirit libraries enable a target grammar to be written exclusively in C++. Inline grammar specifications can mix freely with other C++ code and, thanks to the generative power of C++ templates, are immediately executable.

How to define an optional field in protobuf 3

To expand on @cybersnoopy 's suggestion here

if you had a .proto file with a message like so:

message Request {
    oneof option {
        int64 option_value = 1;
    }
}

You can make use of the case options provided (java generated code):

So we can now write some code as follows:

Request.OptionCase optionCase = request.getOptionCase();
OptionCase optionNotSet = OPTION_NOT_SET;

if (optionNotSet.equals(optionCase)){
    // value not set
} else {
    // value set
}

How to increase the clickable area of a <a> tag button?

Just make the anchor display: block and width/height: 100%. Eg:

.button a {
    display: block;
    width: 100%;
    height: 100%;
}

jsFiddle: http://jsfiddle.net/4mHTa/

Correct way to detach from a container without stopping it

The default way to detach from an interactive container is Ctrl+P Ctrl+Q, but you can override it when running a new container or attaching to existing container using the --detach-keys flag.

Using ChildActionOnly in MVC

FYI, [ChildActionOnly] is not available in ASP.NET MVC Core. see some info here

What is dtype('O'), in pandas?

'O' stands for object.

#Loading a csv file as a dataframe
import pandas as pd 
train_df = pd.read_csv('train.csv')
col_name = 'Name of Employee'

#Checking the datatype of column name
train_df[col_name].dtype

#Instead try printing the same thing
print train_df[col_name].dtype

The first line returns: dtype('O')

The line with the print statement returns the following: object

PHP cURL GET request and request's body

For those coming to this with similar problems, this request library allows you to make external http requests seemlessly within your php application. Simplified GET, POST, PATCH, DELETE and PUT requests.

A sample request would be as below

use Libraries\Request;

$data = [
  'samplekey' => 'value',
  'otherkey' => 'othervalue'
];

$headers = [
  'Content-Type' => 'application/json',
  'Content-Length' => sizeof($data)
];

$response = Request::post('https://example.com', $data, $headers);
// the $response variable contains response from the request

Documentation for the same can be found in the project's README.md

Create Log File in Powershell

A function that takes these principles a little further.

  1. Add's timestamps - can't have a log without timestamps.
  2. Add's a level (uses INFO by default) meaning you can highlight big issues.
  3. Allows for optional console output. If you don't set a log destination, it simply pumps it out.

    Function Write-Log {
        [CmdletBinding()]
        Param(
        [Parameter(Mandatory=$False)]
        [ValidateSet("INFO","WARN","ERROR","FATAL","DEBUG")]
        [String]
        $Level = "INFO",
    
        [Parameter(Mandatory=$True)]
        [string]
        $Message,
    
        [Parameter(Mandatory=$False)]
        [string]
        $logfile
        )
    
        $Stamp = (Get-Date).toString("yyyy/MM/dd HH:mm:ss")
        $Line = "$Stamp $Level $Message"
        If($logfile) {
            Add-Content $logfile -Value $Line
        }
        Else {
            Write-Output $Line
        }
    }
    

Convert LocalDate to LocalDateTime or java.sql.Timestamp

Since Joda is getting faded, someone might want to convert LocaltDate to LocalDateTime in Java 8. In Java 8 LocalDateTime it will give a way to create a LocalDateTime instance using a LocalDate and LocalTime. Check here.

public static LocalDateTime of(LocalDate date, LocalTime time)

Sample would be,

    // just to create a sample LocalDate
    DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyyMMdd");
    LocalDate ld = LocalDate.parse("20180306", dtf);

    // convert ld into a LocalDateTime
    // We need to specify the LocalTime component here as well, it can be any accepted value
    LocalDateTime ldt = LocalDateTime.of(ld, LocalTime.of(0,0)); // 2018-03-06T00:00

Just for reference, For getting the epoch seconds below can be used,

    ZoneId zoneId = ZoneId.systemDefault();
    long epoch = ldt.atZone(zoneId).toEpochSecond(); 

    // If you only care about UTC
    long epochUTC = ldt.toEpochSecond(ZoneOffset.UTC);

CSS transition effect makes image blurry / moves image 1px, in Chrome?

I had a similar problem with blurry text but only the succeeding div was affected. For some reason the next div after the one that I was doing the transform in was blurry.

I tried everything that is recommended in this thread but nothing worked. For me rearranging my divs worked. I moved the div that blurres the following div to the end of parents div.

If someone know why just let me know.

#before
<header class="container">
      <div class="transformed div">
          <span class="transform wrapper">
            <span class="transformed"></span>
            <span class="transformed"></span>
          </span>
       </div>
       <div class="affected div">
       </div>
     </header>

#after
<header class="container">
   <div class="affected div">
   </div>
  <div class="transformed div">
      <span class="transform wrapper">
        <span class="transformed"></span>
        <span class="transformed"></span>
      </span>
   </div>

 </header>

How to get value of selected radio button?

You can get the value by using the checked property.

var rates = document.getElementsByName('rate');
var rate_value;
for(var i = 0; i < rates.length; i++){
    if(rates[i].checked){
        rate_value = rates[i].value;
    }
}

Excel - programm cells to change colour based on another cell

  1. Select cell B3 and click the Conditional Formatting button in the ribbon and choose "New Rule".
  2. Select "Use a formula to determine which cells to format"
  3. Enter the formula: =IF(B2="X",IF(B3="Y", TRUE, FALSE),FALSE), and choose to fill green when this is true
  4. Create another rule and enter the formula =IF(B2="X",IF(B3="W", TRUE, FALSE),FALSE) and choose to fill red when this is true.

More details - conditional formatting with a formula applies the format when the formula evaluates to TRUE. You can use a compound IF formula to return true or false based on the values of any cells.

How do I extract the contents of an rpm?

The "DECOMPRESSION" test fails on CygWin, one of the most potentiaally useful platforms for it, due to the "grep" check for "xz" being case sensitive. The result of the "COMPRESSION:" check is:

COMPRESSION='/dev/stdin: XZ compressed data'

Simply replacing 'grep -q' with 'grep -q -i' everywhere seems to resolve the issue well.

I've done a few updates, particularly adding some comments and using "case" instead of stacked "if" statements, and included that fix below

#!/bin/sh
#
# rpm2cpio.sh - extract 'cpio' contents of RPM
#
# Typical usage: rpm2cpio.sh rpmname | cpio -idmv
#

if [ "$# -ne 1" ]; then
    echo "Usage: $0 file.rpm" 1>&2
    exit 1
fi

rpm="$1"
if [ -e "$rpm" ]; then
    echo "Error: missing $rpm"
fi


leadsize=96
o=`expr $leadsize + 8`
set `od -j $o -N 8 -t u1 $rpm`
il=`expr 256 \* \( 256 \* \( 256 \* $2 + $3 \) + $4 \) + $5`
dl=`expr 256 \* \( 256 \* \( 256 \* $6 + $7 \) + $8 \) + $9`
# echo "sig il: $il dl: $dl"

sigsize=`expr 8 + 16 \* $il + $dl`
o=`expr $o + $sigsize + \( 8 - \( $sigsize \% 8 \) \) \% 8 + 8`
set `od -j $o -N 8 -t u1 $rpm`
il=`expr 256 \* \( 256 \* \( 256 \* $2 + $3 \) + $4 \) + $5`
dl=`expr 256 \* \( 256 \* \( 256 \* $6 + $7 \) + $8 \) + $9`
# echo "hdr il: $il dl: $dl"

hdrsize=`expr 8 + 16 \* $il + $dl`
o=`expr $o + $hdrsize`
EXTRACTOR="dd if=$rpm ibs=$o skip=1"

COMPRESSION=`($EXTRACTOR |file -) 2>/dev/null`
DECOMPRESSOR="cat"

case $COMPRESSION in
    *gzip*|*GZIP*)
        DECOMPRESSOR=gunzip
        ;;
    *bzip2*|*BZIP2*)
        DECOMPRESSOR=bunzip2
        ;;
    *xz*|*XZ*)
        DECOMPRESSOR=unxz
        ;;
    *cpio*|*cpio*)
        ;;
    *)
        # Most versions of file don't support LZMA, therefore we assume
        # anything not detected is LZMA
        DECOMPRESSOR="`which unlzma 2>/dev/null`"
        case "$DECOMPRESSOR" in
            /*)
                DECOMPRESSOR="$DECOMPRESSOR"
                ;;
            *)
                DECOMPRESSOR=`which lzmash 2>/dev/null`
                case "$DECOMPRESSOR" in
                    /* )
                        DECOMPRESSOR="lzmash -d -c"
                        ;;
                    *  )
                        echo "Warning: DECOMPRESSOR not found, assuming 'cat'" 1>&2
                        ;;
                esac
                ;;
        esac
esac

$EXTRACTOR 2>/dev/null | $DECOMPRESSOR

How does MySQL CASE work?

CASE is more like a switch statement. It has two syntaxes you can use. The first lets you use any compare statements you want:

CASE 
    WHEN user_role = 'Manager' then 4
    WHEN user_name = 'Tom' then 27
    WHEN columnA <> columnB then 99
    ELSE -1 --unknown
END

The second style is for when you are only examining one value, and is a little more succinct:

CASE user_role
    WHEN 'Manager' then 4
    WHEN 'Part Time' then 7
    ELSE -1 --unknown
END

browser.msie error after update to jQuery 1.9.1

Since $.browser is deprecated, here is an alternative solution:

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

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

    return rv;
}

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

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

    alert( msg );
}

Source

However, the reason that its deprecated is because jQuery wants you to use feature detection instead.

An example:

$("p").html("This frame uses the W3C box model: <span>" +
        jQuery.support.boxModel + "</span>");

And last but not least, the most reliable way to check IE versions:

// ----------------------------------------------------------
// A short snippet for detecting versions of IE in JavaScript
// without resorting to user-agent sniffing
// ----------------------------------------------------------
// If you're not in IE (or IE version is less than 5) then:
//     ie === undefined
// If you're in IE (>=5) then you can determine which version:
//     ie === 7; // IE7
// Thus, to detect IE:
//     if (ie) {}
// And to detect the version:
//     ie === 6 // IE6
//     ie > 7 // IE8, IE9 ...
//     ie < 9 // Anything less than IE9
// ----------------------------------------------------------

// UPDATE: Now using Live NodeList idea from @jdalton

var ie = (function(){

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

    while (
        div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->',
        all[0]
    );

    return v > 4 ? v : undef;

}());

Java ResultSet how to check if there are any results

To be totally sure of rather the resultset is empty or not regardless of cursor position, I would do something like this:

public static boolean isMyResultSetEmpty(ResultSet rs) throws SQLException {
    return (!rs.isBeforeFirst() && rs.getRow() == 0);
}

This function will return true if ResultSet is empty, false if not or throw an SQLException if that ResultSet is closed/uninitialized.

Removing App ID from Developer Connection

Update: You can now remove an App ID (as noted by @Guru in the comments).

In the past, this was not possible: I had the same problem, and the folks at Apple replied that they will leave all of the App ID you create associated to your login, to keep track of a sort of history related to your login.

It seems that they finally changed idea about.

Split Java String by New Line

package in.javadomain;

public class JavaSplit {

    public static void main(String[] args) {
        String input = "chennai\nvellore\ncoimbatore\nbangalore\narcot";
        System.out.println("Before split:\n");
        System.out.println(input);

        String[] inputSplitNewLine = input.split("\\n");
        System.out.println("\n After split:\n");
        for(int i=0; i<inputSplitNewLine.length; i++){
            System.out.println(inputSplitNewLine[i]);
        }
    }

}

Should ol/ul be inside <p> or outside?

GO here http://validator.w3.org/ upload your html file and it will tell you what is valid and what is not.

Import Package Error - Cannot Convert between Unicode and Non Unicode String Data Type

Not sure if this is still a problem but I found this simple solution:

  1. Right-Click Ole DB Source
  2. Select 'Edit'
  3. Select Input and Output Properties Tab
  4. Under "Inputs and Outputs", Expand "Ole DB Source Output" External Columns and Output Columns
  5. In Output columns, select offending field, on the right-hand panel ensure Data Type Property matches that of the field in External Columns properties

Hope this was clear and easy to follow

How to extract a value from a string using regex and a shell?

Yes regex can certainly be used to extract part of a string. Unfortunately different flavours of *nix and different tools use slightly different Regex variants.

This sed command should work on most flavours (Tested on OS/X and Redhat)

echo '12 BBQ ,45 rofl, 89 lol' | sed  's/^.*,\([0-9][0-9]*\).*$/\1/g'

Comparing two dictionaries and checking how many (key, value) pairs are equal

Yet another possibility, up to the last note of the OP, is to compare the hashes (SHA or MD) of the dicts dumped as JSON. The way hashes are constructed guarantee that if they are equal, the source strings are equal as well. This is very fast and mathematically sound.

import json
import hashlib

def hash_dict(d):
    return hashlib.sha1(json.dumps(d, sort_keys=True)).hexdigest()

x = dict(a=1, b=2)
y = dict(a=2, b=2)
z = dict(a=1, b=2)

print(hash_dict(x) == hash_dict(y))
print(hash_dict(x) == hash_dict(z))

How to create EditText accepts Alphabets only in android?

For spaces, you can add single space in the digits. If you need any special characters like the dot, a comma also you can add to this list

android:digits="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ "

Searching for Text within Oracle Stored Procedures

I allways use UPPER(text) like UPPER('%blah%')

How to detect responsive breakpoints of Twitter Bootstrap 3 using JavaScript?

Since bootstrap 4 will be out soon I thought I would share a function that supports it (xl is now a thing) and performs minimal jQuery to get the job done.

/**
 * Get the Bootstrap device size
 * @returns {string|boolean} xs|sm|md|lg|xl on success, otherwise false if Bootstrap is not working or installed
 */
function findBootstrapEnvironment() {
    var environments = ['xs', 'sm', 'md', 'lg', 'xl'];
    var $el = $('<span />');
    $el.appendTo($('body'));
    for (var i = environments.length - 1; i >= 0; i--) {
        var env = environments[i];
        $el.addClass('hidden-'+env);
        if ($el.is(':hidden')) {
            $el.remove();
            return env;
        }
    }
    $el.remove();
    return false;
}

React - uncaught TypeError: Cannot read property 'setState' of undefined

Adding

onClick={this.delta.bind(this)}

will solve the problem . this error comes when we try to call the function of ES6 class , So we need to bind the method.

How to connect to Mysql Server inside VirtualBox Vagrant?

I came across this issue recently. I used PuPHPet to generate a config.

To connect to MySQL through SSH, the "vagrant" password was not working for me, instead I had to authenticate through the SSH key file.

To connect with MySQL Workbench

Connection method

Standard TCP/IP over SSH

SSH

Hostname: 127.0.0.1:2222 (forwarded SSH port)
Username: vagrant
Password: (do not use)
SSH Key File: C:\vagrantpath\puphpet\files\dot\ssh\insecure_private_key
              (Locate your insercure_private_key)

MySQL

Server Port: 3306
username: (root, or username)
password: (password)

Test the connection.

Mercurial undo last commit

Its workaround.

If you not push to server, you will clone into new folder else washout(delete all files) from your repository folder and clone new.

How does internationalization work in JavaScript?

Mozilla recently released the awesome L20n or localization 2.0. In their own words L20n is

an open source, localization-specific scripting language used to process gender, plurals, conjugations, and most of the other quirky elements of natural language.

Their js implementation is on the github L20n repository.

How do I test if a variable is a number in Bash?

I like Alberto Zaccagni's answer.

if [ "$var" -eq "$var" ] 2>/dev/null; then

Important prerequisites: - no subshells spawned - no RE parsers invoked - most shell applications don't use real numbers

But if $var is complex (e.g. an associative array access), and if the number will be a non-negative integer (most use-cases), then this is perhaps more efficient?

if [ "$var" -ge 0 ] 2> /dev/null; then ..

How to send POST request?

Your data dictionary conteines names of form input fields, you just keep on right their values to find results. form view Header configures browser to retrieve type of data you declare. With requests library it's easy to send POST:

import requests

url = "https://bugs.python.org"
data = {'@number': 12524, '@type': 'issue', '@action': 'show'}
headers = {"Content-type": "application/x-www-form-urlencoded", "Accept":"text/plain"}
response = requests.post(url, data=data, headers=headers)

print(response.text)

More about Request object: https://requests.readthedocs.io/en/master/api/

Reactive forms - disabled attribute

add disable="true" to html field Example :disable

<amexio-text-input formControlName="LastName" disable="true" [(ngModel)]="emplpoyeeRegistration.lastName" [field-label]="'Last Name'" [place-holder]="'Please enter last name'" [allow-blank]="true" [error-msg]="'errorMsg'" [enable-popover]="true" [min-length]="2"
[min-error-msg]="'Minimum 2 char allowed'" [max-error-msg]="'Maximum 20 char allowed'" name="xyz" [max-length]="20">
[icon-feedback]="true">
</amexio-text-input>

How do you parse and process HTML/XML in PHP?

Another option you can try is QueryPath. It's inspired by jQuery, but on the server in PHP and used in Drupal.

Can't pickle <type 'instancemethod'> when using multiprocessing Pool.map()

You could also define a __call__() method inside your someClass(), which calls someClass.go() and then pass an instance of someClass() to the pool. This object is pickleable and it works fine (for me)...

How to get past the login page with Wget?

I use this chrome extension. It'll give you the wget command for any download link you open.

Matplotlib: "Unknown projection '3d'" error

Try this:

import matplotlib.pyplot as plt
import seaborn as sns
from mpl_toolkits.mplot3d import axes3d

fig=plt.figure(figsize=(16,12.5))
ax=fig.add_subplot(2,2,1,projection="3d")

a=ax.scatter(Dataframe['bedrooms'],Dataframe['bathrooms'],Dataframe['floors'])
plt.plot(a)

What is the difference between '@' and '=' in directive scope in AngularJS?

Why do I have to use "{{title}}" with '@' and "title" with '='?

When you use {{title}} , only the parent scope value will be passed to directive view and evaluated. This is limited to one way, meaning that change will not be reflected in parent scope. You can use '=' when you want to reflect the changes done in child directive to parent scope also. This is two way.

Can I also access the parent scope directly, without decorating my element with an attribute?

When directive has scope attribute in it ( scope : {} ), then you no longer will be able to access parent scope directly. But still it is possible to access it via scope.$parent etc. If you remove scope from directive, it can be accessed directly.

The documentation says "Often it's desirable to pass data from the isolated scope via an expression and to the parent scope", but that seems to work fine with bidirectional binding too. Why would the expression route be better?

It depends based on context. If you want to call an expression or function with data, you use & and if you want share data , you can use biderectional way using '='

You can find the differences between multiple ways of passing data to directive at below link:

AngularJS – Isolated Scopes – @ vs = vs &

http://www.codeforeach.com/angularjs/angularjs-isolated-scopes-vs-vs

Remove part of string after "."

If the string should be of fixed length, then substr from base R can be used. But, we can get the position of the . with regexpr and use that in substr

substr(a, 1, regexpr("\\.", a)-1)
#[1] "NM_020506"    "NM_020519"    "NM_001030297" "NM_010281"    "NM_011419"    "NM_053155"   

Add a CSS border on hover without moving the element

Add a border to the regular item, the same color as the background, so that it cannot be seen. That way the item has a border: 1px whether it is being hovered or not.

Using sed and grep/egrep to search and replace

Use this command:

egrep -lRZ "\.jpg|\.png|\.gif" . \
    | xargs -0 -l sed -i -e 's/\.jpg\|\.gif\|\.png/.bmp/g'
  • egrep: find matching lines using extended regular expressions

    • -l: only list matching filenames

    • -R: search recursively through all given directories

    • -Z: use \0 as record separator

    • "\.jpg|\.png|\.gif": match one of the strings ".jpg", ".gif" or ".png"

    • .: start the search in the current directory

  • xargs: execute a command with the stdin as argument

    • -0: use \0 as record separator. This is important to match the -Z of egrep and to avoid being fooled by spaces and newlines in input filenames.

    • -l: use one line per command as parameter

  • sed: the stream editor

    • -i: replace the input file with the output without making a backup

    • -e: use the following argument as expression

    • 's/\.jpg\|\.gif\|\.png/.bmp/g': replace all occurrences of the strings ".jpg", ".gif" or ".png" with ".bmp"

Good Java graph algorithm library?

check out Blueprints:

Blueprints is a collection of interfaces, implementations, ouplementations, and test suites for the property graph data model. Blueprints is analogous to the JDBC, but for graph databases. Within the TinkerPop open source software stack, Blueprints serves as the foundational technology for:

Pipes: A lazy, data flow framework

Gremlin: A graph traversal language

Frames: An object-to-graph mapper

Furnace: A graph algorithms package

Rexster: A graph server

Get and Set Screen Resolution

Answer from different solutions to get Display Resolution

  1. Get the scaling factor

  2. Get Screen.PrimaryScreen.Bounds.Width and Screen.PrimaryScreen.Bounds.Height multiple by scaling factor result

    #region Display Resolution
    
     [DllImport("gdi32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
     public static extern int GetDeviceCaps(IntPtr hDC, int nIndex);
    
     public enum DeviceCap
     {
         VERTRES = 10,
         DESKTOPVERTRES = 117
     }
    
    
     public static double GetWindowsScreenScalingFactor(bool percentage = true)
     {
         //Create Graphics object from the current windows handle
         Graphics GraphicsObject = Graphics.FromHwnd(IntPtr.Zero);
         //Get Handle to the device context associated with this Graphics object
         IntPtr DeviceContextHandle = GraphicsObject.GetHdc();
         //Call GetDeviceCaps with the Handle to retrieve the Screen Height
         int LogicalScreenHeight = GetDeviceCaps(DeviceContextHandle, (int)DeviceCap.VERTRES);
         int PhysicalScreenHeight = GetDeviceCaps(DeviceContextHandle, (int)DeviceCap.DESKTOPVERTRES);
         //Divide the Screen Heights to get the scaling factor and round it to two decimals
         double ScreenScalingFactor = Math.Round(PhysicalScreenHeight / (double)LogicalScreenHeight, 2);
         //If requested as percentage - convert it
         if (percentage)
         {
             ScreenScalingFactor *= 100.0;
         }
         //Release the Handle and Dispose of the GraphicsObject object
         GraphicsObject.ReleaseHdc(DeviceContextHandle);
         GraphicsObject.Dispose();
         //Return the Scaling Factor
         return ScreenScalingFactor;
     }
    
     public static Size GetDisplayResolution()
     {
         var sf = GetWindowsScreenScalingFactor(false);
         var screenWidth = Screen.PrimaryScreen.Bounds.Width * sf;
         var screenHeight = Screen.PrimaryScreen.Bounds.Height * sf;
         return new Size((int)screenWidth, (int)screenHeight);
     }
    
     #endregion
    

to check display resolution

var size = GetDisplayResolution();
Console.WriteLine("Display Resoluton: " + size.Width + "x" + size.Height);

How to use onClick() or onSelect() on option tag in a JSP page?

In my case:

<html>
 <head>
  <script type="text/javascript">

    function changeFunction(val) {

       //Show option value
       console.log(val.value);
    }

  </script>
 </head>
 <body>
   <select id="selectBox" onchange="changeFunction(this)">
     <option value="1">Option #1</option>
     <option value="2">Option #2</option>
   </select>
 </body>
</html>

Customize list item bullets using CSS

You have to use an image to change the actual size or form of the bullet itself:

You can use a background image with appropriate padding to nudge content so it doesn't overlap:

list-style-image:url(bigger.gif);

or

background-image: url(images/bullet.gif);

Keyword not supported: "data source" initializing Entity Framework Context

This appears to be missing the providerName="System.Data.EntityClient" bit. Sure you got the whole thing?

How to get the name of a class without the package?

Class.getSimpleName()

Returns the simple name of the underlying class as given in the source code. Returns an empty string if the underlying class is anonymous.

The simple name of an array is the simple name of the component type with "[]" appended. In particular the simple name of an array whose component type is anonymous is "[]".

It is actually stripping the package information from the name, but this is hidden from you.

"break;" out of "if" statement?

break interacts solely with the closest enclosing loop or switch, whether it be a for, while or do .. while type. It is frequently referred to as a goto in disguise, as all loops in C can in fact be transformed into a set of conditional gotos:

for (A; B; C) D;
// translates to
A;
goto test;
loop: D;
iter: C;
test: if (B) goto loop;
end:

while (B) D;          // Simply doesn't have A or C
do { D; } while (B);  // Omits initial goto test
continue;             // goto iter;
break;                // goto end;

The difference is, continue and break interact with virtual labels automatically placed by the compiler. This is similar to what return does as you know it will always jump ahead in the program flow. Switches are slightly more complicated, generating arrays of labels and computed gotos, but the way break works with them is similar.

The programming error the notice refers to is misunderstanding break as interacting with an enclosing block rather than an enclosing loop. Consider:

for (A; B; C) {
   D;
   if (E) {
       F;
       if (G) break;   // Incorrectly assumed to break if(E), breaks for()
       H;
   }
   I;
}
J;

Someone thought, given such a piece of code, that G would cause a jump to I, but it jumps to J. The intended function would use if (!G) H; instead.

Number of processors/cores in command line

This is for those who want to a portable way to count cpu cores on *bsd, *nix or solaris (haven't tested on aix and hp-ux but should work). It has always worked for me.

dmesg | \
egrep 'cpu[. ]?[0-9]+' | \
sed 's/^.*\(cpu[. ]*[0-9]*\).*$/\1/g' | \
sort -u | \
wc -l | \
tr -d ' '

solaris grep & egrep don't have -o option so sed is used instead.

How can I fix MySQL error #1064?

TL;DR

Error #1064 means that MySQL can't understand your command. To fix it:

  • Read the error message. It tells you exactly where in your command MySQL got confused.

  • Examine your command. If you use a programming language to create your command, use echo, console.log(), or its equivalent to show the entire command so you can see it.

  • Check the manual. By comparing against what MySQL expected at that point, the problem is often obvious.

  • Check for reserved words. If the error occurred on an object identifier, check that it isn't a reserved word (and, if it is, ensure that it's properly quoted).

  1. Aaaagh!! What does #1064 mean?

    Error messages may look like gobbledygook, but they're (often) incredibly informative and provide sufficient detail to pinpoint what went wrong. By understanding exactly what MySQL is telling you, you can arm yourself to fix any problem of this sort in the future.

    As in many programs, MySQL errors are coded according to the type of problem that occurred. Error #1064 is a syntax error.

    • What is this "syntax" of which you speak? Is it witchcraft?

      Whilst "syntax" is a word that many programmers only encounter in the context of computers, it is in fact borrowed from wider linguistics. It refers to sentence structure: i.e. the rules of grammar; or, in other words, the rules that define what constitutes a valid sentence within the language.

      For example, the following English sentence contains a syntax error (because the indefinite article "a" must always precede a noun):

      This sentence contains syntax error a.

    • What does that have to do with MySQL?

      Whenever one issues a command to a computer, one of the very first things that it must do is "parse" that command in order to make sense of it. A "syntax error" means that the parser is unable to understand what is being asked because it does not constitute a valid command within the language: in other words, the command violates the grammar of the programming language.

      It's important to note that the computer must understand the command before it can do anything with it. Because there is a syntax error, MySQL has no idea what one is after and therefore gives up before it even looks at the database and therefore the schema or table contents are not relevant.

  2. How do I fix it?

    Obviously, one needs to determine how it is that the command violates MySQL's grammar. This may sound pretty impenetrable, but MySQL is trying really hard to help us here. All we need to do is…

    • Read the message!

      MySQL not only tells us exactly where the parser encountered the syntax error, but also makes a suggestion for fixing it. For example, consider the following SQL command:

      UPDATE my_table WHERE id=101 SET name='foo'
      

      That command yields the following error message:

      ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE id=101 SET name='foo'' at line 1

      MySQL is telling us that everything seemed fine up to the word WHERE, but then a problem was encountered. In other words, it wasn't expecting to encounter WHERE at that point.

      Messages that say ...near '' at line... simply mean that the end of command was encountered unexpectedly: that is, something else should appear before the command ends.

    • Examine the actual text of your command!

      Programmers often create SQL commands using a programming language. For example a php program might have a (wrong) line like this:

      $result = $mysqli->query("UPDATE " . $tablename ."SET name='foo' WHERE id=101");
      

      If you write this this in two lines

      $query = "UPDATE " . $tablename ."SET name='foo' WHERE id=101"
      $result = $mysqli->query($query);
      

      then you can add echo $query; or var_dump($query) to see that the query actually says

      UPDATE userSET name='foo' WHERE id=101
      

      Often you'll see your error immediately and be able to fix it.

    • Obey orders!

      MySQL is also recommending that we "check the manual that corresponds to our MySQL version for the right syntax to use". Let's do that.

      I'm using MySQL v5.6, so I'll turn to that version's manual entry for an UPDATE command. The very first thing on the page is the command's grammar (this is true for every command):

      UPDATE [LOW_PRIORITY] [IGNORE] table_reference
          SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ...
          [WHERE where_condition]
          [ORDER BY ...]
          [LIMIT row_count]
      

      The manual explains how to interpret this syntax under Typographical and Syntax Conventions, but for our purposes it's enough to recognise that: clauses contained within square brackets [ and ] are optional; vertical bars | indicate alternatives; and ellipses ... denote either an omission for brevity, or that the preceding clause may be repeated.

      We already know that the parser believed everything in our command was okay prior to the WHERE keyword, or in other words up to and including the table reference. Looking at the grammar, we see that table_reference must be followed by the SET keyword: whereas in our command it was actually followed by the WHERE keyword. This explains why the parser reports that a problem was encountered at that point.

    A note of reservation

    Of course, this was a simple example. However, by following the two steps outlined above (i.e. observing exactly where in the command the parser found the grammar to be violated and comparing against the manual's description of what was expected at that point), virtually every syntax error can be readily identified.

    I say "virtually all", because there's a small class of problems that aren't quite so easy to spot—and that is where the parser believes that the language element encountered means one thing whereas you intend it to mean another. Take the following example:

    UPDATE my_table SET where='foo'
    

    Again, the parser does not expect to encounter WHERE at this point and so will raise a similar syntax error—but you hadn't intended for that where to be an SQL keyword: you had intended for it to identify a column for updating! However, as documented under Schema Object Names:

    If an identifier contains special characters or is a reserved word, you must quote it whenever you refer to it. (Exception: A reserved word that follows a period in a qualified name must be an identifier, so it need not be quoted.) Reserved words are listed at Section 9.3, “Keywords and Reserved Words”.

    [ deletia ]

    The identifier quote character is the backtick (“`”):

    mysql> SELECT * FROM `select` WHERE `select`.id > 100;

    If the ANSI_QUOTES SQL mode is enabled, it is also permissible to quote identifiers within double quotation marks:

    mysql> CREATE TABLE "test" (col INT);
    ERROR 1064: You have an error in your SQL syntax...
    mysql> SET sql_mode='ANSI_QUOTES';
    mysql> CREATE TABLE "test" (col INT);
    Query OK, 0 rows affected (0.00 sec)

How to animate a View with Translate Animation in Android

In order to move a View anywhere on the screen, I would recommend placing it in a full screen layout. By doing so, you won't have to worry about clippings or relative coordinates.

You can try this sample code:

main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" android:id="@+id/rootLayout">

    <Button
        android:id="@+id/btn1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="MOVE" android:layout_centerHorizontal="true"/>

    <ImageView
        android:id="@+id/img1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher" android:layout_marginLeft="10dip"/>
    <ImageView
        android:id="@+id/img2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher" android:layout_centerVertical="true" android:layout_alignParentRight="true"/>
    <ImageView
        android:id="@+id/img3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher" android:layout_marginLeft="60dip" android:layout_alignParentBottom="true" android:layout_marginBottom="100dip"/>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical" android:clipChildren="false" android:clipToPadding="false">

        <ImageView
            android:id="@+id/img4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/ic_launcher" android:layout_marginLeft="60dip" android:layout_marginTop="150dip"/>
    </LinearLayout>

</RelativeLayout>

Your activity

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    ((Button) findViewById( R.id.btn1 )).setOnClickListener( new OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            ImageView img = (ImageView) findViewById( R.id.img1 );              
            moveViewToScreenCenter( img );
            img = (ImageView) findViewById( R.id.img2 );
            moveViewToScreenCenter( img );
            img = (ImageView) findViewById( R.id.img3 );                
            moveViewToScreenCenter( img );
            img = (ImageView) findViewById( R.id.img4 );
            moveViewToScreenCenter( img );
        }
    });
}

private void moveViewToScreenCenter( View view )
{
    RelativeLayout root = (RelativeLayout) findViewById( R.id.rootLayout );
    DisplayMetrics dm = new DisplayMetrics();
    this.getWindowManager().getDefaultDisplay().getMetrics( dm );
    int statusBarOffset = dm.heightPixels - root.getMeasuredHeight();

    int originalPos[] = new int[2];
    view.getLocationOnScreen( originalPos );

    int xDest = dm.widthPixels/2;
    xDest -= (view.getMeasuredWidth()/2);
    int yDest = dm.heightPixels/2 - (view.getMeasuredHeight()/2) - statusBarOffset;

    TranslateAnimation anim = new TranslateAnimation( 0, xDest - originalPos[0] , 0, yDest - originalPos[1] );
    anim.setDuration(1000);
    anim.setFillAfter( true );
    view.startAnimation(anim);
}

The method moveViewToScreenCenter gets the View's absolute coordinates and calculates how much distance has to move from its current position to reach the center of the screen. The statusBarOffset variable measures the status bar height.

I hope you can keep going with this example. Remember that after the animation your view's position is still the initial one. If you tap the MOVE button again and again the same movement will repeat. If you want to change your view's position do it after the animation is finished.

How to include a class in PHP

You can use either of the following:

include "class.twitter.php";

or

require "class.twitter.php";

Using require (or require_once if you want to ensure the class is only loaded once during execution) will cause a fatal error to be raised if the file doesn't exist, whereas include will only raise a warning. See http://php.net/require and http://php.net/include for more details

How to insert programmatically a new line in an Excel cell in C#?

What worked for me:

worksheet.Cells[0, 0].Style.WrapText = true;
worksheet.Cells[0, 0].Value = yourStringValue.Replace("\\r\\n", "\r\n");

My issue was that the \r\n came escaped.

How to show Bootstrap table with sort icon

BOOTSTRAP 4

you can use a combination of

  • fa-chevron-down, fa-chevron-up

  • fa-sort-down, fa-sort-up

<th class="text-center">
    <div class="btn-group" role="group">
        <button type="button" class="btn btn-xs btn-link py-0 pl-0 pr-1">
             Some Text OR icon
        </button>
        <div class="btn-group-vertical">
            <a href="?sort=asc" class="btn btn-xs btn-link p-0">
                <i class="fas fa-sort-up"></i>
            </a>
            <a href="?sort=desc" class="btn btn-xs btn-link p-0">
                <i class="fas fa-sort-down"></i>
            </a>
        </div>
    </div>
</th>

Does calling clone() on an array also clone its contents?

1D array of primitives does copy elements when it is cloned. This tempts us to clone 2D array(Array of Arrays).

Remember that 2D array clone doesn't work due to shallow copy implementation of clone().

public static void main(String[] args) {
    int row1[] = {0,1,2,3};
    int row2[] =  row1.clone();
    row2[0] = 10;
    System.out.println(row1[0] == row2[0]); // prints false

    int table1[][]={{0,1,2,3},{11,12,13,14}};
    int table2[][] = table1.clone();
    table2[0][0] = 100;
    System.out.println(table1[0][0] == table2[0][0]); //prints true
}

Return Boolean Value on SQL Select Statement

I do it like this:

SELECT 1 FROM [dbo].[User] WHERE UserID = 20070022

Seeing as a boolean can never be null (at least in .NET), it should default to false or you can set it to that yourself if it's defaulting true. However 1 = true, so null = false, and no extra syntax.

Note: I use Dapper as my micro orm, I'd imagine ADO should work the same.

Using Page_Load and Page_PreRender in ASP.Net

Processing the ASP.NET web-form takes place in stages. At each state various events are raised. If you are interested to plug your code into the processing flow (on server side) then you have to handle appropriate page event.

JQuery Error: cannot call methods on dialog prior to initialization; attempted to call method 'close'

You may want to declare the button content outside of the dialog, this works for me.

var closeFunction = function() {
    $(#dialog).dialog( "close" );
};

$('#dialog').dialog({
    modal: true,
    buttons: {
        Ok: closeFunction
    }
});

How do I round a double to two decimal places in Java?

First declare a object of DecimalFormat class. Note the argument inside the DecimalFormat is #.00 which means exactly 2 decimal places of rounding off.

private static DecimalFormat df2 = new DecimalFormat("#.00");

Now, apply the format to your double value:

double input = 32.123456;
System.out.println("double : " + df2.format(input)); // Output: 32.12

Note in case of double input = 32.1;

Then the output would be 32.10 and so on.

Convert JS date time to MySQL datetime

Full workaround (to mantain the timezone) using @Gajus answer concept:

var d = new Date(),
    finalDate = d.toISOString().split('T')[0]+' '+d.toTimeString().split(' ')[0];
console.log(finalDate); //2018-09-28 16:19:34 --example output

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.

Generating UNIQUE Random Numbers within a range

You can try next code:

function unique_randoms($min, $max, $count) {

 $arr = array();
 while(count($arr) < $count){
      $tmp =mt_rand($min,$max);
      if(!in_array($tmp, $arr)){
         $arr[] = $tmp;
      }
 }
return $arr;
}

Removing double quotes from a string in Java

You can just go for String replace method.-

line1 = line1.replace("\"", "");

Getting the current date in SQL Server?

SELECT CAST(GETDATE() AS DATE)

Returns the current date with the time part removed.

DATETIMEs are not "stored in the following format". They are stored in a binary format.

SELECT CAST(GETDATE() AS BINARY(8))

The display format in the question is independent of storage.

Formatting into a particular display format should be done by your application.

How to scroll to bottom in a ScrollView on activity startup

Put the following code after your data is added:

final ScrollView scrollview = ((ScrollView) findViewById(R.id.scrollview));
scrollview.post(new Runnable() {
    @Override
    public void run() {
        scrollview.fullScroll(ScrollView.FOCUS_DOWN);
    }
});

Find which version of package is installed with pip

The easiest way is this:

import jinja2
print jinja2.__version__

Global variables in header file

There are 3 scenarios, you describe:

  1. with 2 .c files and with int i; in the header.
  2. With 2 .c files and with int i=100; in the header (or any other value; that doesn't matter).
  3. With 1 .c file and with int i=100; in the header.

In each scenario, imagine the contents of the header file inserted into the .c file and this .c file compiled into a .o file and then these linked together.

Then following happens:

  1. works fine because of the already mentioned "tentative definitions": every .o file contains one of them, so the linker says "ok".

  2. doesn't work, because both .o files contain a definition with a value, which collide (even if they have the same value) - there may be only one with any given name in all .o files which are linked together at a given time.

  3. works of course, because you have only one .o file and so no possibility for collision.

IMHO a clean thing would be

  • to put either extern int i; or just int i; into the header file,
  • and then to put the "real" definition of i (namely int i = 100;) into file1.c. In this case, this initialization gets used at the start of the program and the corresponding line in main() can be omitted. (Besides, I hope the naming is only an example; please don't name any global variables as i in real programs.)

SQL join: selecting the last records in a one-to-many relationship

If you're using PostgreSQL you can use DISTINCT ON to find the first row in a group.

SELECT customer.*, purchase.*
FROM customer
JOIN (
   SELECT DISTINCT ON (customer_id) *
   FROM purchase
   ORDER BY customer_id, date DESC
) purchase ON purchase.customer_id = customer.id

PostgreSQL Docs - Distinct On

Note that the DISTINCT ON field(s) -- here customer_id -- must match the left most field(s) in the ORDER BY clause.

Caveat: This is a nonstandard clause.

How to create batch file in Windows using "start" with a path and command with spaces

Surrounding the path and the argument with spaces inside quotes as in your example should do. The command may need to handle the quotes when the parameters are passed to it, but it usually is not a big deal.

what's the default value of char?

'\u0000' is the default value for a character. Its decimal equivalent is 0.

When you are declaring some char variable without initializing it, '\u0000' will be assigned to it by default.

see this code

public class Test {
    char c;

    public static void main(String args[]) throws Exception {
        Test t = new Test();
        char c1 = '\u0000';
        System.out.println(t.c);
        System.out.println(c1);
        System.out.println(t.c == c1);
    }
}

This code will print true for the last print.

Making text background transparent but not text itself

If you use RGBA for modern browsers you don't need let older IEs use only the non-transparent version of the given color with RGB.

If you don't stick to CSS-only solutions, give CSS3PIE a try. With this syntax you can see exactly the same result in older IEs that you see in modern browsers:

div {
    -pie-background: rgba(223,231,233,0.8);
    behavior: url(../PIE.htc);
}

Chrome javascript debugger breakpoints don't do anything?

I'll add yet another random answer just because this question came up in response to my several searches. I have jQuery objects that have public and private methods. The pattern is:

myObject = (function($){
  function publicFunction() {}
  function privateFunction() {}
  return {
    theOnlyMethod: publicFunction
  }
})(jQuery);

If I put a breakpoint on a line inside a private function, Chrome will not debug it, the line moves down to the return statement! So to debug, I have to expose the private functions! This is new to me this morning (8/20/2020, Version 84.0.4147.125 (Official Build) (64-bit)), I can't believe I've not run into this in 3 years.

MySQL selecting yesterday's date

I adapted one of the above answers from cdhowie as I could not get it to work. This seems to work for me. I suspect it's also possible to do this with the UNIX_TIMESTAMP function been used.

SELECT * FROM your_table

WHERE UNIX_TIMESTAMP(DateVisited) >= UNIX_TIMESTAMP(CAST(NOW() - INTERVAL 1 DAY AS DATE))
  AND UNIX_TIMESTAMP(DateVisited) <= UNIX_TIMESTAMP(CAST(NOW() AS DATE));

How can I import Swift code to Objective-C?

Importing Swift file inside Objective-c can cause this error, if it doesn't import properly.

NOTE: You don't have to import Swift files externally, you just have to import one file which takes care of swift files.

When you Created/Copied Swift file inside Objective-C project. It would've created a bridging header automatically.

Check Objective-C Generated Interface Header Name at Targets -> Build Settings.

enter image description here

Based on above, I will import KJExpandable-Swift.h as it is.

Your's will be TargetName-Swift.h, Where TargetName differs based on your project name or another target your might have added and running on it.

As below my target is KJExpandable, so it's KJExpandable-Swift.h
enter image description here

Why does Git tell me "No such remote 'origin'" when I try to push to origin?

The following simple steps help me:

First, initialize the repository to work with Git, so that any file changes are tracked:

git init

Then, check that the remote repository that you want to associate with the alias origin exists, if not create it in git first.

$ git ls-remote https://github.com/repo-owner/repo-name.git/

If it exists, associate it with the remote "origin":

git remote add origin https://github.com:/repo-owner/repo-name.git

and check to which URL, the remote "origin" belongs to by using git remote -v:

$ git remote -v
origin  https://github.com:/repo-owner/repo-name.git (fetch)
origin  https://github.com:/repo-owner/repo-name.git (push)

Next, verify if your origin is properly aliased as follows:

$ cat ./.git/config
:
[remote "origin"]
        url = https://github.com:/repo-owner/repo-name.git
        fetch = +refs/heads/*:refs/remotes/origin/*
:

You need to see this section [remote "origin"]. You can consider to use GitHub Desktop available for both Windows and MacOS, which help me to automatically populate the missing section/s in ~./git/config file OR you can manually add it, not great, but hey it works!

[Optional]
You might also want to change the origin alias to make it more intuitive, especially if you are working with multiple origin:

git remote rename origin mynewalias

or even remove it:

git remote rm origin

Finally, on your first push, if you want master in that repository to be your default upstream. you may want to add the -u parameter

git add .
git commit -m 'First commit'
git push -u origin master

SQL Query NOT Between Two Dates

Do you mean that the date range of the selected rows should not lie fully within the specified date range? In which case:

select *
from test_table
where start_date < date '2009-12-15'
or end_date > date '2010-01-02';

(Syntax above is for Oracle, yours may differ slightly).

Java reflection: how to get field value from an object, not knowing its class

public abstract class Refl {
    /** Use: Refl.<TargetClass>get(myObject,"x.y[0].z"); */
    public static<T> T get(Object obj, String fieldPath) {
        return (T) getValue(obj, fieldPath);
    }
    public static Object getValue(Object obj, String fieldPath) {
        String[] fieldNames = fieldPath.split("[\\.\\[\\]]");
        String success = "";
        Object res = obj;
        for (String fieldName : fieldNames) {
            if (fieldName.isEmpty()) continue;
            int index = toIndex(fieldName);
            if (index >= 0) {
                try {
                    res = ((Object[])res)[index];
                } catch (ClassCastException cce) {
                    throw new RuntimeException("cannot cast "+res.getClass()+" object "+res+" to array, path:"+success, cce);
                } catch (IndexOutOfBoundsException iobe) {
                    throw new RuntimeException("bad index "+index+", array size "+((Object[])res).length +" object "+res +", path:"+success, iobe);
                }
            } else {
                Field field = getField(res.getClass(), fieldName);
                field.setAccessible(true);
                try {
                    res = field.get(res);
                } catch (Exception ee) {
                    throw new RuntimeException("cannot get value of ["+fieldName+"] from "+res.getClass()+" object "+res +", path:"+success, ee);
                }
            }
            success += fieldName + ".";
        }
        return res;
    }

    public static Field getField(Class<?> clazz, String fieldName) {
        Class<?> tmpClass = clazz;
        do {
            try {
                Field f = tmpClass.getDeclaredField(fieldName);
                return f;
            } catch (NoSuchFieldException e) {
                tmpClass = tmpClass.getSuperclass();
            }
        } while (tmpClass != null);

        throw new RuntimeException("Field '" + fieldName + "' not found in class " + clazz);
    }

    private static int toIndex(String s) {
        int res = -1;
        if (s != null && s.length() > 0 && Character.isDigit(s.charAt(0))) {
            try {
                res = Integer.parseInt(s);
                if (res < 0) {
                    res = -1;
                }
            } catch (Throwable t) {
                res = -1;
            }
        }
        return res;
    }
}

It supports fetching fields and array items, e.g.:

System.out.println(""+Refl.getValue(b,"x.q[0].z.y"));

there is no difference between dots and braces, they are just delimiters, and empty field names are ignored:

System.out.println(""+Refl.getValue(b,"x.q[0].z.y[value]"));
System.out.println(""+Refl.getValue(b,"x.q.1.y.z.value"));
System.out.println(""+Refl.getValue(b,"x[q.1]y]z[value"));

Nested classes' scope?

In Python mutable objects are passed as reference, so you can pass a reference of the outer class to the inner class.

class OuterClass:
    def __init__(self):
        self.outer_var = 1
        self.inner_class = OuterClass.InnerClass(self)
        print('Inner variable in OuterClass = %d' % self.inner_class.inner_var)

    class InnerClass:
        def __init__(self, outer_class):
            self.outer_class = outer_class
            self.inner_var = 2
            print('Outer variable in InnerClass = %d' % self.outer_class.outer_var)

How to dump only specific tables from MySQL?

Usage: mysqldump [OPTIONS] database [tables]

i.e.

mysqldump -u username -p db_name table1_name table2_name table3_name > dump.sql

Pandas split DataFrame by column value

Using "groupby" and list comprehension:

Storing all the split dataframe in list variable and accessing each of the seprated dataframe by their index.

DF = pd.DataFrame({'chr':["chr3","chr3","chr7","chr6","chr1"],'pos':[10,20,30,40,50],})
ans = [pd.DataFrame(y) for x, y in DF.groupby('chr', as_index=False)]

accessing the separated DF like this:

ans[0]
ans[1]
ans[len(ans)-1] # this is the last separated DF

accessing the column value of the separated DF like this:

ansI_chr=ans[i].chr 

Path to MSBuild

This works for Visual Studio 2015 and 2017:

function Get-MSBuild-Path {

    $vs14key = "HKLM:\SOFTWARE\Microsoft\MSBuild\ToolsVersions\14.0"
    $vs15key = "HKLM:\SOFTWARE\wow6432node\Microsoft\VisualStudio\SxS\VS7"

    $msbuildPath = ""

    if (Test-Path $vs14key) {
        $key = Get-ItemProperty $vs14key
        $subkey = $key.MSBuildToolsPath
        if ($subkey) {
            $msbuildPath = Join-Path $subkey "msbuild.exe"
        }
    }

    if (Test-Path $vs15key) {
        $key = Get-ItemProperty $vs15key
        $subkey = $key."15.0"
        if ($subkey) {
            $msbuildPath = Join-Path $subkey "MSBuild\15.0\bin\amd64\msbuild.exe"
        }
    }

    return $msbuildPath

}

POSTing JsonObject With HttpClient From Web API

If using Newtonsoft.Json:

using Newtonsoft.Json;
using System.Net.Http;
using System.Text;

public static class Extensions
{
    public static StringContent AsJson(this object o)
        => new StringContent(JsonConvert.SerializeObject(o), Encoding.UTF8, "application/json");
}

Example:

var httpClient = new HttpClient();
var url = "https://www.duolingo.com/2016-04-13/login?fields=";
var data = new { identifier = "username", password = "password" };
var result = await httpClient.PostAsync(url, data.AsJson())

Combine two tables that have no common fields

Joining Non-Related Tables

enter image description here

Demo SQL Script

IF OBJECT_ID('Tempdb..#T1') IS NOT NULL  DROP TABLE #T1;

CREATE TABLE #T1 (T1_Name VARCHAR(75));

INSERT INTO #T1 (T1_Name) VALUES ('Animal'),('Bat'),('Cat'),('Duet');

SELECT * FROM #T1;

IF OBJECT_ID('Tempdb..#T2') IS NOT NULL  DROP TABLE #T2;

CREATE TABLE #T2 (T2_Class VARCHAR(10));

INSERT INTO #T2 (T2_Class) VALUES ('Z'),('T'),('H'); 

SELECT * FROM #T2;

To Join Non-Related Tables , we are going to introduce one common joining column of Serial Numbers like below.

SQL Script

SELECT T1.T1_Name,ISNULL(T2.T2_Class,'') AS T2_Class FROM
( SELECT T1_Name,ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS S_NO FROM #T1) T1
LEFT JOIN
( SELECT T2_Class,ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS S_NO FROM #T2) T2
ON t1.S_NO=T2.S_NO;

How to use gitignore command in git

There are several ways to use gitignore git

  • specifying by the specific filename. for example, to ignore a file
    called readme.txt, just need to write readme.txt in .gitignore file.
  • you can also write the name of the file extension. For example, to
    ignore all .txt files, write *.txt.
  • you can also ignore a whole folder. for example you want to ignore
    folder named test. Then just write test/ in the file.

just create a .gitignore file and write in whatever you want to ignore a sample gitignore file would be:

# NPM packages folder.
node_modules

# Build files
dist/

# lock files
yarn.lock
package-lock.json

# Logs
logs
*.log
npm-debug.log*

# node-waf configuration
.lock-wscript

# Optional npm cache directory
.npm

# Optional REPL history
.node_repl_history

# Jest Coverage
coverage

.history/

You can find more on git documentation gitignore

Why does Oracle not find oci.dll?

I just installed Oracle Instant Client 18_3 with the SDK. The PATH and ENV variable is set as instructed on the install page but I get the OCl.dll not found error. I searched the entire drive recursively and no such DLL exists.

So now what?

With the install instructions (not updated for 18_3) and downloads there are MISTAKES at step 13, so watch out for that.

When you create the folder structure for the downloads just write them the old way "c:\oraclient". Then when you unzip the basic, SDK and instant Client install for Windows 10_x64 extract them to "C:\oraclient\", because they all write to the same default folder. Then, when you set the ENV variable (which is no longer ORACLE_HOME, but now is OCI_LIB64) and the PATH, you will point to "C:\oraclient\instantclient_18_3".

To be sure you got it all right drill down and look for any duplicate "instantclient_18_3" folders. If you do have those cut and paste the CONTENTS to the root folder "C:\oraclient\instantclient_18_3\" folder.

Whoever works on the documentation at Oracle needs to troubleshoot better. I've seen "C:\oreclient_dir_install", "c:\oracle", "c:\oreclient" and "c:\oraclient" all mentioned as install directories, all for Windows x64 installs

BTW, install the C++ redist it helps. The 18.3 Basic package requires the Microsoft Visual Studio 2013 Redistributable.

Which type of folder structure should be used with Angular 2?

I’ve been using ng cli lately, and it was really tough to find a good way to structure my code.

The most efficient one I've seen so far comes from mrholek repository (https://github.com/mrholek/CoreUI-Angular).

This folder structure allows you to keep your root project clean and structure your components, it avoids redundant (sometimes useless) naming convention of the official Style Guide.

Also it’s, this structure is useful to group import when it’s needed and avoid having 30 lines of import for a single file.

src
|
|___ app
|
|   |___ components/shared
|   |   |___ header
|   |
|   |___ containers/layout
|   |   |___ layout1
|   |
|   |___ directives
|   |   |___ sidebar
|   |
|   |___ services
|   |   |___ *user.service.ts* 
|   | 
|   |___ guards
|   |   |___ *auth.guard.ts* 
|   |
|   |___ views
|   |   |___ about  
|   |
|   |___ *app.component.ts*
|   |
|   |___ *app.module.ts*
|   |
|   |___ *app.routing.ts*
|
|___ assets
|
|___ environments
|
|___ img
|   
|___ scss
|
|___ *index.html*
|
|___ *main.ts*

Reusing a PreparedStatement multiple times

The loop in your code is only an over-simplified example, right?

It would be better to create the PreparedStatement only once, and re-use it over and over again in the loop.

In situations where that is not possible (because it complicated the program flow too much), it is still beneficial to use a PreparedStatement, even if you use it only once, because the server-side of the work (parsing the SQL and caching the execution plan), will still be reduced.

To address the situation that you want to re-use the Java-side PreparedStatement, some JDBC drivers (such as Oracle) have a caching feature: If you create a PreparedStatement for the same SQL on the same connection, it will give you the same (cached) instance.

About multi-threading: I do not think JDBC connections can be shared across multiple threads (i.e. used concurrently by multiple threads) anyway. Every thread should get his own connection from the pool, use it, and return it to the pool again.

What are all codecs and formats supported by FFmpeg?

Codecs proper:

ffmpeg -codecs

Formats:

ffmpeg -formats

Exporting to .xlsx using Microsoft.Office.Interop.Excel SaveAs Error

Try changing the second parameter in the SaveAs call to Excel.XlFileFormat.xlWorkbookDefault.

When I did that, I generated an xlsx file that I was able to successfully open. (Before making the change, I could produce an xlsx file, but I was unable to open it.)

Also, I'm not sure if it matters or not, but I'm using the Excel 12.0 object library.

Requests (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.") Error in PyCharm requesting website

going to the website: gives me following information from developer tool and looking at headers. (right click --> inspect. then open network tab and check headers)

  • Request URL: http://www.msft.com/
  • Request Method: GET
  • Status Code:200 OK
  • Remote Address: 205.178.189.130:80
  • Referrer Policy:no-referrer-when-downgrade

So we see we need to perform a request to HTTP, not HTTPS.

import requests


def Earlybird():
    url = 'http://msft.com/'
    response = requests.get(url)
    print(response.text)

if __name__ == '__main__':
    Earlybird()

Socket send and receive byte array

You need to either have the message be a fixed size, or you need to send the size or you need to use some separator characters.

This is the easiest case for a known size (100 bytes):

in = new DataInputStream(server.getInputStream());
byte[] message = new byte[100]; // the well known size
in.readFully(message);

In this case DataInputStream makes sense as it offers readFully(). If you don't use it, you need to loop yourself until the expected number of bytes is read.

Regex to match any character including new lines

Add the s modifier to your regex to cause . to match newlines:

$string =~ /(START)(.+?)(END)/s;

Pandas - Plotting a stacked Bar Chart

Are you getting errors, or just not sure where to start?

%pylab inline
import pandas as pd
import matplotlib.pyplot as plt

df2 = df.groupby(['Name', 'Abuse/NFF'])['Name'].count().unstack('Abuse/NFF').fillna(0)
df2[['abuse','nff']].plot(kind='bar', stacked=True)

stacked bar plot

How to convert all tables from MyISAM into InnoDB?

This is a simple php script.

<?php
    @error_reporting(E_ALL | E_STRICT);
    @ini_set('display_errors', '1');


    $con = mysql_connect('server', 'user', 'pass');
    $dbName = 'moodle2014';

    $sql = "SELECT table_name FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = '".$dbName."';";
    $rs = mysql_query($sql, $con);

    $count = 0;
    $ok = 0;
    while($row = mysql_fetch_array($rs)){
            $count ++;
            $tbl = $row[0];
            $sql = "ALTER TABLE ".$dbName.".".$tbl." ENGINE=INNODB;";
            $resultado = mysql_query($sql);
            if ($resultado){
                    $ok ++;
                    echo $sql."<hr/>";
            }
    }
    if ($count == $ok){
            echo '<div style="color: green"><b>ALL OK</b></div>';
    }else{
            echo '<div style="color: red"><b>ERRORS</b>Total tables: '.$count.', updated tables:'.$ok.'</div>';
    }

How can you run a command in bash over and over until success?

until passwd
do
  echo "Try again"
done

or

while ! passwd
do
  echo "Try again"
done

Difference between MEAN.js and MEAN.io

First of all, MEAN is an acronym for MongoDB, Express, Angular and Node.js.

It generically identifies the combined used of these technologies in a "stack". There is no such a thing as "The MEAN framework".

Lior Kesos at Linnovate took advantage of this confusion. He bought the domain MEAN.io and put some code at https://github.com/linnovate/mean

They luckily received a lot of publicity, and theree are more and more articles and video about MEAN. When you Google "mean framework", mean.io is the first in the list.

Unfortunately the code at https://github.com/linnovate/mean seems poorly engineered.

In February I fell in the trap myself. The site mean.io had a catchy design and the Github repo had 1000+ stars. The idea of questioning the quality did not even pass through my mind. I started experimenting with it but it did not take too long to stumble upon things that were not working, and puzzling pieces of code.

The commit history was also pretty concerning. They re-engineered the code and directory structure multiple times, and merging the new changes is too time consuming.

The nice things about both mean.io and mean.js code is that they come with Bootstrap integration. They also come with Facebook, Github, Linkedin etc authentication through PassportJs and an example of a model (Article) on the backend on MongoDB that sync with the frontend model with AngularJS.

According to Linnovate's website:

Linnovate is the leading Open Source company in Israel, with the most experienced team in the country, dedicated to the creation of high-end open source solutions. Linnovate is the only company in Israel which gives an A-Z services for enterprises for building and maintaining their next web project.

From the website it looks like that their core skill set is Drupal (a PHP content management system) and only lately they started using Node.js and AngularJS.

Lately I was reading the Mean.js Blog and things became clearer. My understanding is that the main Javascript developer (Amos Haviv) left Linnovate to work on Mean.js leaving MEAN.io project with people that are novice Node.js developers that are slowing understanding how things are supposed to work.

In the future things may change but for now I would avoid to use mean.io. If you are looking for a boilerplate for a quickstart Mean.js seems a better option than mean.io.

How do I center an anchor element in CSS?

Two options, that have different uses:

HTML:

<a class="example" href="http://www.example.com">example</a>

CSS:

.example { text-align: center; }

Or:

.example { display:block; width:100px; margin:0 auto;}

Python requests library how to pass Authorization header with single token

i founded here, its ok with me for linkedin: https://auth0.com/docs/flows/guides/auth-code/call-api-auth-code so my code with with linkedin login here:

ref = 'https://api.linkedin.com/v2/me'
headers = {"content-type": "application/json; charset=UTF-8",'Authorization':'Bearer {}'.format(access_token)}
Linkedin_user_info = requests.get(ref1, headers=headers).json()

Pull all images from a specified directory and then display them

Strict Standards: Only variables should be passed by reference in /home/aadarshi/public_html/----------/upload/view.php on line 32

and the code is:

<?php

echo scanDirectoryImages("uploads");

/**
* Recursively search through directory for images and display them
* 
* @param  array  $exts
* @param  string $directory
* @return string
*/
function scanDirectoryImages($directory, array $exts = array('jpeg', 'jpg', 'gif', 'png'))
{
if (substr($directory, -1) == '/') {
    $directory = substr($directory, 0, -1);
}
$html = '';
if (
    is_readable($directory)
    && (file_exists($directory) || is_dir($directory))
) {
    $directoryList = opendir($directory);
    while($file = readdir($directoryList)) {
        if ($file != '.' && $file != '..') {
            $path = $directory . '/' . $file;
            if (is_readable($path)) {
                if (is_dir($path)) {
                    return scanDirectoryImages($path, $exts);
                }
                if (
                    is_file($path)
                    && in_array(end(explode('.', end(explode('/', $path)))),   $exts)
                ) {
                    $html .= '<a href="' . $path . '"><img src="' . $path
                        . '" style="max-height:100px;max-width:100px" />  </a>';
                }
            }
        }
    }
    closedir($directoryList);
}
return $html;
}

Custom "confirm" dialog in JavaScript?

Faced with the same problem, I was able to solve it using only vanilla JS, but in an ugly way. To be more accurate, in a non-procedural way. I removed all my function parameters and return values and replaced them with global variables, and now the functions only serve as containers for lines of code - they're no longer logical units.

In my case, I also had the added complication of needing many confirmations (as a parser works through a text). My solution was to put everything up to the first confirmation in a JS function that ends by painting my custom popup on the screen, and then terminating.

Then the buttons in my popup call another function that uses the answer and then continues working (parsing) as usual up to the next confirmation, when it again paints the screen and then terminates. This second function is called as often as needed.

Both functions also recognize when the work is done - they do a little cleanup and then finish for good. The result is that I have complete control of the popups; the price I paid is in elegance.

How to use conditional statement within child attribute of a Flutter Widget (Center Widget)

Here is the solution. I have fixed it. Here is the code

child: _status(data[index]["status"]),

Widget _status(status) {
  if (status == "3") {
    return Text('Process');
  } else if(status == "1") {
    return Text('Order');
  } else {
    return Text("Waiting");
  }
}

Mixed mode assembly is built against version ‘v2.0.50727' of the runtime

If the error happens with error column "File" as SGEN, then the fix needs to be in a file sgen.exe.config, next to sgen.exe. For example, for VS 2015, create C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.6 Tools\sgen.exe.config. Minimum file contents: <configuration><startup useLegacyV2RuntimeActivationPolicy="true"/></configuration>

Source: SGEN Mixed mode assembly

Simplest two-way encryption using PHP

PHP 7.2 moved completely away from Mcrypt and the encryption now is based on the maintainable Libsodium library.

All your encryption needs can be basically resolved through Libsodium library.

// On Alice's computer:
$msg = 'This comes from Alice.';
$signed_msg = sodium_crypto_sign($msg, $secret_sign_key);


// On Bob's computer:
$original_msg = sodium_crypto_sign_open($signed_msg, $alice_sign_publickey);
if ($original_msg === false) {
    throw new Exception('Invalid signature');
} else {
    echo $original_msg; // Displays "This comes from Alice."
}

Libsodium documentation: https://github.com/paragonie/pecl-libsodium-doc

extract digits in a simple way from a python string

The simplest way to extract a number from a string is to use regular expressions and findall.

>>> import re
>>> s = '300 gm'
>>> re.findall('\d+', s)
['300']
>>> s = '300 gm 200 kgm some more stuff a number: 439843'
>>> re.findall('\d+', s)
['300', '200', '439843']

It might be that you need something more complex, but this is a good first step.

Note that you'll still have to call int on the result to get a proper numeric type (rather than another string):

>>> map(int, re.findall('\d+', s))
[300, 200, 439843]

Restart container within pod

There was an issue in coredns pod, I deleted such pod by

kubectl delete pod -n=kube-system coredns-fb8b8dccf-8ggcf

Its pod will restart automatically.

How to display an image from a path in asp.net MVC 4 and Razor view?

In your View try like this

  <img src= "@Url.Content(Model.ImagePath)" alt="Image" />

how can the textbox width be reduced?

rows and cols are required attributes, so you should have them whether you really need them or not. They set the number of rows and number of columns respectively.

http://htmldog.com/reference/htmltags/textarea/

How do I remove objects from an array in Java?

You can use external library:

org.apache.commons.lang.ArrayUtils.remove(java.lang.Object[] array, int index)

It is in project Apache Commons Lang http://commons.apache.org/lang/

Scanner is never closed

I am assuming you are using java 7, thus you get a compiler warning, when you don't close the resource you should close your scanner usually in a finally block.

Scanner scanner = null;
try {
    scanner = new Scanner(System.in);
    //rest of the code
}
finally {
    if(scanner!=null)
        scanner.close();
}

Or even better: use the new Try with resource statement:

try(Scanner scanner = new Scanner(System.in)){
    //rest of your code
}

Is it a bad practice to use an if-statement without curly braces?

The problem with the first version is that if you go back and add a second statement to the if or else clauses without remembering to add the curly braces, your code will break in unexpected and amusing ways.

Maintainability-wise, it's always smarter to use the second form.

EDIT: Ned points this out in the comments, but it's worth linking to here, too, I think. This is not just some ivory-tower hypothetical bullshit: https://www.imperialviolet.org/2014/02/22/applebug.html

read string from .resx file in C#

This example is from the MSDN page on ResourceManager.GetString():

// Create a resource manager to retrieve resources.
ResourceManager rm = new ResourceManager("items", Assembly.GetExecutingAssembly());

// Retrieve the value of the string resource named "welcome".
// The resource manager will retrieve the value of the  
// localized resource using the caller's current culture setting.
String str = rm.GetString("welcome");

jQuery: go to URL with target="_blank"

Try using the following code.

$(document).ready(function(){
    $("a[@href^='http']").attr('target','_blank');
});

jquery - How to determine if a div changes its height or any css attribute?

Please don't use techniques described in other answers here. They are either not working with css3 animations size changes, floating layout changes or changes that don't come from jQuery land. You can use a resize-detector, a event-based approach, that doesn't waste your CPU time.

https://github.com/marcj/css-element-queries

It contains a ResizeSensor class you can use for that purpose.

new ResizeSensor(jQuery('#mainContent'), function(){ 
    console.log('main content dimension changed');
});

Disclaimer: I wrote this library

How to send FormData objects with Ajax-requests in jQuery?

You can use the $.ajax beforeSend event to manipulate the header.

beforeSend: function(xhr) { 
    xhr.setRequestHeader('Content-Type', 'multipart/form-data');
}

See this link for additional information: http://msdn.microsoft.com/en-us/library/ms536752(v=vs.85).aspx

How to import popper.js?

I deleted any existing popper directories, then ran

npm install --save popper.js angular-popper

How to use npm with ASP.NET Core

What is the right approach for doing this?

There are a lot of "right" approaches, you just have decide which one best suites your needs. It appears as though you're misunderstanding how to use node_modules...

If you're familiar with NuGet you should think of npm as its client-side counterpart. Where the node_modules directory is like the bin directory for NuGet. The idea is that this directory is just a common location for storing packages, in my opinion it is better to take a dependency on the packages you need as you have done in the package.json. Then use a task runner like Gulp for example to copy the files you need into your desired wwwroot location.

I wrote a blog post about this back in January that details npm, Gulp and a whole bunch of other details that are still relevant today. Additionally, someone called attention to my SO question I asked and ultimately answered myself here, which is probably helpful.

I created a Gist that shows the gulpfile.js as an example.

In your Startup.cs it is still important to use static files:

app.UseStaticFiles();

This will ensure that your application can access what it needs.

Unable to resolve host "<URL here>" No address associated with host name

You probably don't have the INTERNET permission. Try adding this to your AndroidManifest.xml file, right before </manifest>:

<uses-permission android:name="android.permission.INTERNET" />

Note: the above doesn't have to be right before the </manifest> tag, but that is a good / correct place to put it.

Note: if this answer doesn't help in your case, read the other answers!

html 5 audio tag width

For those looking for an inline example, here is one:

<audio controls style="width: 200px;">
   <source src="http://somewhere.mp3" type="audio/mpeg">
</audio>

It doesn't seem to respect a "height" setting, at least not awesomely. But you can always "customize" the controls but creating your own controls (instead of using the built-in ones) or using somebody's widget that similarly creates its own :)

How do I iterate and modify Java Sets?

You can do what you want if you use an iterator object to go over the elements in your set. You can remove them on the go an it's ok. However removing them while in a for loop (either "standard", of the for each kind) will get you in trouble:

Set<Integer> set = new TreeSet<Integer>();
    set.add(1);
    set.add(2);
    set.add(3);

    //good way:
    Iterator<Integer> iterator = set.iterator();
    while(iterator.hasNext()) {
        Integer setElement = iterator.next();
        if(setElement==2) {
            iterator.remove();
        }
    }

    //bad way:
    for(Integer setElement:set) {
        if(setElement==2) {
            //might work or might throw exception, Java calls it indefined behaviour:
            set.remove(setElement);
        } 
    }

As per @mrgloom's comment, here are more details as to why the "bad" way described above is, well... bad :

Without getting into too much details about how Java implements this, at a high level, we can say that the "bad" way is bad because it is clearly stipulated as such in the Java docs:

https://docs.oracle.com/javase/8/docs/api/java/util/ConcurrentModificationException.html

stipulate, amongst others, that (emphasis mine):

"For example, it is not generally permissible for one thread to modify a Collection while another thread is iterating over it. In general, the results of the iteration are undefined under these circumstances. Some Iterator implementations (including those of all the general purpose collection implementations provided by the JRE) may choose to throw this exception if this behavior is detected" (...)

"Note that this exception does not always indicate that an object has been concurrently modified by a different thread. If a single thread issues a sequence of method invocations that violates the contract of an object, the object may throw this exception. For example, if a thread modifies a collection directly while it is iterating over the collection with a fail-fast iterator, the iterator will throw this exception."

To go more into details: an object that can be used in a forEach loop needs to implement the "java.lang.Iterable" interface (javadoc here). This produces an Iterator (via the "Iterator" method found in this interface), which is instantiated on demand, and will contain internally a reference to the Iterable object from which it was created. However, when an Iterable object is used in a forEach loop, the instance of this iterator is hidden to the user (you cannot access it yourself in any way).

This, coupled with the fact that an Iterator is pretty stateful, i.e. in order to do its magic and have coherent responses for its "next" and "hasNext" methods it needs that the backing object is not changed by something else than the iterator itself while it's iterating, makes it so that it will throw an exception as soon as it detects that something changed in the backing object while it is iterating over it.

Java calls this "fail-fast" iteration: i.e. there are some actions, usually those that modify an Iterable instance (while an Iterator is iterating over it). The "fail" part of the "fail-fast" notion refers to the ability of an Iterator to detect when such "fail" actions happen. The "fast" part of the "fail-fast" (and, which in my opinion should be called "best-effort-fast"), will terminate the iteration via ConcurrentModificationException as soon as it can detect that a "fail" action has happen.

Run a Docker image as a container

Get the name or id of the image you would like to run, with this command:

docker images

The Docker run command is used in the following way:

docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

Below I have included the dispatch, name, publish, volume and restart options before specifying the image name or id:

docker run -d --name  container-name -p localhost:80:80 -v $HOME/myContainer/configDir:/myImage/configDir --restart=always image-name

Where:

--detach , -d        Run container in background and print container ID
--name                Assign a name to the container
--publish , -p        Publish a container’s port(s) to the host
--volume , -v        Bind mount a volume
--restart            Restart policy to apply when a container exits

For more information, please check out the official Docker run reference.

C# string replace

You need to escape the double-quotes inside the search string, like this:

string orig = "\"Text\",\"Text\",\"Text\"";
string res = orig.Replace("\",\"", ";");

Note that the replacement does not occur "in place", because .NET strings are immutable. The original string will remain the same after the call; only the returned string res will have the replacements.

Oracle SELECT TOP 10 records

If you are using Oracle 12c, use:

FETCH NEXT N ROWS ONLY

SELECT DISTINCT 
  APP_ID, 
  NAME, 
  STORAGE_GB, 
  HISTORY_CREATED, 
  TO_CHAR(HISTORY_DATE, 'DD.MM.YYYY') AS HISTORY_DATE  
  FROM HISTORY WHERE 
    STORAGE_GB IS NOT NULL AND 
      APP_ID NOT IN (SELECT APP_ID FROM HISTORY WHERE TO_CHAR(HISTORY_DATE, 'DD.MM.YYYY') ='06.02.2009')
  ORDER BY STORAGE_GB DESC
FETCH NEXT 10 ROWS ONLY

More info: http://docs.oracle.com/javadb/10.5.3.0/ref/rrefsqljoffsetfetch.html

Numpy Resize/Rescale Image

One-line numpy solution for downsampling (by 2):

smaller_img = bigger_img[::2, ::2]

And upsampling (by 2):

bigger_img = smaller_img.repeat(2, axis=0).repeat(2, axis=1)

(this asssumes HxWxC shaped image. h/t to L. Kärkkäinen in the comments above. note this method only allows whole integer resizing (e.g., 2x but not 1.5x))

"Unable to locate tools.jar" when running ant

The order of items in the PATH matters. If there are multiple entries for various java installations, the first one in your PATH will be used.

I have had similar issues after installing a product, like Oracle, that puts it's JRE at the beginning of the PATH.

Ensure that the JDK you want to be loaded is the first entry in your PATH (or at least that it appears before C:\Program Files\Java\jre6\bin appears).

How to use conditional breakpoint in Eclipse?

A way that might be more convenient: where you want a breakpoint, write a no-op if statement and set a breakpoint in its contents.

if(tablist[i].equalsIgnoreCase("LEADDELEGATES")) {
-->    int noop = 0; //don't do anything
}

(the breakpoint is represented by the arrow)

This way, the breakpoint only triggers if your condition is true. This could potentially be easier without that many pop-ups.

How can I open Windows Explorer to a certain directory from within a WPF app?

You can use System.Diagnostics.Process.Start.

Or use the WinApi directly with something like the following, which will launch explorer.exe. You can use the fourth parameter to ShellExecute to give it a starting directory.

public partial class Window1 : Window
{
    public Window1()
    {
        ShellExecute(IntPtr.Zero, "open", "explorer.exe", "", "", ShowCommands.SW_NORMAL);
        InitializeComponent();
    }

    public enum ShowCommands : int
    {
        SW_HIDE = 0,
        SW_SHOWNORMAL = 1,
        SW_NORMAL = 1,
        SW_SHOWMINIMIZED = 2,
        SW_SHOWMAXIMIZED = 3,
        SW_MAXIMIZE = 3,
        SW_SHOWNOACTIVATE = 4,
        SW_SHOW = 5,
        SW_MINIMIZE = 6,
        SW_SHOWMINNOACTIVE = 7,
        SW_SHOWNA = 8,
        SW_RESTORE = 9,
        SW_SHOWDEFAULT = 10,
        SW_FORCEMINIMIZE = 11,
        SW_MAX = 11
    }

    [DllImport("shell32.dll")]
    static extern IntPtr ShellExecute(
        IntPtr hwnd,
        string lpOperation,
        string lpFile,
        string lpParameters,
        string lpDirectory,
        ShowCommands nShowCmd);
}

The declarations come from the pinvoke.net website.

C# Sort and OrderBy comparison

Darin Dimitrov's answer shows that OrderBy is slightly faster than List.Sort when faced with already-sorted input. I modified his code so it repeatedly sorts the unsorted data, and OrderBy is in most cases slightly slower.

Furthermore, the OrderBy test uses ToArray to force enumeration of the Linq enumerator, but that obviously returns a type (Person[]) which is different from the input type (List<Person>). I therefore re-ran the test using ToList rather than ToArray and got an even bigger difference:

Sort: 25175ms
OrderBy: 30259ms
OrderByWithToList: 31458ms

The code:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;

class Program
{
    class NameComparer : IComparer<string>
    {
        public int Compare(string x, string y)
        {
            return string.Compare(x, y, true);
        }
    }

    class Person
    {
        public Person(string id, string name)
        {
            Id = id;
            Name = name;
        }
        public string Id { get; set; }
        public string Name { get; set; }
        public override string ToString()
        {
            return Id + ": " + Name;
        }
    }

    private static Random randomSeed = new Random();
    public static string RandomString(int size, bool lowerCase)
    {
        var sb = new StringBuilder(size);
        int start = (lowerCase) ? 97 : 65;
        for (int i = 0; i < size; i++)
        {
            sb.Append((char)(26 * randomSeed.NextDouble() + start));
        }
        return sb.ToString();
    }

    private class PersonList : List<Person>
    {
        public PersonList(IEnumerable<Person> persons)
           : base(persons)
        {
        }

        public PersonList()
        {
        }

        public override string ToString()
        {
            var names = Math.Min(Count, 5);
            var builder = new StringBuilder();
            for (var i = 0; i < names; i++)
                builder.Append(this[i]).Append(", ");
            return builder.ToString();
        }
    }

    static void Main()
    {
        var persons = new PersonList();
        for (int i = 0; i < 100000; i++)
        {
            persons.Add(new Person("P" + i.ToString(), RandomString(5, true)));
        } 

        var unsortedPersons = new PersonList(persons);

        const int COUNT = 30;
        Stopwatch watch = new Stopwatch();
        for (int i = 0; i < COUNT; i++)
        {
            watch.Start();
            Sort(persons);
            watch.Stop();
            persons.Clear();
            persons.AddRange(unsortedPersons);
        }
        Console.WriteLine("Sort: {0}ms", watch.ElapsedMilliseconds);

        watch = new Stopwatch();
        for (int i = 0; i < COUNT; i++)
        {
            watch.Start();
            OrderBy(persons);
            watch.Stop();
            persons.Clear();
            persons.AddRange(unsortedPersons);
        }
        Console.WriteLine("OrderBy: {0}ms", watch.ElapsedMilliseconds);

        watch = new Stopwatch();
        for (int i = 0; i < COUNT; i++)
        {
            watch.Start();
            OrderByWithToList(persons);
            watch.Stop();
            persons.Clear();
            persons.AddRange(unsortedPersons);
        }
        Console.WriteLine("OrderByWithToList: {0}ms", watch.ElapsedMilliseconds);
    }

    static void Sort(List<Person> list)
    {
        list.Sort((p1, p2) => string.Compare(p1.Name, p2.Name, true));
    }

    static void OrderBy(List<Person> list)
    {
        var result = list.OrderBy(n => n.Name, new NameComparer()).ToArray();
    }

    static void OrderByWithToList(List<Person> list)
    {
        var result = list.OrderBy(n => n.Name, new NameComparer()).ToList();
    }
}

How do I get column datatype in Oracle with PL-SQL with low privileges?

You can use the desc command.

desc MY_TABLE

This will give you the column names, whether null is valid, and the datatype (and length if applicable)

How to convert String to DOM Document object in java?

     public static void main(String[] args) {
    final String xmlStr = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n"+
                            "<Emp id=\"1\"><name>Pankaj</name><age>25</age>\n"+
                            "<role>Developer</role><gen>Male</gen></Emp>";
   DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();  
        DocumentBuilder builder;  
        try 
        {  
            builder = factory.newDocumentBuilder();  
            Document doc = builder.parse( new InputSource( new StringReader( xmlStr )) ); 

        } catch (Exception e) {  
            e.printStackTrace();  
        } 
  }

Why does an SSH remote command get fewer environment variables then when run manually?

How about sourcing the profile before running the command?

ssh user@host "source /etc/profile; /path/script.sh"

You might find it best to change that to ~/.bash_profile, ~/.bashrc, or whatever.

(As here (linuxquestions.org))

Convert xlsx to csv in Linux with command line

You can do this with LibreOffice:

libreoffice --headless --convert-to csv $filename --outdir $outdir

For reasons not clear to me, you might need to run this with sudo. You can make LibreOffice work with sudo without requiring a password by adding this line to you sudoers file:

users ALL=(ALL) NOPASSWD: libreoffice

python date of the previous month

datetime and the datetime.timedelta classes are your friend.

  1. find today.
  2. use that to find the first day of this month.
  3. use timedelta to backup a single day, to the last day of the previous month.
  4. print the YYYYMM string you're looking for.

Like this:

 import datetime
 today = datetime.date.today()
 first = today.replace(day=1)
 lastMonth = first - datetime.timedelta(days=1)
 print(lastMonth.strftime("%Y%m"))

201202 is printed.

Set up a scheduled job?

I am not sure will this be useful for anyone, since I had to provide other users of the system to schedule the jobs, without giving them access to the actual server(windows) Task Scheduler, I created this reusable app.

Please note users have access to one shared folder on server where they can create required command/task/.bat file. This task then can be scheduled using this app.

App name is Django_Windows_Scheduler

ScreenShot: enter image description here

What's the difference between xsd:include and xsd:import?

The fundamental difference between include and import is that you must use import to refer to declarations or definitions that are in a different target namespace and you must use include to refer to declarations or definitions that are (or will be) in the same target namespace.

Source: https://web.archive.org/web/20070804031046/http://xsd.stylusstudio.com/2002Jun/post08016.htm

How do you properly use namespaces in C++?

Another difference between java and C++, is that in C++, the namespace hierarchy does not need to mach the filesystem layout. So I tend to put an entire reusable library in a single namespace, and subsystems within the library in subdirectories:

#include "lib/module1.h"
#include "lib/module2.h"

lib::class1 *v = new lib::class1();

I would only put the subsystems in nested namespaces if there was a possibility of a name conflict.

github changes not staged for commit

WARNING! THIS WILL DELETE THE ENTIRE GIT HISTORY FOR YOUR SUBMODULE. ONLY DO THIS IF YOU CREATED THE SUBMODULE BY ACCIDENT. CERTAINLY NOT WHAT YOU WANT TO DO IN MOST CASES.

In my situation, there was a sub-directory which had a .git directory.

What I do is simply remove that .git directory from my sub-directory.

JavaScript data grid for millions of rows

I suggest sigma grid, sigma grid has embed paging features which could support millions of rows. And also, you may need a remote paging to do it. see the demo http://www.sigmawidgets.com/products/sigma_grid2/demos/example_master_details.html

How to set a JavaScript breakpoint from code in Chrome?

As other have already said, debugger; is the way to go. I wrote a small script that you can use from the command line in a browser to set and remove breakpoint right before function call: http://andrijac.github.io/blog/2014/01/31/javascript-breakpoint/

How to enter a series of numbers automatically in Excel

Simple Answer:

In A1

=if(b1="","",row()) 

In A2

=if(b2="","",row())  

copy this down the column. Each time an entry is entered in column B the next number in order will be entered in column A.

Suppose you want the answer of 2 in a4 cell because of your heading & other stuff, you can write as

=if(b4="","",row()-2)

Scala vs. Groovy vs. Clojure

They can be differentiated with where they are coming from or which developers they're targeting mainly.

Groovy is a bit like scripting version of Java. Long time Java programmers feel at home when building agile applications backed by big architectures. Groovy on Grails is, as the name suggests similar to the Rails framework. For people who don't want to bother with Java's verbosity all the time.

Scala is an object oriented and functional programming language and Ruby or Python programmers may feel more closer to this one. It employs quite a lot of common good ideas found in these programming languages.

Clojure is a dialect of the Lisp programming language so Lisp, Scheme or Haskell developers may feel at home while developing with this language.

How to add \newpage in Rmarkdown in a smart way?

Simply \newpage or \pagebreak will work, e.g.

hello world
\newpage
```{r, echo=FALSE}
1+1
```
\pagebreak
```{r, echo=FALSE}
plot(1:10)
```

This solution assumes you are knitting PDF. For HTML, you can achieve a similar effect by adding a tag <P style="page-break-before: always">. Note that you likely won't see a page break in your browser (HTMLs don't have pages per se), but the printing layout will have it.

ERROR Source option 1.5 is no longer supported. Use 1.6 or later

In IntelliJ:

  1. Open Project Structure (?;) > Modules > YOUR MODULE -> Language level: set 9, in your case.
  2. Repeat for each module.

screenshot

creating a table in ionic

the issue of too long content @beenotung can be resolved by this css class :

.col{
  max-width :20% !important;
}

example fork from @jpoveda

How to get only the last part of a path in Python?

Use os.path.normpath, then os.path.basename:

>>> os.path.basename(os.path.normpath('/folderA/folderB/folderC/folderD/'))
'folderD'

The first strips off any trailing slashes, the second gives you the last part of the path. Using only basename gives everything after the last slash, which in this case is ''.

Python, TypeError: unhashable type: 'list'

The problem is that you can't use a list as the key in a dict, since dict keys need to be immutable. Use a tuple instead.

This is a list:

[x, y]

This is a tuple:

(x, y)

Note that in most cases, the ( and ) are optional, since , is what actually defines a tuple (as long as it's not surrounded by [] or {}, or used as a function argument).

You might find the section on tuples in the Python tutorial useful:

Though tuples may seem similar to lists, they are often used in different situations and for different purposes. Tuples are immutable, and usually contain an heterogeneous sequence of elements that are accessed via unpacking (see later in this section) or indexing (or even by attribute in the case of namedtuples). Lists are mutable, and their elements are usually homogeneous and are accessed by iterating over the list.

And in the section on dictionaries:

Unlike sequences, which are indexed by a range of numbers, dictionaries are indexed by keys, which can be any immutable type; strings and numbers can always be keys. Tuples can be used as keys if they contain only strings, numbers, or tuples; if a tuple contains any mutable object either directly or indirectly, it cannot be used as a key. You can’t use lists as keys, since lists can be modified in place using index assignments, slice assignments, or methods like append() and extend().


In case you're wondering what the error message means, it's complaining because there's no built-in hash function for lists (by design), and dictionaries are implemented as hash tables.

Javascript onclick hide div

just add onclick handler for anchor tag

onclick="this.parentNode.style.display = 'none'"

or change onclick handler for img tag

onclick="this.parentNode.parentNode.style.display = 'none'"

Importing from a relative path in Python

EDIT Nov 2014 (3 years later):

Python 2.6 and 3.x supports proper relative imports, where you can avoid doing anything hacky. With this method, you know you are getting a relative import rather than an absolute import. The '..' means, go to the directory above me:

from ..Common import Common

As a caveat, this will only work if you run your python as a module, from outside of the package. For example:

python -m Proj

Original hacky way

This method is still commonly used in some situations, where you aren't actually ever 'installing' your package. For example, it's popular with Django users.

You can add Common/ to your sys.path (the list of paths python looks at to import things):

import sys, os
sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'Common'))
import Common

os.path.dirname(__file__) just gives you the directory that your current python file is in, and then we navigate to 'Common/' the directory and import 'Common' the module.

Cloudfront custom-origin distribution returns 502 "ERROR The request could not be satisfied." for some URLs

I ran into this problem, which resolved itself after I stopped using a proxy. Maybe CloudFront is blacklisting some IPs.

What is git tag, How to create tags & How to checkout git remote tag(s)

In order to checkout a git tag , you would execute the following command

git checkout tags/tag-name -b branch-name

eg as mentioned below.

 git checkout tags/v1.0 -b v1.0-branch

To fetch the all tags use the command

git fetch --all --tags

Store images in a MongoDB database

var upload = multer({dest: "./uploads"});
var mongo = require('mongodb');
var Grid = require("gridfs-stream");
Grid.mongo = mongo;

router.post('/:id', upload.array('photos', 200), function(req, res, next){
gfs = Grid(db);
var ss = req.files;
   for(var j=0; j<ss.length; j++){
     var originalName = ss[j].originalname;
     var filename = ss[j].filename;
     var writestream = gfs.createWriteStream({
         filename: originalName
     });
    fs.createReadStream("./uploads/" + filename).pipe(writestream);
   }
});

In your view:

<form action="/" method="post" enctype="multipart/form-data">
<input type="file" name="photos">

With this code you can add single as well as multiple images in MongoDB.

Use Device Login on Smart TV / Console

They change it again. At this moment documentation does not fit actual situation.

Commonly all works as expected with one small difference. Login from Devices config now moves to Products -> Facebook Login.

So you need to:

  • get your App id from headline,
  • get Client Token from app Settings -> Advanced. There is also Native or desktop app? question/config. I turn it on.
  • Add product (just click on Add product and then Get started on Facebook login. Move back to your app config, click to newly added Facebook login and you'll see your Login from Devices config.

HTML 5 Favicon - Support?

The answers provided (at the time of this post) are link only answers so I thought I would summarize the links into an answer and what I will be using.

When working to create Cross Browser Favicons (including touch icons) there are several things to consider.

The first (of course) is Internet Explorer. IE does not support PNG favicons until version 11. So our first line is a conditional comment for favicons in IE 9 and below:

<!--[if IE]><link rel="shortcut icon" href="path/to/favicon.ico"><![endif]-->

To cover the uses of the icon create it at 32x32 pixels. Notice the rel="shortcut icon" for IE to recognize the icon it needs the word shortcut which is not standard. Also we wrap the .ico favicon in a IE conditional comment because Chrome and Safari will use the .ico file if it is present, despite other options available, not what we would like.

The above covers IE up to IE 9. IE 11 accepts PNG favicons, however, IE 10 does not. Also IE 10 does not read conditional comments thus IE 10 won't show a favicon. With IE 11 and Edge available I don't see IE 10 in widespread use, so I ignore this browser.

For the rest of the browsers we are going to use the standard way to cite a favicon:

<link rel="icon" href="path/to/favicon.png">

This icon should be 196x196 pixels in size to cover all devices that may use this icon.

To cover touch icons on mobile devices we are going to use Apple's proprietary way to cite a touch icon:

<link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png">

Using rel="apple-touch-icon-precomposed" will not apply the reflective shine when bookmarked on iOS. To have iOS apply the shine use rel="apple-touch-icon". This icon should be sized to 180x180 pixels as that is the current size recommend by Apple for the latest iPhones and iPads. I have read Blackberry will also use rel="apple-touch-icon-precomposed".

As a note: Chrome for Android states:

The apple-touch-* are deprecated, and will be supported only for a short time. (Written as of beta for m31 of Chrome).

Custom Tiles for IE 11+ on Windows 8.1+

IE 11+ on Windows 8.1+ does offer a way to create pinned tiles for your site.

Microsoft recommends creating a few tiles at the following size:

Small: 128 x 128

Medium: 270 x 270

Wide: 558 x 270

Large: 558 x 558

These should be transparent images as we will define a color background next.

Once these images are created you should create an xml file called browserconfig.xml with the following code:

<?xml version="1.0" encoding="utf-8"?>
<browserconfig>
  <msapplication>
    <tile>
      <square70x70logo src="images/smalltile.png"/>
      <square150x150logo src="images/mediumtile.png"/>
      <wide310x150logo src="images/widetile.png"/>
      <square310x310logo src="images/largetile.png"/>
      <TileColor>#009900</TileColor>
    </tile>
  </msapplication>
</browserconfig>

Save this xml file in the root of your site. When a site is pinned IE will look for this file. If you want to name the xml file something different or have it in a different location add this meta tag to the head:

<meta name="msapplication-config" content="path-to-browserconfig/custom-name.xml" />

For additional information on IE 11+ custom tiles and using the XML file visit Microsoft's website.

Putting it all together:

To put it all together the above code would look like this:

<!-- For IE 9 and below. ICO should be 32x32 pixels in size -->
<!--[if IE]><link rel="shortcut icon" href="path/to/favicon.ico"><![endif]-->

<!-- Touch Icons - iOS and Android 2.1+ 180x180 pixels in size. --> 
<link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png">

<!-- Firefox, Chrome, Safari, IE 11+ and Opera. 196x196 pixels in size. -->
<link rel="icon" href="path/to/favicon.png">

Windows Phone Live Tiles

If a user is using a Windows Phone they can pin a website to the start screen of their phone. Unfortunately, when they do this it displays a screenshot of your phone, not a favicon (not even the MS specific code referenced above). To make a "Live Tile" for Windows Phone Users for your website one must use the following code:

Here are detailed instructions from Microsoft but here is a synopsis:

Step 1

Create a square image for your website, to support hi-res screens create it at 768x768 pixels in size.

Step 2

Add a hidden overlay of this image. Here is example code from Microsoft:

<div id="TileOverlay" onclick="ToggleTileOverlay()" style='background-color: Highlight; height: 100%; width: 100%; top: 0px; left: 0px; position: fixed; color: black; visibility: hidden'>
  <img src="customtile.png" width="320" height="320" />
  <div style='margin-top: 40px'>
     Add text/graphic asking user to pin to start using the menu...
  </div>
</div>

Step 3

You then can add thew following line to add a pin to start link:

<a href="javascript:ToggleTileOverlay()">Pin this site to your start screen</a>

Microsoft recommends that you detect windows phone and only show that link to those users since it won't work for other users.

Step 4

Next you add some JS to toggle the overlay visibility

<script>
function ToggleTileOverlay() {
 var newVisibility =     (document.getElementById('TileOverlay').style.visibility == 'visible') ? 'hidden' : 'visible';
 document.getElementById('TileOverlay').style.visibility =    newVisibility;
}
</script>

Note on Sizes

I am using one size as every browser will scale down the image as necessary. I could add more HTML to specify multiple sizes if desired for those with a lower bandwidth but I am already compressing the PNG files heavily using TinyPNG and I find this unnecessary for my purposes. Also, according to philippe_b's answer Chrome and Firefox have bugs that cause the browser to load all sizes of icons. Using one large icon may be better than multiple smaller ones because of this.

Further Reading

For those who would like more details see the links below:

How to create string with multiple spaces in JavaScript

With template literals, you can use multiple spaces or multi-line strings and string interpolation. Template Literals are a new ES2015 / ES6 feature that allows you to work with strings. The syntax is very simple, just use backticks instead of single or double quotes:

let a = `something                 something`;

and to make multiline strings just press enter to create a new line, with no special characters:

let a = `something 

    
                         something`;

The results are exactly the same as you write in the string.

How can I create a dropdown menu from a List in Tkinter?

To create a "drop down menu" you can use OptionMenu in tkinter

Example of a basic OptionMenu:

from Tkinter import *

master = Tk()

variable = StringVar(master)
variable.set("one") # default value

w = OptionMenu(master, variable, "one", "two", "three")
w.pack()

mainloop()

More information (including the script above) can be found here.


Creating an OptionMenu of the months from a list would be as simple as:

from tkinter import *

OPTIONS = [
"Jan",
"Feb",
"Mar"
] #etc

master = Tk()

variable = StringVar(master)
variable.set(OPTIONS[0]) # default value

w = OptionMenu(master, variable, *OPTIONS)
w.pack()

mainloop()

In order to retrieve the value the user has selected you can simply use a .get() on the variable that we assigned to the widget, in the below case this is variable:

from tkinter import *

OPTIONS = [
"Jan",
"Feb",
"Mar"
] #etc

master = Tk()

variable = StringVar(master)
variable.set(OPTIONS[0]) # default value

w = OptionMenu(master, variable, *OPTIONS)
w.pack()

def ok():
    print ("value is:" + variable.get())

button = Button(master, text="OK", command=ok)
button.pack()

mainloop()

I would highly recommend reading through this site for further basic tkinter information as the above examples are modified from that site.

PHP: date function to get month of the current date

To compare with an int do this:

<?php
$date = date("m");
$dateToCompareTo = 05;
if (strval($date) == strval($dateToCompareTo)) {
    echo "They are the same";
}
?>

Swift: Testing optionals for nil

Now you can do in swift the following thing which allows you to regain a little bit of the objective-c if nil else

if textfieldDate.text?.isEmpty ?? true {

}

error LNK2001: unresolved external symbol (C++)

Sounds like you are using Microsoft Visual C++. If that is the case, then the most possibility is that you don't compile your two.cpp with one.cpp (one.cpp is the implementation for one.h).

If you are from command line (cmd.exe), then try this first: cl -o two.exe one.cpp two.cpp

If you are from IDE, right click on the project name from Solution Explore. Then choose Add, Existing Item.... Add one.cpp into your project.

ASP.NET MVC3 Razor - Html.ActionLink style

Reviving an old question because it seems to appear at the top of search results.

I wanted to retain transition effects while still being able to style the actionlink so I came up with this solution.

  1. I wrapped the action link with a div that would contain the parent style:
<div class="parent-style-one">
      @Html.ActionLink("Homepage", "Home", "Home")
</div>
  1. Next I create the CSS for the div, this will be the parent css and will be inherited by the child elements such as the action link.
  .parent-style-one {
     /* your styles here */
  }
  1. Because all an action link is, is an element when broken down as html so you just need to target that element in your css selection:
  .parent-style-one a {
     text-decoration: none;
  }
  1. For transition effects I did this:
  .parent-style-one a:hover {
        text-decoration: underline;
        -webkit-transition-duration: 1.1s; /* Safari */
        transition-duration: 1.1s;         
  }

This way I only target the child elements of the div in this case the action link and still be able to apply transition effects.

Bootstrap close responsive menu "on click"

If for example your toggle-able icon is visible only for extra small devices, then you could do something like this:

$('[data-toggle="offcanvas"]').click(function () {
    $('#side-menu').toggleClass('hidden-xs');
});

Clicking [data-toggle="offcanvas"] will add bootstrap's .hidden-xs to my #side-menu which will hide the side-menu content, but will become visible again if you increase the window size.

Including external HTML file to another HTML file

The iframe element.

<iframe src="name.html"></iframe>

But content that you way to have appear on multiple pages is better handled using templates.

How to make html table vertically scrollable

Why don't you place your table in a div?

<div style="height:100px;overflow:auto;">

 ... Your code goes here ...

</div>

String's Maximum length in Java - calling length() method

I have a 2010 iMac with 8GB of RAM, running Eclipse Neon.2 Release (4.6.2) with Java 1.8.0_25. With the VM argument -Xmx6g, I ran the following code:

StringBuilder sb = new StringBuilder();
for (int i = 0; i < Integer.MAX_VALUE; i++) {
    try {
        sb.append('a');
    } catch (Throwable e) {
        System.out.println(i);
        break;
    }
}
System.out.println(sb.toString().length());

This prints:

Requested array size exceeds VM limit
1207959550

So, it seems that the max array size is ~1,207,959,549. Then I realized that we don't actually care if Java runs out of memory: we're just looking for the maximum array size (which seems to be a constant defined somewhere). So:

for (int i = 0; i < 1_000; i++) {
    try {
        char[] array = new char[Integer.MAX_VALUE - i];
        Arrays.fill(array, 'a');
        String string = new String(array);
        System.out.println(string.length());
    } catch (Throwable e) {
        System.out.println(e.getMessage());
        System.out.println("Last: " + (Integer.MAX_VALUE - i));
        System.out.println("Last: " + i);
    }
}

Which prints:

Requested array size exceeds VM limit
Last: 2147483647
Last: 0
Requested array size exceeds VM limit
Last: 2147483646
Last: 1
Java heap space
Last: 2147483645
Last: 2

So, it seems the max is Integer.MAX_VALUE - 2, or (2^31) - 3

P.S. I'm not sure why my StringBuilder maxed out at 1207959550 while my char[] maxed out at (2^31)-3. It seems that AbstractStringBuilder doubles the size of its internal char[] to grow it, so that probably causes the issue.

Django CSRF check failing with an Ajax POST request

The issue is because django is expecting the value from the cookie to be passed back as part of the form data. The code from the previous answer is getting javascript to hunt out the cookie value and put it into the form data. Thats a lovely way of doing it from a technical point of view, but it does look a bit verbose.

In the past, I have done it more simply by getting the javascript to put the token value into the post data.

If you use {% csrf_token %} in your template, you will get a hidden form field emitted that carries the value. But, if you use {{ csrf_token }} you will just get the bare value of the token, so you can use this in javascript like this....

csrf_token = "{{ csrf_token }}";

Then you can include that, with the required key name in the hash you then submit as the data to the ajax call.

How to grab substring before a specified character jQuery or JavaScript

You can also use shift().

var streetaddress = addy.split(',').shift();

According to MDN Web Docs:

The shift() method removes the first element from an array and returns that removed element. This method changes the length of the array.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/shift

Does Google Chrome work with Selenium IDE (as Firefox does)?

If you want to harness Selenium IDE record & playback capabilities for Chrome browser there is an equivalent extension for Chrome called Scirocco. You can add it to Chrome by visiting here using your Chrome browser https://chrome.google.com/webstore/search/scirocco

Scirocco is created by Sonix Asia and is not as polished as Selenium IDE for Firefox. It is in fact quite buggy in places. But it does what you ask.

Convert object to JSON string in C#

I have used Newtonsoft JSON.NET (Documentation) It allows you to create a class / object, populate the fields, and serialize as JSON.

public class ReturnData 
{
    public int totalCount { get; set; }
    public List<ExceptionReport> reports { get; set; }  
}

public class ExceptionReport
{
    public int reportId { get; set; }
    public string message { get; set; }  
}


string json = JsonConvert.SerializeObject(myReturnData);

Convert varchar into datetime in SQL Server

I had luck with something similar:

Convert(DATETIME, CONVERT(VARCHAR(2), @Month) + '/' + CONVERT(VARCHAR(2), @Day)
+ '/' + CONVERT(VARCHAR(4), @Year))

How do you do relative time in Rails?

I've written a gem that does this for Rails ActiveRecord objects. The example uses created_at, but it will also work on updated_at or anything with the class ActiveSupport::TimeWithZone.

Just gem install and call the 'pretty' method on your TimeWithZone instance.

https://github.com/brettshollenberger/hublot

Passing multiple values for same variable in stored procedure

Your stored procedure is designed to accept a single parameter, Arg1List. You can't pass 4 parameters to a procedure that only accepts one.

To make it work, the code that calls your procedure will need to concatenate your parameters into a single string of no more than 3000 characters and pass it in as a single parameter.

How read Doc or Docx file in java?

Here is the code of ReadDoc/docx.java: This will read a dox/docx file and print its content to the console. you can customize it your way.

import java.io.*;
import org.apache.poi.hwpf.HWPFDocument;
import org.apache.poi.hwpf.extractor.WordExtractor;

public class ReadDocFile
{
    public static void main(String[] args)
    {
        File file = null;
        WordExtractor extractor = null;
        try
        {

            file = new File("c:\\New.doc");
            FileInputStream fis = new FileInputStream(file.getAbsolutePath());
            HWPFDocument document = new HWPFDocument(fis);
            extractor = new WordExtractor(document);
            String[] fileData = extractor.getParagraphText();
            for (int i = 0; i < fileData.length; i++)
            {
                if (fileData[i] != null)
                    System.out.println(fileData[i]);
            }
        }
        catch (Exception exep)
        {
            exep.printStackTrace();
        }
    }
}

How do I set ANDROID_SDK_HOME environment variable?

from command prompt:

set ANDROID_SDK_HOME=C:\[wherever your sdk folder is]

should do the trick.

Provide static IP to docker containers via docker-compose

Note that I don't recommend a fixed IP for containers in Docker unless you're doing something that allows routing from outside to the inside of your container network (e.g. macvlan). DNS is already there for service discovery inside of the container network and supports container scaling. And outside the container network, you should use exposed ports on the host. With that disclaimer, here's the compose file you want:

version: '2'

services:
  mysql:
    container_name: mysql
    image: mysql:latest
    restart: always
    environment:
      - MYSQL_ROOT_PASSWORD=root
    ports:
     - "3306:3306"
    networks:
      vpcbr:
        ipv4_address: 10.5.0.5

  apigw-tomcat:
    container_name: apigw-tomcat
    build: tomcat/.
    ports:
     - "8080:8080"
     - "8009:8009"
    networks:
      vpcbr:
        ipv4_address: 10.5.0.6
    depends_on:
     - mysql

networks:
  vpcbr:
    driver: bridge
    ipam:
     config:
       - subnet: 10.5.0.0/16
         gateway: 10.5.0.1

Environment variables in Eclipse

I was able to set the env. variables by sourcing (source command inside the shell (ksh) scirpt) the file that was settign them. Then I called the .ksh script from the external Tools

Setting unique Constraint with fluent API?

On EF6.2, you can use HasIndex() to add indexes for migration through fluent API.

https://github.com/aspnet/EntityFramework6/issues/274

Example

modelBuilder
    .Entity<User>()
    .HasIndex(u => u.Email)
        .IsUnique();

On EF6.1 onwards, you can use IndexAnnotation() to add indexes for migration in your fluent API.

http://msdn.microsoft.com/en-us/data/jj591617.aspx#PropertyIndex

You must add reference to:

using System.Data.Entity.Infrastructure.Annotations;

Basic Example

Here is a simple usage, adding an index on the User.FirstName property

modelBuilder 
    .Entity<User>() 
    .Property(t => t.FirstName) 
    .HasColumnAnnotation(IndexAnnotation.AnnotationName, new IndexAnnotation(new IndexAttribute()));

Practical Example:

Here is a more realistic example. It adds a unique index on multiple properties: User.FirstName and User.LastName, with an index name "IX_FirstNameLastName"

modelBuilder 
    .Entity<User>() 
    .Property(t => t.FirstName) 
    .IsRequired()
    .HasMaxLength(60)
    .HasColumnAnnotation(
        IndexAnnotation.AnnotationName, 
        new IndexAnnotation(
            new IndexAttribute("IX_FirstNameLastName", 1) { IsUnique = true }));

modelBuilder 
    .Entity<User>() 
    .Property(t => t.LastName) 
    .IsRequired()
    .HasMaxLength(60)
    .HasColumnAnnotation(
        IndexAnnotation.AnnotationName, 
        new IndexAnnotation(
            new IndexAttribute("IX_FirstNameLastName", 2) { IsUnique = true }));

Found shared references to a collection org.hibernate.HibernateException

Consider an entity:

public class Foo{
private<user> user;
/* with getters and setters */
}

And consider an Business Logic class:

class Foo1{
List<User> user = new ArrayList<>();
user = foo.getUser();
}

Here the user and foo.getUser() share the same reference. But saving the two references creates a conflict.

The proper usage should be:

class Foo1 {
List<User> user = new ArrayList<>();
user.addAll(foo.getUser);
}

This avoids the conflict.

How to get the background color code of an element in hex?

This Solution utilizes part of what @Newred and @Radu Di?a said. But will work in less standard cases.

 $(this).attr('style').split(';').filter(item => item.startsWith('background-color'))[0].split(":")[1].replace(/\s/g, '');

The issue both of them have is that neither check for a space between background-color: and the color.

All of these will match with the above code.

 background-color: #ffffff
 background-color:      #fffff;
 background-color:#fffff;

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

onChange is when something within a field changes eg, you write something in a text input.

onBlur is when you take focus away from a field eg, you were writing in a text input and you have clicked off it.

So really they are almost the same thing but for onChange to behave the way onBlur does something in that input needs to change.

What are .NET Assemblies?

See this:

In the Microsoft .NET framework, an assembly is a partially compiled code library for use in deployment, versioning and security

Getting Excel to refresh data on sheet from within VBA

I had an issue with turning off a background image (a DRAFT watermark) in VBA. My change wasn't showing up (which was performed with the Sheets(1).PageSetup.CenterHeader = "" method) - so I needed a way to refresh. The ActiveSheet.EnableCalculation approach partly did the trick, but didn't cover unused cells.

In the end I found what I needed with a one liner that made the image vanish when it was no longer set :-

Application.ScreenUpdating = True

Uri content://media/external/file doesn't exist for some devices

Most probably it has to do with caching on the device. Catching the exception and ignoring is not nice but my problem was fixed and it seems to work.

How to count lines of Java code using IntelliJ IDEA?

You can to use Count Lines of Code (CLOC)

On Settings -> External Tools add a new tool

  • Name: Count Lines of Code
  • Group: Statistics
  • Program: path/to/cloc
  • Parameters: $ProjectFileDir$ or $FileParentDir$

How to make the division of 2 ints produce a float instead of another int?

You can cast the numerator or the denominator to float...

int operations usually return int, so you have to change one of the operanding numbers.

Vertical align middle with Bootstrap responsive grid

Add !important rule to display: table of your .v-center class.

.v-center {
    display:table !important;
    border:2px solid gray;
    height:300px;
}

Your display property is being overridden by bootstrap to display: block.

Example

psql: FATAL: database "<user>" does not exist

As the createdb documentation states:

The first database is always created by the initdb command when the data storage area is initialized... This database is called postgres.

So if certain OS/postgresql distributions do that differently, it is certainly not the default/standard (just verified that initdb on openSUSE 13.1 creates the DB "postgres", but not "<user>"). Long story short, psql -d postgres is expected to be used when using a user other than "postgres".

Obviously the accepted answer, running createdb to create a DB named like the user, works as well, but creates a superfluous DB.

How to append a newline to StringBuilder

You can also use the line separator character in String.format (See java.util.Formatter), which is also platform agnostic.

i.e.:

result.append(String.format("%n", ""));

If you need to add more line spaces, just use:

result.append(String.format("%n%n", ""));

You can also use StringFormat to format your entire string, with a newline(s) at the end.

result.append(String.format("%10s%n%n", "This is my string."));

How to read GET data from a URL using JavaScript?

Iv'e fixed/improved Tomalak's answer with:

  • Make an Array only if needed.
  • If there's another equation symbol in the value it gets inside the value
  • It now uses the location.search value instead of a url.
  • Empty search string results in an empty object.

Code:

function getSearchObject() {
    if (location.search === "") return {};

    var o = {},
        nvPairs = location.search.substr(1).replace(/\+/g, " ").split("&");

    nvPairs.forEach( function (pair) {
        var e = pair.indexOf('=');
        var n = decodeURIComponent(e < 0 ? pair : pair.substr(0,e)),
            v = (e < 0 || e + 1 == pair.length) 
                ? null : 
                decodeURIComponent(pair.substr(e + 1,pair.length - e));
        if (!(n in o))
            o[n] = v;
        else if (o[n] instanceof Array)
            o[n].push(v);
        else
            o[n] = [o[n] , v];
    });
    return o;
}

How to build an android library with Android Studio and gradle?

Note: This answer is a pure Gradle answer, I use this in IntelliJ on a regular basis but I don't know how the integration is with Android Studio. I am a believer in knowing what is going on for me, so this is how I use Gradle and Android.

TL;DR Full Example - https://github.com/ethankhall/driving-time-tracker/

Disclaimer: This is a project I am/was working on.

Gradle has a defined structure ( that you can change, link at the bottom tells you how ) that is very similar to Maven if you have ever used it.

Project Root
+-- src
|   +-- main (your project)
|   |   +-- java (where your java code goes)
|   |   +-- res  (where your res go)
|   |   +-- assets (where your assets go)
|   |   \-- AndroidManifest.xml
|   \-- instrumentTest (test project)
|       \-- java (where your java code goes)
+-- build.gradle
\-- settings.gradle

If you only have the one project, the settings.gradle file isn't needed. However you want to add more projects, so we need it.

Now let's take a peek at that build.gradle file. You are going to need this in it (to add the android tools)

build.gradle

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.3'
    }
}

Now we need to tell Gradle about some of the Android parts. It's pretty simple. A basic one (that works in most of my cases) looks like the following. I have a comment in this block, it will allow me to specify the version name and code when generating the APK.

build.gradle

apply plugin: "android"
android {
        compileSdkVersion 17
        /*
        defaultConfig {
            versionCode = 1
            versionName = "0.0.0"
        }
        */
    }

Something we are going to want to add, to help out anyone that hasn't seen the light of Gradle yet, a way for them to use the project without installing it.

build.gradle

task wrapper(type: org.gradle.api.tasks.wrapper.Wrapper) {
    gradleVersion = '1.4'
}

So now we have one project to build. Now we are going to add the others. I put them in a directory, maybe call it deps, or subProjects. It doesn't really matter, but you will need to know where you put it. To tell Gradle where the projects are you are going to need to add them to the settings.gradle.

Directory Structure:

Project Root
+-- src (see above)
+-- subProjects (where projects are held)
|   +-- reallyCoolProject1 (your first included project)
|       \-- See project structure for a normal app
|   \-- reallyCoolProject2 (your second included project)
|       \-- See project structure for a normal app
+-- build.gradle
\-- settings.gradle

settings.gradle:

include ':subProjects:reallyCoolProject1'
include ':subProjects:reallyCoolProject2'

The last thing you should make sure of is the subProjects/reallyCoolProject1/build.gradle has apply plugin: "android-library" instead of apply plugin: "android".

Like every Gradle project (and Maven) we now need to tell the root project about it's dependency. This can also include any normal Java dependencies that you want.

build.gradle

dependencies{
    compile 'com.fasterxml.jackson.core:jackson-core:2.1.4'
    compile 'com.fasterxml.jackson.core:jackson-databind:2.1.4'
    compile project(":subProjects:reallyCoolProject1")
    compile project(':subProjects:reallyCoolProject2')
}

I know this seems like a lot of steps, but they are pretty easy once you do it once or twice. This way will also allow you to build on a CI server assuming you have the Android SDK installed there.

NDK Side Note: If you are going to use the NDK you are going to need something like below. Example build.gradle file can be found here: https://gist.github.com/khernyo/4226923

build.gradle

task copyNativeLibs(type: Copy) {
    from fileTree(dir: 'libs', include: '**/*.so' )  into  'build/native-libs'
}
tasks.withType(Compile) { compileTask -> compileTask.dependsOn copyNativeLibs }

clean.dependsOn 'cleanCopyNativeLibs'

tasks.withType(com.android.build.gradle.tasks.PackageApplication) { pkgTask ->
  pkgTask.jniDir new File('build/native-libs')
}

Sources:

  1. http://tools.android.com/tech-docs/new-build-system/user-guide
  2. https://gist.github.com/khernyo/4226923
  3. https://github.com/ethankhall/driving-time-tracker/

how does Array.prototype.slice.call() work?

I'm just writing this to remind myself...

    Array.prototype.slice.call(arguments);
==  Array.prototype.slice(arguments[1], arguments[2], arguments[3], ...)
==  [ arguments[1], arguments[2], arguments[3], ... ]

Or just use this handy function $A to turn most things into an array.

function hasArrayNature(a) {
    return !!a && (typeof a == "object" || typeof a == "function") && "length" in a && !("setInterval" in a) && (Object.prototype.toString.call(a) === "[object Array]" || "callee" in a || "item" in a);
}

function $A(b) {
    if (!hasArrayNature(b)) return [ b ];
    if (b.item) {
        var a = b.length, c = new Array(a);
        while (a--) c[a] = b[a];
        return c;
    }
    return Array.prototype.slice.call(b);
}

example usage...

function test() {
    $A( arguments ).forEach( function(arg) {
        console.log("Argument: " + arg);
    });
}

Are there pointers in php?

Yes there is something similar to pointers in PHP but may not match with what exactly happens in c or c++. Following is one of the example.

$a = "test";
$b = "a";
echo $a;
echo $b;
echo $$b;

//output
test
a
test

This illustrates similar concept of pointers in PHP.

How do I get video durations with YouTube API version 3?

I wrote the following class to get YouTube video duration using the YouTube API v3 (it returns thumbnails as well):

class Youtube
{
    static $api_key = '<API_KEY>';
    static $api_base = 'https://www.googleapis.com/youtube/v3/videos';
    static $thumbnail_base = 'https://i.ytimg.com/vi/';

    // $vid - video id in youtube
    // returns - video info
    public static function getVideoInfo($vid)
    {
        $params = array(
            'part' => 'contentDetails',
            'id' => $vid,
            'key' => self::$api_key,
        );

        $api_url = Youtube::$api_base . '?' . http_build_query($params);
        $result = json_decode(@file_get_contents($api_url), true);

        if(empty($result['items'][0]['contentDetails']))
            return null;
        $vinfo = $result['items'][0]['contentDetails'];

        $interval = new DateInterval($vinfo['duration']);
        $vinfo['duration_sec'] = $interval->h * 3600 + $interval->i * 60 + $interval->s;

        $vinfo['thumbnail']['default']       = self::$thumbnail_base . $vid . '/default.jpg';
        $vinfo['thumbnail']['mqDefault']     = self::$thumbnail_base . $vid . '/mqdefault.jpg';
        $vinfo['thumbnail']['hqDefault']     = self::$thumbnail_base . $vid . '/hqdefault.jpg';
        $vinfo['thumbnail']['sdDefault']     = self::$thumbnail_base . $vid . '/sddefault.jpg';
        $vinfo['thumbnail']['maxresDefault'] = self::$thumbnail_base . $vid . '/maxresdefault.jpg';

        return $vinfo;
    }
}

Please note that you'll need API_KEY to use the YouTube API:

  1. Create a new project here: https://console.developers.google.com/project
  2. Enable "YouTube Data API" under "APIs & auth" -> APIs
  3. Create a new server key under "APIs & auth" -> Credentials

Get the selected value in a dropdown using jQuery.

Hello guys i am using this technique to get the values from the selected dropdown list and it is working like charm.

var methodvalue = $("#method option:selected").val(); 

Open a URL without using a browser from a batch file

Not sure whether you have already gotten your owner solution. I have been using the following powshell command to achieve it:

powershell.exe -noprofile -command "Invoke-WebRequest -Uri http://your_url"

Django: ImproperlyConfigured: The SECRET_KEY setting must not be empty

To throw another potential solution into the mix, I had a settings folder as well as a settings.py in my project dir. (I was switching back from environment-based settings files to one file. I have since reconsidered.)

Python was getting confused about whether I wanted to import project/settings.py or project/settings/__init__.py. I removed the settings dir and everything now works fine.

Uninstalling Android ADT

The only way to remove the ADT plugin from Eclipse is to go to Help > About Eclipse/About ADT > Installation Details.

Select a plug-in you want to uninstall, then click Uninstall... button at the bottom.

enter image description here

If you cannot remove ADT from this location, then your best option is probably to start fresh with a clean Eclipse install.

Selecting the last value of a column

Actually I found a simpler solution here:

http://www.google.com/support/forum/p/Google+Docs/thread?tid=20f1741a2e663bca&hl=en

It looks like this:

=FILTER( A10:A100 , ROW(A10:A100) =MAX( FILTER( ArrayFormula(ROW(A10:A100)) , NOT(ISBLANK(A10:A100)))))

MSBuild doesn't copy references (DLL files) if using project dependencies in solution

Another scenario where this shows up is if you are using the older "Web Site" project type in Visual Studio. For that project type, it is unable to reference .dlls that are outside of it's own directory structure (current folder and down). So in the answer above, let's say your directory structure looks like this:

enter image description here

Where ProjectX and ProjectY are parent/child directories, and ProjectX references A.dll which in turn references B.dll, and B.dll is outside the directory structure, such as in a Nuget package on the root (Packages), then A.dll will be included, but B.dll will not.

Is there a command like "watch" or "inotifywait" on the Mac?

Facebook's watchman, available via Homebrew, also looks nice. It supports also filtering:

These two lines establish a watch on a source directory and then set up a trigger named "buildme" that will run a tool named "minify-css" whenever a CSS file is changed. The tool will be passed a list of the changed filenames.

$ watchman watch ~/src

$ watchman -- trigger ~/src buildme '*.css' -- minify-css

Notice that the path must be absolute.

how to add picasso library in android studio

easiest way to add dependence

hope this help you or Ctrl + Alt + Shift + S => select Dependencies tab and find what you need ( see my image)

Parsing JSON array with PHP foreach

$user->data is an array of objects. Each element in the array has a name and value property (as well as others).

Try putting the 2nd foreach inside the 1st.

foreach($user->data as $mydata)
{
    echo $mydata->name . "\n";
    foreach($mydata->values as $values)
    {
        echo $values->value . "\n";
    }
}

What is the difference between XML and XSD?

XSD:
XSD (XML Schema Definition) specifies how to formally describe the elements in an Extensible Markup Language (XML) document.
Xml:
XML was designed to describe data.It is independent from software as well as hardware.
It enhances the following things.
-Data sharing.
-Platform independent.
-Increasing the availability of Data.

Differences:

  1. XSD is based and written on XML.

  2. XSD defines elements and structures that can appear in the document, while XML does not.

  3. XSD ensures that the data is properly interpreted, while XML does not.

  4. An XSD document is validated as XML, but the opposite may not always be true.

  5. XSD is better at catching errors than XML.

An XSD defines elements that can be used in the documents, relating to the actual data with which it is to be encoded.
for eg:
A date that is expressed as 1/12/2010 can either mean January 12 or December 1st. Declaring a date data type in an XSD document, ensures that it follows the format dictated by XSD.

Pandas get the most frequent values of a column

Here's one way:

df['name'].value_counts()[df['name'].value_counts() == df['name'].value_counts().max()]

which prints:

helen    2
alex     2
Name: name, dtype: int64