Programs & Examples On #Param


How Exactly Does @param Work - Java

It is basically a comment. As we know, a number of people working on the same project must have knowledge about the code changes. We are making some notes in the program about the parameters.

Extract Number from String in Python

Above solutions seem to assume integers. Here's a minor modification to allow decimals:

num = float("".join(filter(lambda d: str.isdigit(d) or d == '.', inputString)

(Doesn't account for - sign, and assumes any period is properly placed in digit string, not just some english-language period lying around. It's not built to be indestructible, but worked for my data case.)

Using Git, show all commits that are in one branch, but not the other(s)

Show commits and commit contents from other-branch that are not in your current branch:

git show @..other-branch

Additionally you can apply the commits from other-branch directly to your current branch:

git cherry-pick @..other-branch

How to wrap text using CSS?



I have taken my example from a couple different websites on google. I have tested this on ff 5.0, IE 8.0, and Chrome 10. It works on all of them.

.wrapword {
    white-space: -moz-pre-wrap !important;  /* Mozilla, since 1999 */
    white-space: -pre-wrap;      /* Opera 4-6 */
    white-space: -o-pre-wrap;    /* Opera 7 */
    white-space: pre-wrap;       /* css-3 */
    word-wrap: break-word;       /* Internet Explorer 5.5+ */
    white-space: -webkit-pre-wrap; /* Newer versions of Chrome/Safari*/
    word-break: break-all;
    white-space: normal;

<table style="table-layout:fixed; width:400px">
        <td class="wrapword"></td>

Official reasons for "Software caused connection abort: socket write error"

Have you checked the Tomcat source code and the JVM source ? That may give you more help.

I think your general thinking is good. I would expect a ConnectException in the scenario that you couldn't connect. The above looks very like it's client-driven.

Finding out the name of the original repository you cloned from in Git

I stumbled on this question trying to get the organization/repo string from a git host like github or gitlab.

This is working for me:

git config --get remote.origin.url | sed -e 's/^git@.*:\([[:graph:]]*\).git/\1/'

It uses sed to replace the output of the git config command with just the organization and repo name.

Something like github/scientist would be matched by the character class [[:graph:]] in the regular expression.

The \1 tells sed to replace everything with just the matched characters.

How to Convert datetime value to yyyymmddhhmmss in SQL server?

This query is to convert the DateTimeOffset into the format yyyyMMddhhss with Offset. I have replaced the hyphens, colon(:), period(.) from the data, and kept the hyphen for the seperation of Offset from the DateTime.


save a pandas.Series histogram plot to file

Use the Figure.savefig() method, like so:

ax = s.hist()  # s is an instance of Series
fig = ax.get_figure()

It doesn't have to end in pdf, there are many options. Check out the documentation.

Alternatively, you can use the pyplot interface and just call the savefig as a function to save the most recently created figure:

import matplotlib.pyplot as plt
plt.savefig('path/to/figure.pdf')  # saves the current figure

How can I insert data into Database Laravel?

First method you can try this

$department->department_name = $request->department_name;
$department->status = $request->status;

Another way to insert records into the database with create function

$department = new Department;           
// Another Way to insert records

return redirect('admin/departments');

You need to set the filledby in Department model

namespace App;

use Illuminate\Database\Eloquent\Model;

class Department extends Model
    protected $fillable = ['department_name','status'];

UPDATE with CASE and IN - Oracle

Use to_number to convert budgpost to a number:

when to_number(budgpost,99999) in (1001,1012,50055) THEN 'BP_GR_A' 

EDIT: Make sure there are enough 9's in to_number to match to largest budget post.

If there are non-numeric budget posts, you could filter them out with a where clause at then end of the query:

where regexp_like(budgpost, '^-?[[:digit:],.]+$')

How to resolve merge conflicts in Git repository?

There are 3 steps:

  1. Find which files cause conflicts by command

    git status
  2. Check the files, in which you would find the conflicts marked like

  3. Change it to the way you want it, then commit with commands

    git add solved_conflicts_files
    git commit -m 'merge msg'

How do I create a table based on another table

There is no such syntax in SQL Server, though CREATE TABLE AS ... SELECT does exist in PDW. In SQL Server you can use this query to create an empty table:

SELECT * INTO schema.newtable FROM schema.oldtable WHERE 1 = 0;

(If you want to make a copy of the table including all of the data, then leave out the WHERE clause.)

Note that this creates the same column structure (including an IDENTITY column if one exists) but it does not copy any indexes, constraints, triggers, etc.

Open a workbook using FileDialog and manipulate it in Excel VBA

Unless I misunderstand your question, you can just open a file read only. Here is a simply example, without any checks.

To get the file path from the user use this function:

Private Function get_user_specified_filepath() As String
    'or use the other code example here.
    Dim fd As Office.FileDialog
    Set fd = Application.FileDialog(msoFileDialogFilePicker)
    fd.AllowMultiSelect = False
    fd.Title = "Please select the file."
    get_user_specified_filepath = fd.SelectedItems(1)
End Function

Then just open the file read only and assign it to a variable:

dim wb as workbook
set wb = Workbooks.Open(get_user_specified_filepath(), ReadOnly:=True)

Convert seconds value to hours minutes seconds?

This is my simple solution:

String secToTime(int sec) {
    int seconds = sec % 60;
    int minutes = sec / 60;
    if (minutes >= 60) {
        int hours = minutes / 60;
        minutes %= 60;
        if( hours >= 24) {
            int days = hours / 24;
            return String.format("%d days %02d:%02d:%02d", days,hours%24, minutes, seconds);
        return String.format("%02d:%02d:%02d", hours, minutes, seconds);
    return String.format("00:%02d:%02d", minutes, seconds);

Test Results:

Result: 00:00:36 - 36
Result: 01:00:07 - 3607
Result: 6313 days 12:39:05 - 545488745

How to delete all records from table in sqlite with Android?

    getContentResolver().delete(DB.TableName.CONTENT_URI, null, null);

How to read a single char from the console in Java (as the user types it)?

I have written a Java class RawConsoleInput that uses JNA to call operating system functions of Windows and Unix/Linux.

  • On Windows it uses _kbhit() and _getwch() from msvcrt.dll.
  • On Unix it uses tcsetattr() to switch the console to non-canonical mode, to check whether data is available and to read bytes from the console. A CharsetDecoder is used to convert bytes to characters.

It supports non-blocking input and mixing raw mode and normal line mode input.

Make a div into a link

You can't make the div a link itself, but you can make an <a> tag act as a block, the same behaviour a <div> has.

a {
    display: block;

You can then set the width and height on it.

Xcode build failure "Undefined symbols for architecture x86_64"

In my case, I built a custom framework with Deployment target set to 9.1, but the Deployment target of my app was lower, which supports 8.1. Minimize the custom framework Deployment target solved my problem.

How can I determine the character encoding of an excel file?

For Excel 2010 it should be UTF-8. Instruction by MS :

"The basic document structure of a SpreadsheetML document consists of the Sheets and Sheet elements, which reference the worksheets in the Workbook. A separate XML file is created for each Worksheet. For example, the SpreadsheetML for a workbook that has two worksheets name MySheet1 and MySheet2 is located in the Workbook.xml file and is shown in the following code example.

<?xml version="1.0" encoding="UTF-8" standalone="yes" ?> 
<workbook xmlns= xmlns:r="">
        <sheet name="MySheet1" sheetId="1" r:id="rId1" /> 
        <sheet name="MySheet2" sheetId="2" r:id="rId2" /> 

The worksheet XML files contain one or more block level elements such as SheetData. sheetData represents the cell table and contains one or more Row elements. A row contains one or more Cell elements. Each cell contains a CellValue element that represents the value of the cell. For example, the SpreadsheetML for the first worksheet in a workbook, that only has the value 100 in cell A1, is located in the Sheet1.xml file and is shown in the following code example.

<?xml version="1.0" encoding="UTF-8" ?> 
<worksheet xmlns="">
        <row r="1">
            <c r="A1">


Detection of cell encodings:

Python module for converting PDF to text

slate is a project that makes it very simple to use PDFMiner from a library:

>>> with open('example.pdf') as f:
...    doc = slate.PDF(f)
>>> doc
[..., ..., ...]
>>> doc[1]
'Text from page 2...'   

Find all table names with column name?

Please try the below query. Use sys.columns to get the details :-

SELECT AS ColName, AS TableName
FROM sys.columns c
    JOIN sys.tables t ON c.object_id = t.object_id

Downloading and unzipping a .zip file without writing to disk

write to a temporary file which resides in RAM

it turns out the tempfile module ( ) has just the thing:

tempfile.SpooledTemporaryFile([max_size=0[, mode='w+b'[, bufsize=-1[, suffix=''[, prefix='tmp'[, dir=None]]]]]])

This function operates exactly as TemporaryFile() does, except that data is spooled in memory until the file size exceeds max_size, or until the file’s fileno() method is called, at which point the contents are written to disk and operation proceeds as with TemporaryFile().

The resulting file has one additional method, rollover(), which causes the file to roll over to an on-disk file regardless of its size.

The returned object is a file-like object whose _file attribute is either a StringIO object or a true file object, depending on whether rollover() has been called. This file-like object can be used in a with statement, just like a normal file.

New in version 2.6.

or if you're lazy and you have a tmpfs-mounted /tmp on Linux, you can just make a file there, but you have to delete it yourself and deal with naming

How to change the length of a column in a SQL Server table via T-SQL

So, let's say you have this table:


And you want to change Col1 to VARCHAR(20). What you need to do is this:


That'll work without problems since the length of the column got bigger. If you wanted to change it to VARCHAR(5), then you'll first gonna need to make sure that there are not values with more chars on your column, otherwise that ALTER TABLE will fail.

Export Postgresql table data using pgAdmin

Just right click on a table and select "backup". The popup will show various options, including "Format", select "plain" and you get plain SQL.

pgAdmin is just using pg_dump to create the dump, also when you want plain SQL.

It uses something like this:

pg_dump --user user --password --format=plain --table=tablename --inserts --attribute-inserts etc.

Android open camera from button

you can use the following code

         Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);

                pic = new File(Environment.getExternalStorageDirectory(),
                        mApp.getPreference().getString(Common.u_id, "") + ".jpg");

                picUri = Uri.fromFile(pic);

                cameraIntent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, picUri);

                cameraIntent.putExtra("return-data", true);
                startActivityForResult(cameraIntent, PHOTO);

Call to undefined function oci_connect()

Download from Instant Client for Microsoft Windows (x64) and extract the files below to "c:\oracle": This will create the following folder "C:\Oracle\instantclient_12_1".

Finally, add the "C:\Oracle\instantclient_12_1" folder to the PATH enviroment variable, placing it on the leftmost place.

Then Restart your server.

Python, how to check if a result set is empty?

cursor.rowcount will usually be set to 0.

If, however, you are running a statement that would never return a result set (such as INSERT without RETURNING, or SELECT ... INTO), then you do not need to call .fetchall(); there won't be a result set for such statements. Calling .execute() is enough to run the statement.

Note that database adapters are also allowed to set the rowcount to -1 if the database adapter can't determine the exact affected count. See the PEP 249 Cursor.rowcount specification:

The attribute is -1 in case no .execute*() has been performed on the cursor or the rowcount of the last operation is cannot be determined by the interface.

The sqlite3 library is prone to doing this. In all such cases, if you must know the affected rowcount up front, execute a COUNT() select in the same transaction first.

One time page refresh after first page load

Try with this

var element = document.getElementById('position');        

Add button to a layout programmatically

If you just have included a layout file at the beginning of onCreate() inside setContentView and want to get this layout to add new elements programmatically try this:

ViewGroup linearLayout = (ViewGroup) findViewById(;

then you can create a new Button for example and just add it:

Button bt = new Button(this);
bt.setText("A Button");
bt.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, 

How to Execute a Python File in Notepad ++?

You can run your script via cmd and be in script-directory:

cmd /k cd /d $(CURRENT_DIRECTORY) && python $(FULL_CURRENT_PATH)

Adding form action in html in laravel

You can use the action() helper to generate an URL to your route:

<form method="post" action="{{ action('WelcomeController@log_in') }}" accept-charset="UTF-8">

Note that the Laravel 5 default installation already comes with views and controllers for the whole authentication process. Just go to /home on a fresh install and you should get redirected to a login page.

Also make sure to read the Authentication section in the docs

The error you're getting now (TokenMismatchException) is because Laravel has CSRF protection out of the box

To make use of it (and make the error go away) add a hidden field to your form:

<input name="_token" type="hidden" value="{{ csrf_token() }}"/>

Alternatively you can also disable CSRF protection by removing 'App\Http\Middleware\VerifyCsrfToken' from the $middleware array in app/Http/Kernel.php

PHP error: php_network_getaddresses: getaddrinfo failed: (while getting information from other site.)

In my case this was being issued by wp cli, and the problem was that I didn't have php7.3-curl installed. Fixed with: apt-get install -y --quiet php7.3-curl

How to compare two lists in python?

Given the code you provided in comments, I assume you want to do this:

>>> dateList = "Thu Sep 16 13:14:15 CDT 2010".split()
>>> sdateList = "Thu Sep 16 14:14:15 CDT 2010".split()
>>> dateList == sdataList

The split-method of the string returns a list. A list in Python is very different from an array. == in this case does an element-wise comparison of the two lists and returns if all their elements are equal and the number and order of the elements is the same. Read the documentation.

How do I parse JSON with Objective-C?

JSON parsing using NSJSONSerialization

   NSString* path  = [[NSBundle mainBundle] pathForResource:@"data" ofType:@"json"];
    //Here you can take JSON string from your URL ,I am using json file
    NSString* jsonString = [[NSString alloc] initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
    NSData* jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
    NSError *jsonError;
    NSArray *jsonDataArray = [NSJSONSerialization JSONObjectWithData:[jsonString dataUsingEncoding:NSUTF8StringEncoding] options:kNilOptions error:&jsonError];
    NSLog(@"jsonDataArray: %@",jsonDataArray);

    NSDictionary *jsonObject = [NSJSONSerialization JSONObjectWithData:jsonData options:kNilOptions error:&jsonError];
if(jsonObject !=nil){
   // NSString *errorCode=[NSMutableString stringWithFormat:@"%@",[jsonObject objectForKey:@"response"]];
        if(![[jsonObject objectForKey:@"#data"] isEqual:@""]){
            NSMutableArray *array=[jsonObject objectForKey:@"#data"];
             // NSLog(@"array: %@",array);
            NSLog(@"array: %d",array.count);  
            int k = 0;
            for(int z = 0; z<array.count;z++){
                NSString *strfd = [NSString stringWithFormat:@"%d",k];
                NSDictionary *dicr = jsonObject[@"#data"][strfd];
                // NSLog(@"dicr: %@",dicr);
                 NSLog(@"Firstname - Lastname   : %@ - %@",
                     [NSMutableString stringWithFormat:@"%@",[dicr objectForKey:@"user_first_name"]],
                     [NSMutableString stringWithFormat:@"%@",[dicr objectForKey:@"user_last_name"]]);


You can see the Console output as below :

Firstname - Lastname : Chandra Bhusan - Pandey

Firstname - Lastname : Kalaiyarasan - Balu

Firstname - Lastname : (null) - (null)

Firstname - Lastname : Girija - S

Firstname - Lastname : Girija - S

Firstname - Lastname : (null) - (null)

View a file in a different Git branch without changing branches

A simple, newbie friendly way for looking into a file: git gui browser <branch> which lets you explore the contents of any file.

It's also there in the File menu of git gui. Most other -more advanced- GUI wrappers (Qgit, Egit, etc..) offer browsing/opening files as well.

Detect click inside/outside of element with single event handler

If you want to add a click listener in chrome console, use this

document.querySelectorAll("label")[6].parentElement.onclick = () => {console.log('label clicked');}

How to set a time zone (or a Kind) of a DateTime value?

If you want to get advantage of your local machine timezone you can use myDateTime.ToUniversalTime() to get the UTC time from your local time or myDateTime.ToLocalTime() to convert the UTC time to the local machine's time.

// convert UTC time from the database to the machine's time
DateTime databaseUtcTime = new DateTime(2011,6,5,10,15,00);
var localTime = databaseUtcTime.ToLocalTime();

// convert local time to UTC for database save
var databaseUtcTime = localTime.ToUniversalTime();

If you need to convert time from/to other timezones, you may use TimeZoneInfo.ConvertTime() or TimeZoneInfo.ConvertTimeFromUtc().

// convert UTC time from the database to japanese time
DateTime databaseUtcTime = new DateTime(2011,6,5,10,15,00);
var japaneseTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Tokyo Standard Time");
var japaneseTime = TimeZoneInfo.ConvertTimeFromUtc(databaseUtcTime, japaneseTimeZone);

// convert japanese time to UTC for database save
var databaseUtcTime = TimeZoneInfo.ConvertTimeToUtc(japaneseTime, japaneseTimeZone);

List of available timezones

TimeZoneInfo class on MSDN

Efficient way to remove ALL whitespace from String?

We can use:

    public static string RemoveWhitespace(this string input)
        if (input == null)
            return null;
        return new string(input.ToCharArray()
            .Where(c => !Char.IsWhiteSpace(c))

Heap vs Binary Search Tree (BST)

As mentioned by others, Heap can do findMin or findMax in O(1) but not both in the same data structure. However I disagree that Heap is better in findMin/findMax. In fact, with a slight modification, the BST can do both findMin and findMax in O(1).

In this modified BST, you keep track of the the min node and max node everytime you do an operation that can potentially modify the data structure. For example in insert operation you can check if the min value is larger than the newly inserted value, then assign the min value to the newly added node. The same technique can be applied on the max value. Hence, this BST contain these information which you can retrieve them in O(1). (same as binary heap)

In this BST (Balanced BST), when you pop min or pop max, the next min value to be assigned is the successor of the min node, whereas the next max value to be assigned is the predecessor of the max node. Thus it perform in O(1). However we need to re-balance the tree, thus it will still run O(log n). (same as binary heap)

I would be interested to hear your thought in the comment below. Thanks :)


Cross reference to similar question Can we use binary search tree to simulate heap operation? for more discussion on simulating Heap using BST.

How to rebuild docker container in docker-compose.yml?

Simply use :

docker-compose build [yml_service_name]

Replace [yml_service_name] with your service name in docker-compose.yml file. You can use docker-compose restart to make sure changes are effected. You can use --no-cache to ignore the cache.

Apache could not be started - ServerRoot must be a valid directory and Unable to find the specified module

Just run setup_xampp.bat from shell (shell from XAMPP control panel)and the paths should be set automatically for the portable version of XAMPP for windows. It has worked for me.

Count the number of occurrences of a string in a VARCHAR field?

This should do the trick:

    ROUND (   
            - LENGTH( REPLACE ( description, "value", "") ) 
        ) / LENGTH("value")        
    ) AS count    
FROM <table> 

Using the Underscore module with Node.js

Or :

    var _ = require('underscore')._;

How to increase the distance between table columns in HTML?

You can just use padding. Like so:




 td {padding:10px 25px 10px 25px;}


 tr td:first-child {padding-left:0px;}
 td {padding:10px 0px 10px 50px;}

Using an integer as a key in an associative array in JavaScript

Get the value for an associative array property when the property name is an integer:

Starting with an associative array where the property names are integers:

var categories = [
    {"1": "Category 1"},
    {"2": "Category 2"},
    {"3": "Category 3"},
    {"4": "Category 4"}

Push items to the array:

categories.push({"2300": "Category 2300"});
categories.push({"2301": "Category 2301"});

Loop through the array and do something with the property value.

for (var i = 0; i < categories.length; i++) {
    for (var categoryid in categories[i]) {
        var category = categories[i][categoryid];
        // Log progress to the console
        console.log(categoryid + ": " + category);
        //  ... do something

Console output should look like this:

1: Category 1
2: Category 2
3: Category 3
4: Category 4
2300: Category 2300
2301: Category 2301

As you can see, you can get around the associative array limitation and have a property name be an integer.

NOTE: The associative array in my example is the JSON content you would have if you serialized a Dictionary<string, string>[] object.

Gradle DSL method not found: 'runProguard'

enter image description hereIf you are using version 0.14.0 or higher of the gradle plugin, you should replace "runProguard" with "minifyEnabled" in your build.gradle files.

runProguard was renamed to minifyEnabled in version 0.14.0. For more info, See Android Build System

javascript clear field value input

do like

<input name="name" id="name" type="text" value="Name" 
   onblur="fillField(this,'Name');" onfocus="clearField(this,'Name');"/>

and js

function fillField(input,val) {
      if(input.value == "")

function clearField(input,val) {
      if(input.value == val)


here is a demo fiddle of the same

How to compile Tensorflow with SSE4.2 and AVX instructions?


Execute the below commands in Terminal (Linux/MacOS) or in Command Prompt (Windows) to install Tensorflow 2.0 using Bazel:

git clone
cd tensorflow

#The repo defaults to the master development branch. You can also checkout a release branch to build:
git checkout r2.0

#Configure the Build => Use the Below line for Windows Machine
python ./ 

#Configure the Build => Use the Below line for Linux/MacOS Machine
#This script prompts you for the location of TensorFlow dependencies and asks for additional build configuration options. 

#Build Tensorflow package

#CPU support
bazel build --config=opt //tensorflow/tools/pip_package:build_pip_package 

#GPU support
bazel build --config=opt --config=cuda --define=no_tensorflow_py_deps=true //tensorflow/tools/pip_package:build_pip_package

How to change the background color of the options menu?

protected void setMenuBackground() {
    getLayoutInflater().setFactory(new Factory() {
        public View onCreateView (String name, Context context, AttributeSet attrs) {
            if (name.equalsIgnoreCase("")) {
                try {
                    // Ask our inflater to create the view
                    LayoutInflater f = getLayoutInflater();
                    final View view = f.createView(name, null, attrs);
                    // Kind of apply our own background
                    new Handler().post( new Runnable() {
                        public void run () {
                    return view;
                catch (InflateException e) {
                catch (ClassNotFoundException e) {
            return null;

this is XML file


How to store printStackTrace into a string

StackTraceElement[] stack = new Exception().getStackTrace();
String theTrace = "";
for(StackTraceElement line : stack)
   theTrace += line.toString();

Can PHP cURL retrieve response headers AND body in a single request?

Just set options :



and use curl_getinfo with CURLINFO_HTTP_CODE (or no opt param and you will have an associative array with all the informations you want)

More at :

Node.js res.setHeader('content-type', 'text/javascript'); pushing the response javascript as file download

Use application/javascript as content type instead of text/javascript

text/javascript is mentioned obsolete. See reference docs.

Also see this question on SO.


I have tried executing the code you have given and the below didn't work.

res.setHeader('content-type', 'text/javascript');

This is what worked for me.

res.setHeader('content-type', 'text/javascript');

As robertklep has suggested, please refer to the node http docs, there is no response.send() there.

How to Get JSON Array Within JSON Object?

Solved, use array list of string to get name from Ingredients. Use below code:

JSONObject jsonObj = new JSONObject(jsonStr);

//extracting data array from json string
JSONArray ja_data = jsonObj.getJSONArray("data");
int length = ja_data.length();

//loop to get all json objects from data json array
for(int i=0; i<length; i++){
    JSONObject jObj = ja_data.getJSONObject(i);
    Toast.makeText(this, jObj.getString("Name"), Toast.LENGTH_LONG).show();
    // getting inner array Ingredients
    JSONArray ja = jObj.getJSONArray("Ingredients");
    int len = ja.length();
    ArrayList<String> Ingredients_names = new ArrayList<>();
    for(int j=0; j<len; j++){
        JSONObject json = ja.getJSONObject(j);

Return list using select new in LINQ

What is being returned is an anonymous type so create a new class with 2 fields

class BasicProjectInfo {
   string name;
   string id;

and return new BasicProjectInfo(pro.ProjectName, pro.ProjectId);. You method in this case will return a List<BasicProjectInfo>

Route [login] not defined

Am late to the party. if your expectation is some sort of json returned other than being redirected, then edit the exception handler so do just that.

Go to go to App\Exceptions\Handler.php Then edit this code:

public function render($request, Exception $exception)
        return parent::render($request, $exception);


public function render($request, Exception $exception)
        return response()->json(
                'errors' => [
                    'status' => 401,
                    'message' => 'Unauthenticated',
            ], 401

How to sort pandas data frame using values from several columns?

I have found this to be really useful:

df = pd.DataFrame({'A' : range(0,10) * 2, 'B' : np.random.randint(20,30,20)})

# A ascending, B descending

# A descending, B ascending

Note that unlike the standard columns=,ascending= arguments, here column names and their sort order are in the same place. As a result your code gets a lot easier to read and maintain.

Note the actual call to .sort is unchanged, skw (sortkwargs) is just a small helper function that parses the columns and returns the usual columns= and ascending= parameters for you. Pass it any other sort kwargs as you usually would. Copy/paste the following code into e.g. your local then forget about it and just use it as above.

# (or anywhere else convenient to import)
def skw(columns=None, **kwargs):
    """ get sort kwargs by parsing sort order given in column name """
    # set default order as ascending (+)
    sort_cols = ['+' + col if col[0] != '-' else col for col in columns]
    # get sort kwargs
    columns, ascending = zip(*[(col.replace('+', '').replace('-', ''), 
                                False if col[0] == '-' else True) 
                               for col in sort_cols])
    kwargs.update(dict(columns=list(columns), ascending=ascending))
    return kwargs

How do you create nested dict in Python?

For arbitrary levels of nestedness:

In [2]: def nested_dict():
   ...:     return collections.defaultdict(nested_dict)

In [3]: a = nested_dict()

In [4]: a
Out[4]: defaultdict(<function __main__.nested_dict>, {})

In [5]: a['a']['b']['c'] = 1

In [6]: a
defaultdict(<function __main__.nested_dict>,
            {'a': defaultdict(<function __main__.nested_dict>,
                         {'b': defaultdict(<function __main__.nested_dict>,
                                      {'c': 1})})})

How do I specify the JDK for a GlassFish domain?

Here you can find how to set path to JDK for Glassfish:



where java path is configured

REM set AS_JAVA=C:\Program Files\Java\jdk1.6.0_04\jre/..
set AS_JAVA=C:\Program Files\Java\jdk1.5.0_16

How do I detect if I am in release or debug mode?

Due to the mixed comments about BuildConfig.DEBUG, I used the following to disable crashlytics (and analytics) in debug mode :

update /app/build.gradle

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.1"

    defaultConfig {
        applicationId ""
        minSdkVersion 16
        targetSdkVersion 25
        versionCode 100
        versionName "1.0.0"
        buildConfigField 'boolean', 'ENABLE_CRASHLYTICS', 'true'
    buildTypes {
        debug {
            debuggable true
            minifyEnabled false
            buildConfigField 'boolean', 'ENABLE_CRASHLYTICS', 'false'
        release {
            debuggable false
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), ''

then, in your code you detect the ENABLE_CRASHLYTICS flag as follows:

    if (BuildConfig.ENABLE_CRASHLYTICS)
        // enable crashlytics and answers (Crashlytics by default includes Answers)
        Fabric.with(this, new Crashlytics());

use the same concept in your app and rename ENABLE_CRASHLYTICS to anything you want. I like this approach because I can see the flag in the configuration and I can control the flag.

mysqli_fetch_array while loop columns

This one was your solution.

$x = 0;
while($row = mysqli_fetch_array($result)) {             
    $posts[$x]['post_id'] = $row['post_id'];
    $posts[$x]['post_title'] = $row['post_title'];
    $posts[$x]['type'] = $row['type'];
    $posts[$x]['author'] = $row['author'];

Python Error: unsupported operand type(s) for +: 'int' and 'NoneType'

In your giant elif chain, you skipped 13. You might want to throw an error if you hit the end of the chain without returning anything, to catch numbers you missed and incorrect calls of the function:

elif x == 90:
    return 6
    raise ValueError(x)

How to change the URI (URL) for a remote Git repository?

git remote set-url origin git://new.location

(alternatively, open .git/config, look for [remote "origin"], and edit the url = line.

You can check it worked by examining the remotes:

git remote -v
# origin  git://new.location (fetch)
# origin  git://new.location (push)

Next time you push, you'll have to specify the new upstream branch, e.g.:

git push -u origin master

See also: GitHub: Changing a remote's URL

Convert a date format in PHP

function dateFormat($date)
    $m = preg_replace('/[^0-9]/', '', $date);
    if (preg_match_all('/\d{2}+/', $m, $r)) {
        $r = reset($r);
        if (count($r) == 4) {
            if ($r[2] <= 12 && $r[3] <= 31) return "$r[0]$r[1]-$r[2]-$r[3]"; // Y-m-d
            if ($r[0] <= 31 && $r[1] != 0 && $r[1] <= 12) return "$r[2]$r[3]-$r[1]-$r[0]"; // d-m-Y
            if ($r[0] <= 12 && $r[1] <= 31) return "$r[2]$r[3]-$r[0]-$r[1]"; // m-d-Y
            if ($r[2] <= 31 && $r[3] <= 12) return "$r[0]$r[1]-$r[3]-$r[2]"; //Y-m-d

        $y = $r[2] >= 0 && $r[2] <= date('y') ? date('y') . $r[2] : (date('y') - 1) . $r[2];
        if ($r[0] <= 31 && $r[1] != 0 && $r[1] <= 12) return "$y-$r[1]-$r[0]"; // d-m-y

var_dump(dateFormat('31/01/00')); // return 2000-01-31
var_dump(dateFormat('31/01/2000')); // return 2000-01-31
var_dump(dateFormat('01-31-2000')); // return 2000-01-31
var_dump(dateFormat('2000-31-01')); // return 2000-01-31
var_dump(dateFormat('20003101')); // return 2000-01-31

ping: Temporary failure in name resolution

I've faced the exactly same problem but I've fixed it with another approache.

Using Ubuntu 18.04, first disable systemd-resolved service.

sudo systemctl disable systemd-resolved.service

Stop the service

sudo systemctl stop systemd-resolved.service

Then, remove the link to /run/systemd/resolve/stub-resolv.conf in /etc/resolv.conf

sudo rm /etc/resolv.conf

Add a manually created resolv.conf in /etc/

sudo vim /etc/resolv.conf

Add your prefered DNS server there


I've tested this with success.

Defining a variable with or without export

export NAME=value for settings and variables that have meaning to a subprocess.

NAME=value for temporary or loop variables private to the current shell process.

In more detail, export marks the variable name in the environment that copies to a subprocesses and their subprocesses upon creation. No name or value is ever copied back from the subprocess.

  • A common error is to place a space around the equal sign:

    $ export FOO = "bar"  
    bash: export: `=': not a valid identifier
  • Only the exported variable (B) is seen by the subprocess:

    $ A="Alice"; export B="Bob"; echo "echo A is \$A. B is \$B" | bash
    A is . B is Bob
  • Changes in the subprocess do not change the main shell:

    $ export B="Bob"; echo 'B="Banana"' | bash; echo $B
  • Variables marked for export have values copied when the subprocess is created:

    $ export B="Bob"; echo '(sleep 30; echo "Subprocess 1 has B=$B")' | bash &
    [1] 3306
    $ B="Banana"; echo '(sleep 30; echo "Subprocess 2 has B=$B")' | bash 
    Subprocess 1 has B=Bob
    Subprocess 2 has B=Banana
    [1]+  Done         echo '(sleep 30; echo "Subprocess 1 has B=$B")' | bash
  • Only exported variables become part of the environment (man environ):

     $ ALICE="Alice"; export BOB="Bob"; env | grep "ALICE\|BOB"

So, now it should be as clear as is the summer's sun! Thanks to Brain Agnew, alexp, and William Prusell.

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

The reason for the exception is that and implicitly calls bool. First on the left operand and (if the left operand is True) then on the right operand. So x and y is equivalent to bool(x) and bool(y).

However the bool on a numpy.ndarray (if it contains more than one element) will throw the exception you have seen:

>>> import numpy as np
>>> arr = np.array([1, 2, 3])
>>> bool(arr)
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

The bool() call is implicit in and, but also in if, while, or, so any of the following examples will also fail:

>>> arr and arr
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

>>> if arr: pass
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

>>> while arr: pass
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

>>> arr or arr
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

There are more functions and statements in Python that hide bool calls, for example 2 < x < 10 is just another way of writing 2 < x and x < 10. And the and will call bool: bool(2 < x) and bool(x < 10).

The element-wise equivalent for and would be the np.logical_and function, similarly you could use np.logical_or as equivalent for or.

For boolean arrays - and comparisons like <, <=, ==, !=, >= and > on NumPy arrays return boolean NumPy arrays - you can also use the element-wise bitwise functions (and operators): np.bitwise_and (& operator)

>>> np.logical_and(arr > 1, arr < 3)
array([False,  True, False], dtype=bool)

>>> np.bitwise_and(arr > 1, arr < 3)
array([False,  True, False], dtype=bool)

>>> (arr > 1) & (arr < 3)
array([False,  True, False], dtype=bool)

and bitwise_or (| operator):

>>> np.logical_or(arr <= 1, arr >= 3)
array([ True, False,  True], dtype=bool)

>>> np.bitwise_or(arr <= 1, arr >= 3)
array([ True, False,  True], dtype=bool)

>>> (arr <= 1) | (arr >= 3)
array([ True, False,  True], dtype=bool)

A complete list of logical and binary functions can be found in the NumPy documentation:

Resize Google Maps marker icon image

MarkerImage has been deprecated for Icon

Until version 3.10 of the Google Maps JavaScript API, complex icons were defined as MarkerImage objects. The Icon object literal was added in 3.10, and replaces MarkerImage from version 3.11 onwards. Icon object literals support the same parameters as MarkerImage, allowing you to easily convert a MarkerImage to an Icon by removing the constructor, wrapping the previous parameters in {}'s, and adding the names of each parameter.

Phillippe's code would now be:

 var icon = {
     url: "../res/sit_marron.png", // url
     scaledSize: new google.maps.Size(width, height), // size
     origin: new google.maps.Point(0,0), // origin
     anchor: new google.maps.Point(anchor_left, anchor_top) // anchor 

 position = new google.maps.LatLng(latitud,longitud)
 marker = new google.maps.Marker({
  position: position,
  map: map,
  icon: icon

How can a windows service programmatically restart itself?

The problem with shelling out to a batch file or EXE is that a service may or may not have the permissions required to run the external app.

The cleanest way to do this that I have found is to use the OnStop() method, which is the entry point for the Service Control Manager. Then all your cleanup code will run, and you won't have any hanging sockets or other processes, assuming your stop code is doing its job.

To do this you need to set a flag before you terminate that tells the OnStop method to exit with an error code; then the SCM knows that the service needs to be restarted. Without this flag you won't be able to stop the service manually from the SCM. This also assumes you have set up the service to restart on an error.

Here's my stop code:


bool ABORT;

protected override void OnStop()
    Logger.log("Stopping service");
    WorkThreadRun = false;
    // if there was a problem, set an exit error code
    // so the service manager will restart this

If the service runs into a problem and needs to restart, I launch a thread that stops the service from the SCM. This allows the service to clean up after itself:


    ABORT = true;
    new Thread(RestartThread).Start();

void RestartThread()
    ServiceController sc = new ServiceController(ServiceName);
    catch (Exception) { }

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

I wouldn't recommend any of these methods. Instead, put it within its own namespace.

class Post < ActiveRecord::Base
  def clean_input
    self.input = Helpers.sanitize(self.input, :tags => %w(b i u))

  module Helpers
    extend ActionView::Helpers::SanitizeHelper

Entity Framework 5 Updating a Record

foreach(PropertyInfo propertyInfo in original.GetType().GetProperties()) {
    if (propertyInfo.GetValue(updatedUser, null) == null)
        propertyInfo.SetValue(updatedUser, propertyInfo.GetValue(original, null), null);

jquery find element by specific class when element has multiple classes

An element can have any number of classNames, however, it can only have one class attribute; only the first one will be read by jQuery.

Using the code you posted, $(".alert-box.warn") will work but $(".alert-box.dead") will not.

Adding placeholder text to textbox

This would mean you have a button which allows you to do an action, such as logging in or something. Before you do the action you check if the textbox is filled in. If not it will replace the text

 private void button_Click(object sender, EventArgs e)
     string textBoxText = textBox.Text;

     if (String.IsNullOrWhiteSpace(textBoxText))
         textBox.Text = "Fill in the textbox";

 private void textBox_Enter(object sender, EventArgs e)
     TextBox currentTextbox = sender as TextBox;
     if (currentTextbox.Text == "Fill in the textbox")
         currentTextbox.Text = "";

It's kind of cheesy but checking the text for the value you're giving it is the best I can do atm, not that good at c# to get a better solution.

How to access remote server with local phpMyAdmin client?

You can set in the file of your phpMyAdmin installation.

$cfg['Servers'][$i]['host'] = '';

Do you use source control for your database items?

This has always been a big annoyance for me too - it seems like it is just way too easy to make a quick change to your development database, save it (forgetting to save a change script), and then you're stuck. You could undo what you just did and redo it to create the change script, or write it from scratch if you want of course too, though that's a lot of time spent writing scripts.

A tool that I have used in the past that has helped with this some is SQL Delta. It will show you the differences between two databases (SQL server/Oracle I believe) and generate all the change scripts necessary to migrate A->B. Another nice thing it does is show all the differences between database content between the production (or test) DB and your development DB. Since more and more apps store configuration and state that is crucial to their execution in database tables, it can be a real pain to have change scripts that remove, add, and alter the proper rows. SQL Delta shows the rows in the database just like they would look in a Diff tool - changed, added, deleted.

An excellent tool. Here is the link:

How can I return the sum and average of an int array?

You have tried the wrong variable, ints is not the correct name of the argument.

public int Sum(params int[] customerssalary)
    return customerssalary.Sum();

public double Avg(params int[] customerssalary)
    return customerssalary.Average();

But do you think that these methods are really needed?

Hbase quickly count number of rows

You can use coprocessor what is available since HBase 0.92. See Coprocessor and AggregateProtocol and example

How to highlight cell if value duplicate in same column for google spreadsheet?

Try this:

  1. Select the whole column
  2. Click Format
  3. Click Conditional formatting
  4. Click Add another rule (or edit the existing/default one)
  5. Set Format cells if to: Custom formula is
  6. Set value to: =countif(A:A,A1)>1 (or change A to your chosen column)
  7. Set the formatting style.
  8. Ensure the range applies to your column (e.g., A1:A100).
  9. Click Done

Anything written in the A1:A100 cells will be checked, and if there is a duplicate (occurs more than once) then it'll be coloured.

For locales using comma (,) as a decimal separator, the argument separator is most likely a semi-colon (;). That is, try: =countif(A:A;A1)>1, instead.

For multiple columns, use countifs.

Groovy - Convert object to JSON string

Do you mean like:

import groovy.json.*

class Me {
    String name

def o = new Me( name: 'tim' )

println new JsonBuilder( o ).toPrettyString()

Calculate the date yesterday in JavaScript

If you want to both get the date for yesterday and format that date in a human readable format, consider creating a custom DateHelper object that looks something like this :

var DateHelper = {_x000D_
    addDays : function(aDate, numberOfDays) {_x000D_
        aDate.setDate(aDate.getDate() + numberOfDays); // Add numberOfDays_x000D_
        return aDate;                                  // Return the date_x000D_
    format : function format(date) {_x000D_
        return [_x000D_
           ("0" + date.getDate()).slice(-2),           // Get day and pad it with zeroes_x000D_
           ("0" + (date.getMonth()+1)).slice(-2),      // Get month and pad it with zeroes_x000D_
           date.getFullYear()                          // Get full year_x000D_
        ].join('/');                                   // Glue the pieces together_x000D_
// With this helper, you can now just use one line of readable code to :_x000D_
// ---------------------------------------------------------------------_x000D_
// 1. Get the current date_x000D_
// 2. Subtract 1 day_x000D_
// 3. Format it_x000D_
// 4. Output it_x000D_
// ---------------------------------------------------------------------_x000D_
document.body.innerHTML = DateHelper.format(DateHelper.addDays(new Date(), -1));

(see also this Fiddle)

Getting content/message from HttpResponseMessage

I think the following image helps for those needing to come by T as the return type.

enter image description here

How can one create an overlay in css?

I'm late to the party, but if you want to do this to an arbitrary element using only CSS, without messing around with positioning, overlay divs etc., you can use an inset box shadow:

box-shadow: inset 0px 0px 0 2000px rgba(0,0,0,0.5);

This will work on any element smaller than 4000 pixels long or wide.


How to append binary data to a buffer in node.js

insert byte to specific place.

insertToArray(arr,index,item) {
   return Buffer.concat([arr.slice(0,index),Buffer.from(item,"utf-8"),arr.slice(index)]);

Convert a space delimited string to list

states_list = states.split(' ')

In regards to your edit:

from random import choice
random_state = choice(states_list)

Font size relative to the user's screen resolution?

You might try this tool:

I haven't used this second tool, but it seems similar:

Using dig to search for SPF records

The dig utility is pretty convenient to use. The order of the arguments don't really matter.I'll show you some easy examples.
To get all root name servers use

# dig

To get a TXT record of a specific host use

# dig txt
# dig txt

To query a specific name server just add @nameserver.tld

# dig txt

The SPF RFC4408 says that SPF records can be stored as SPF or TXT. However nearly all use only TXT records at the moment. So you are pretty safe if you only fetch TXT records.

I made a SPF checker for visualising the SPF records of a domain. It might help you to understand SPF records better. You can find it here:

Objective-C: Reading a file line by line

To read a file line by line (also for extreme big files) can be done by the following functions:

DDFileReader * reader = [[DDFileReader alloc] initWithFilePath:pathToMyFile];
NSString * line = nil;
while ((line = [reader readLine])) {
  NSLog(@"read line: %@", line);
[reader release];


DDFileReader * reader = [[DDFileReader alloc] initWithFilePath:pathToMyFile];
[reader enumerateLinesUsingBlock:^(NSString * line, BOOL * stop) {
  NSLog(@"read line: %@", line);
[reader release];

The class DDFileReader that enables this is the following:

Interface File (.h):

@interface DDFileReader : NSObject {
    NSString * filePath;

    NSFileHandle * fileHandle;
    unsigned long long currentOffset;
    unsigned long long totalFileLength;

    NSString * lineDelimiter;
    NSUInteger chunkSize;

@property (nonatomic, copy) NSString * lineDelimiter;
@property (nonatomic) NSUInteger chunkSize;

- (id) initWithFilePath:(NSString *)aPath;

- (NSString *) readLine;
- (NSString *) readTrimmedLine;

- (void) enumerateLinesUsingBlock:(void(^)(NSString*, BOOL *))block;


Implementation (.m)

#import "DDFileReader.h"

@interface NSData (DDAdditions)

- (NSRange) rangeOfData_dd:(NSData *)dataToFind;


@implementation NSData (DDAdditions)

- (NSRange) rangeOfData_dd:(NSData *)dataToFind {

    const void * bytes = [self bytes];
    NSUInteger length = [self length];

    const void * searchBytes = [dataToFind bytes];
    NSUInteger searchLength = [dataToFind length];
    NSUInteger searchIndex = 0;

    NSRange foundRange = {NSNotFound, searchLength};
    for (NSUInteger index = 0; index < length; index++) {
        if (((char *)bytes)[index] == ((char *)searchBytes)[searchIndex]) {
            //the current character matches
            if (foundRange.location == NSNotFound) {
                foundRange.location = index;
            if (searchIndex >= searchLength) { return foundRange; }
        } else {
            searchIndex = 0;
            foundRange.location = NSNotFound;
    return foundRange;


@implementation DDFileReader
@synthesize lineDelimiter, chunkSize;

- (id) initWithFilePath:(NSString *)aPath {
    if (self = [super init]) {
        fileHandle = [NSFileHandle fileHandleForReadingAtPath:aPath];
        if (fileHandle == nil) {
            [self release]; return nil;

        lineDelimiter = [[NSString alloc] initWithString:@"\n"];
        [fileHandle retain];
        filePath = [aPath retain];
        currentOffset = 0ULL;
        chunkSize = 10;
        [fileHandle seekToEndOfFile];
        totalFileLength = [fileHandle offsetInFile];
        //we don't need to seek back, since readLine will do that.
    return self;

- (void) dealloc {
    [fileHandle closeFile];
    [fileHandle release], fileHandle = nil;
    [filePath release], filePath = nil;
    [lineDelimiter release], lineDelimiter = nil;
    currentOffset = 0ULL;
    [super dealloc];

- (NSString *) readLine {
    if (currentOffset >= totalFileLength) { return nil; }

    NSData * newLineData = [lineDelimiter dataUsingEncoding:NSUTF8StringEncoding];
    [fileHandle seekToFileOffset:currentOffset];
    NSMutableData * currentData = [[NSMutableData alloc] init];
    BOOL shouldReadMore = YES;

    NSAutoreleasePool * readPool = [[NSAutoreleasePool alloc] init];
    while (shouldReadMore) {
        if (currentOffset >= totalFileLength) { break; }
        NSData * chunk = [fileHandle readDataOfLength:chunkSize];
        NSRange newLineRange = [chunk rangeOfData_dd:newLineData];
        if (newLineRange.location != NSNotFound) {

            //include the length so we can include the delimiter in the string
            chunk = [chunk subdataWithRange:NSMakeRange(0, newLineRange.location+[newLineData length])];
            shouldReadMore = NO;
        [currentData appendData:chunk];
        currentOffset += [chunk length];
    [readPool release];

    NSString * line = [[NSString alloc] initWithData:currentData encoding:NSUTF8StringEncoding];
    [currentData release];
    return [line autorelease];

- (NSString *) readTrimmedLine {
    return [[self readLine] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

- (void) enumerateLinesUsingBlock:(void(^)(NSString*, BOOL*))block {
  NSString * line = nil;
  BOOL stop = NO;
  while (stop == NO && (line = [self readLine])) {
    block(line, &stop);


The class was done by Dave DeLong

Set cursor position on contentEditable <div>

I had a related situation, where I specifically needed to set the cursor position to the END of a contenteditable div. I didn't want to use a full fledged library like Rangy, and many solutions were far too heavyweight.

In the end, I came up with this simple jQuery function to set the carat position to the end of a contenteditable div:

$.fn.focusEnd = function() {
    var tmp = $('<span />').appendTo($(this)),
        node = tmp.get(0),
        range = null,
        sel = null;

    if (document.selection) {
        range = document.body.createTextRange();
    } else if (window.getSelection) {
        range = document.createRange();
        sel = window.getSelection();
    return this;

The theory is simple: append a span to the end of the editable, select it, and then remove the span - leaving us with a cursor at the end of the div. You could adapt this solution to insert the span wherever you want, thus putting the cursor at a specific spot.

Usage is simple:


That's it!

List comprehension with if statement

You got the order wrong. The if should be after the for (unless it is in an if-else ternary operator)

[y for y in a if y not in b]

This would work however:

[y if y not in b else other_value for y in a]

Best XML Parser for PHP

It depends on what you are trying to do with the XML files. If you are just trying to read the XML file (like a configuration file), The Wicked Flea is correct in suggesting SimpleXML since it creates what amounts to nested ArrayObjects. e.g. value will be accessible by $xml->root->child.

If you are looking to manipulate the XML files you're probably best off using DOM XML

Example JavaScript code to parse CSV data

I'm not sure why I couldn't get Kirtan's example to work for me. It seemed to be failing on empty fields or maybe fields with trailing commas...

This one seems to handle both.

I did not write the parser code, just a wrapper around the parser function to make this work for a file. See attribution.

    var Strings = {
         * Wrapped CSV line parser
         * @param s      String delimited CSV string
         * @param sep    Separator override
         * @attribution: (comments closed on blog :( )
        parseCSV : function(s,sep) {
            var universalNewline = /\r\n|\r|\n/g;
            var a = s.split(universalNewline);
            for(var i in a){
                for (var f = a[i].split(sep = sep || ","), x = f.length - 1, tl; x >= 0; x--) {
                    if (f[x].replace(/"\s+$/, '"').charAt(f[x].length - 1) == '"') {
                        if ((tl = f[x].replace(/^\s+"/, '"')).length > 1 && tl.charAt(0) == '"') {
                            f[x] = f[x].replace(/^\s*"|"\s*$/g, '').replace(/""/g, '"');
                          } else if (x) {
                        f.splice(x - 1, 2, [f[x - 1], f[x]].join(sep));
                      } else f = f.shift().split(sep).concat(f);
                    } else f[x].replace(/""/g, '"');
                  } a[i] = f;
        return a;

How can I upgrade NumPy?

The error you mentioned happens when you have two versions of NumPy on your system. As you mentioned, the version of NumPy you imported is still not upgraded since you tried to upgrade it through pip (it will upgrade the version existing in '/Library/Python/2.7/site-packages' ).

However Python still loads the packages from '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/numpy' where the pre-installed packages live.

In order to upgrade that version you have to use easy_install. The other way around this problem is using virtualenv and setting up a new environment with all the requirements you need.

Getting the parent of a directory in Bash

Started from the idea/comment Charles Duffy - Dec 17 '14 at 5:32 on the topic Get current directory name (without full path) in a Bash script

# comment : by Charles Duffy - Dec 17 '14 at 5:32
# at the beginning :

declare -a dirName[]

function getDirNames(){
dirNr="$(  IFS=/ read -r -a dirs <<<"${dirTree}"; printf '%s\n' "$((${#dirs[@]} - 1))"  )"

for(( cnt=0 ; cnt < ${dirNr} ; cnt++))
      dirName[$cnt]="$( IFS=/ read -r -a dirs <<<"$PWD"; printf '%s\n' "${dirs[${#dirs[@]} - $(( $cnt+1))]}"  )"
      #information – feedback
      echo "$cnt :  ${dirName[$cnt]}"


FPDF error: Some data has already been output, can't send PDF

For fpdf to work properly, there cannot be any output at all beside what fpdf generates. For example, this will work:

$pdf = new FPDF();
$pdf->Cell(40,10,'Hello World!');

While this will not (note the leading space before the opening <? tag)

$pdf = new FPDF();
$pdf->Cell(40,10,'Hello World!');

Also, this will not work either (the echo will break it):

echo "About to create pdf";
$pdf = new FPDF();
$pdf->Cell(40,10,'Hello World!');

I'm not sure about the drupal side of things, but I know that absolutely zero non-fpdf output is a requirement for fpdf to work.

add ob_start (); at the top and at the end add ob_end_flush();

    $pdf = new FPDF();
    $pdf->Cell(40,10,'Hello World!');

give me an error as below:
FPDF error: Some data has already been output, can't send PDF

to over come this error: go to fpdf.php in that,goto line number 996

function Output($name='', $dest='')

after that make changes like this:

function Output($name='', $dest='') {   
    ob_clean();     //Output PDF to so

Hi do you have a session header on the top of your page. or any includes If you have then try to add this codes on top pf your page it should works fine.


while (ob_get_level())
header("Content-Encoding: None", true);


cheers :-)

In my case i had set:

ini_set('display_errors', 'on');
error_reporting(E_ALL | E_STRICT);

When i made the request to generate the report, some warnings were displayed in the browser (like the usage of deprecated functions).
Turning off the display_errors option, the report was generated successfully.

How to get resources directory path programmatically



File folder = new ClassPathResource("sql").getFile();
File[] listOfFiles = folder.listFiles();

It is worth noting that this will limit your deployment options, ClassPathResource.getFile() only works if the container has exploded (unzipped) your war file.

Where is the WPF Numeric UpDown control?

Go to NugetPackage manager of you project-> Browse and search for mahApps.Metro -> install package into you project. You will see Reference added: MahApps.Metro. Then in you XAML code add:


Where you want to use your object add:

<mah:NumericUpDown x:Name="NumericUpDown" ... /> 

Enjoy the full extensibility of the object (Bindings, triggers and so on...).

How can I disable selected attribute from select2() dropdown Jquery?


This works for me.

Entity Framework code-first: migration fails with update-database, forces unneccessary(?) add-migration

Entity Framework does have some issues around identity fields.

You can't add GUID identity on existing table

Migrations: does not detect changes to DatabaseGeneratedOption

Reverse engineering does not mark GUID keys with default NEWSEQUENTIALID() as store generated identities

None of these describes your issue exactly and the Down() method in your extra migration is interesting because it appears to be attempting to remove IDENTITY from the column when your CREATE TABLE in the initial migration appears to set it!

Furthermore, if you use Update-Database -Script or Update-Database -Verbose to view the sql that is run from these AlterColumn methods you will see that the sql is identical in Up and Down, and actually does nothing. IDENTITY remains unchanged (for the current version - EF 6.0.2 and below) - as described in the first 2 issues I linked to.

I think you should delete the redundant code in your extra migration and live with an empty migration for now. And you could subscribe to/vote for the issues to be addressed.


Change IDENTITY option does diddly squat

Switch Identity On/Off With A Custom Migration Operation

Sass and combined child selector

For that single rule you have, there isn't any shorter way to do it. The child combinator is the same in CSS and in Sass/SCSS and there's no alternative to it.

However, if you had multiple rules like this:

#foo > ul > li > ul > li > a:nth-child(3n+1) {
    color: red;

#foo > ul > li > ul > li > a:nth-child(3n+2) {
    color: green;

#foo > ul > li > ul > li > a:nth-child(3n+3) {
    color: blue;

You could condense them to one of the following:

/* Sass */
#foo > ul > li > ul > li
    > a:nth-child(3n+1)
        color: red
    > a:nth-child(3n+2)
        color: green
    > a:nth-child(3n+3)
        color: blue

/* SCSS */
#foo > ul > li > ul > li {
    > a:nth-child(3n+1) { color: red; }
    > a:nth-child(3n+2) { color: green; }
    > a:nth-child(3n+3) { color: blue; }

Update multiple columns in SQL

I did this in MySql and it updated multiple columns in a single record, so try this if you are using MySql as your server:

"UPDATE creditor_tb SET credit_amount='" & CDbl(cur_amount) & "'
                   , totalamount_to_pay='" & current_total & "',   
        WHERE credit_id='" & lbcreditId.Text & "'". 

However, I was coding in using MySql server, but you can take it to your favorite programming language as far as you are using MySql as your server.


Try this after curl_exec to see what's the problem:

print curl_error($ch);

If it's print something like 'malformed' then check your URL format.

How do I check if a PowerShell module is installed?

Coming from Linux background. I would prefer using something similar to grep, therefore I use Select-String. So even if someone is not sure of the complete module name. They can provide the initials and determine whether the module exists or not.

Get-Module -ListAvailable -All | Select-String Module_Name(can be a part of the module name)

setState(...): Can only update a mounted or mounting component. This usually means you called setState() on an unmounted component. This is a no-op

A lot of the answers in this thread get the point of using refs, but I think a complete example would be good. Since you're operating on an actual DOM node by using the event listener and stepping out of the React context, a ref should be considered the standard solution. Here's a complete example:

class someComponent extends Component {
  constructor(props) {
    this.node = null
  render() {
    return (
      <div ref={node => { this.node = node }}>Content</div>
  handleEvent(event) {
    if (this.node) {
  componentDidMount() {
    //as soon as render completes, the node will be registered.
    const handleEvent = this.handleEvent.bind(this)
    this.node.addEventListener('click', handleEvent)
  componentWillUnmount() {
    const handleEvent = this.handleEvent.bind(this)
    this.node.removeEventListener('click', handleEvent)

Overriding css style?

You just have to reset the values you don't want to their defaults. No need to get into a mess by using !important.

#zoomTarget .slikezamenjanje img {
    max-height: auto;
    padding-right: 0px;


I think the key datum you are missing is that CSS comes with default values. If you want to override a value, set it back to its default, which you can look up.

For example, all CSS height and width attributes default to auto.

Alter a SQL server function to accept new optional parameter


When a parameter of the function has a default value, the keyword DEFAULT must be specified when the function is called to retrieve the default value. This behavior is different from using parameters with default values in stored procedures in which omitting the parameter also implies the default value.

So you need to do:

SELECT dbo.fCalculateEstimateDate(647,DEFAULT)

Call a REST API in PHP

as @Christoph Winkler mentioned this is a base class for achieving it:


// This class has all the necessary code for making API calls thru curl library

class CurlHelper {

// This method will perform an action/method thru HTTP/API calls
// Parameter description:
// Method= POST, PUT, GET etc
// Data= array("param" => "value") ==> index.php?param=value
public static function perform_http_request($method, $url, $data = false)
    $curl = curl_init();

    switch ($method)
        case "POST":
            curl_setopt($curl, CURLOPT_POST, 1);

            if ($data)
                curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
        case "PUT":
            curl_setopt($curl, CURLOPT_PUT, 1);
            if ($data)
                $url = sprintf("%s?%s", $url, http_build_query($data));

    // Optional Authentication:
    //curl_setopt($curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
    //curl_setopt($curl, CURLOPT_USERPWD, "username:password");

    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);

    $result = curl_exec($curl);


    return $result;


Then you can always include the file and use it e.g.: any.php

    $action = "GET";
    $url = ""
    echo "Trying to reach ...";
    echo $url;
    $parameters = array("param" => "value");
    $result = CurlHelper::perform_http_request($action, $url, $parameters);
    echo print_r($result)

How to pass boolean values to a PowerShell script from a command prompt

This is an older question, but there is actually an answer to this in the PowerShell documentation. I had the same problem, and for once RTFM actually solved it. Almost.

Documentation for the -File parameter states that "In rare cases, you might need to provide a Boolean value for a switch parameter. To provide a Boolean value for a switch parameter in the value of the File parameter, enclose the parameter name and value in curly braces, such as the following: -File .\Get-Script.ps1 {-All:$False}"

I had to write it like this:

PowerShell.Exe -File MyFile.ps1 {-SomeBoolParameter:False}

So no '$' before the true/false statement, and that worked for me, on PowerShell 4.0

How to log request and response body with Retrofit-Android?

If you are using Retrofit2 and okhttp3 then you need to know that Interceptor works by queue. So add loggingInterceptor at the end, after your other Interceptors:

HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
        if (BuildConfig.DEBUG)

 new OkHttpClient.Builder()
                .connectTimeout(60, TimeUnit.SECONDS)
                .readTimeout(60, TimeUnit.SECONDS)
                .writeTimeout(60, TimeUnit.SECONDS)
                .addInterceptor(new CatalogInterceptor(context))
                .addInterceptor(new OAuthInterceptor(context))
                .authenticator(new BearerTokenAuthenticator(context))
                .addInterceptor(loggingInterceptor)//at the end

IllegalArgumentException or NullPointerException for a null parameter?

It seems like an IllegalArgumentException is called for if you don't want null to be an allowed value, and the NullPointerException would be thrown if you were trying to use a variable that turns out to be null.

How do I dynamically set the selected option of a drop-down list using jQuery, JavaScript and HTML?

Here is another way you can change the selected option of a <select> element in javascript. You can use


Setting it to 1 will make the second element of the dropdown selected. The select element index start from 0.

Here is a sample code. Check if you can use this type of approach:

<script language="javascript">

function changeSelected() { 


<form name="f1">

<select id="salesperson" > 
   <option value"">james</option>
   <option value"">john</option>  
<input type="button" value="Change Selected" onClick="changeSelected();">


Getting multiple keys of specified value of a generic Dictionary?

Dictionaries aren't really meant to work like this, because while uniqueness of keys is guaranteed, uniqueness of values isn't. So e.g. if you had

var greek = new Dictionary<int, string> { { 1, "Alpha" }, { 2, "Alpha" } };

What would you expect to get for greek.WhatDoIPutHere("Alpha")?

Therefore you can't expect something like this to be rolled into the framework. You'd need your own method for your own unique uses---do you want to return an array (or IEnumerable<T>)? Do you want to throw an exception if there are multiple keys with the given value? What about if there are none?

Personally I'd go for an enumerable, like so:

IEnumerable<TKey> KeysFromValue<TKey, TValue>(this Dictionary<TKey, TValue> dict, TValue val)
    if (dict == null)
        throw new ArgumentNullException("dict");
    return dict.Keys.Where(k => dict[k] == val);

var keys = greek.KeysFromValue("Beta");
int exceptionIfNotExactlyOne = greek.KeysFromValue("Beta").Single();

Upload files with HTTPWebrequest (multipart/form-data)

I was looking to do file upload and add some parameters to a multipart/form-data request in VB.NET and not through a regular forms post. Thanks to @JoshCodes answer I got the direction I was looking for. I am posting my solution to help others find a way to perform a post with both file and parameters the html equivalent of what I try to achieve is : html

<form action="your-api-endpoint" enctype="multipart/form-data" method="post"> 
<input type="hidden" name="action" value="api-method-name"/> 
<input type="hidden" name="apiKey" value="gs1xxxxxxxxxxxxxex"/> 
<input type="hidden" name="access" value="protected"/> 
<input type="hidden" name="name" value="test"/> 
<input type="hidden" name="title" value="test"/> 
<input type="hidden" name="signature" value="cf1d4xxxxxxxxcd5"/> 
<input type="file" name="file"/> 
<input type="submit" name="_upload" value="Upload"/> 

Due to the fact that I have to provide the apiKey and the signature (which is a calculated checksum of the request parameters and api key concatenated string), I needed to do it server side. The other reason I needed to do it server side is the fact that the post of the file can be performed at any time by pointing to a file already on the server (providing the path), so there would be no manually selected file during form post thus form data file would not contain the file stream.Otherwise I could have calculated the checksum via an ajax callback and submitted the file through the html post using JQuery. I am using .net version 4.0 and cannot upgrade to 4.5 in the actual solution. So I had to install the Microsoft.Net.Http using nuget cmd

PM> install-package Microsoft.Net.Http

Private Function UploadFile(req As ApiRequest, filePath As String, fileName As String) As String
    Dim result = String.empty
        ''//Get file stream
        Dim paramFileStream As Stream = File.OpenRead(filePath)
        Dim fileStreamContent As HttpContent = New  StreamContent(paramFileStream)
        Using client = New HttpClient()
            Using formData = New MultipartFormDataContent()
                ''// This adds parameter name ("action")
                ''// parameter value (req.Action) to form data
                formData.Add(New StringContent(req.Action), "action")
                formData.Add(New StringContent(req.ApiKey), "apiKey")
                For Each param In req.Parameters
                    formData.Add(New StringContent(param.Value), param.Key)
                formData.Add(New StringContent(req.getRequestSignature.Qualifier), "signature")
                ''//This adds the file stream and file info to form data
                formData.Add(fileStreamContent, "file", fileName)
                ''//We are now sending the request
                Dim response = client.PostAsync(GetAPIEndpoint(), formData).Result
                ''//We are here reading the response
                Dim readR = New StreamReader(response.Content.ReadAsStreamAsync().Result, Encoding.UTF8)
                Dim respContent = readR.ReadToEnd()

                If Not response.IsSuccessStatusCode Then
                    result =  "Request Failed : Code = " & response.StatusCode & "Reason = " & response.ReasonPhrase & "Message = " & respContent
                End If
                result.Value = respContent
            End Using
        End Using
    Catch ex As Exception
        result = "An error occurred : " & ex.Message
    End Try

    Return result
End Function

How to access PHP session variables from jQuery function in a .js file?

I was struggling with the same problem and stumbled upon this page. Another solution I came up with would be this :

In your html, echo the session variable (mine here is $_SESSION['origin']) to any element of your choosing : <p id="sessionOrigin"><?=$_SESSION['origin'];?></p>

In your js, using jQuery you can access it like so : $("#sessionOrigin").text();

EDIT: or even better, put it in a hidden input

<input type="hidden" name="theOrigin" value="<?=$_SESSION['origin'];?>"></input>

Uncaught (in promise) TypeError: Failed to fetch and Cors error

See's write-up on how CORS works.

You'll need your server to send back the proper response headers, something like:

Access-Control-Allow-Origin: http://foo.example
Access-Control-Allow-Methods: POST, PUT, GET, OPTIONS
Access-Control-Allow-Headers: Origin, X-Requested-With, Content-Type, Accept, Authorization

Bear in mind you can use "*" for Access-Control-Allow-Origin that will only work if you're trying to pass Authentication data. In that case, you need to explicitly list the origin domains you want to allow. To allow multiple domains, see this post

How to obtain Certificate Signing Request

Since you installed a new OS you probably don't have any more of your private and public keys that you used to sign your app in to XCode before. You need to regenerate those keys on your machine by revoking your previous certificate and asking for a new one on the iOS development portal. As part of the process you will be asked to generate a Certificate Signing Request which is where you seem to have a problem.

You will find all you need there which consists of (from the official doc):

1.Open Keychain Access on your Mac (located in Applications/Utilities).

2.Open Preferences and click Certificates. Make sure both Online Certificate Status Protocol and Certificate Revocation List are set to Off.

3.Choose Keychain Access > Certificate Assistant > Request a Certificate From a Certificate Authority.

Note: If you have a private key selected when you do this, the CSR won’t be accepted. Make sure no private key is selected. Enter your user email address and common name. Use the same address and name as you used to register in the iOS Developer Program. No CA Email Address is required.

4.Select the options “Saved to disk” and “Let me specify key pair information” and click Continue.

5.Specify a filename and click Save. (make sure to replace .certSigningRequest with .csr)

For the Key Size choose 2048 bits and for Algorithm choose RSA. Click Continue and the Certificate Assistant creates a CSR and saves the file to your specified location.

Using global variables between files?

The problem is you defined myList from, but needs to use it. Here is a clean way to solve this problem: move all globals to a file, I call this file This file is responsible for defining globals and initializing them:


def init():
    global myList
    myList = []

Next, your subfile can import globals:


import settings

def stuff():

Note that subfile does not call init()— that task belongs to


import settings
import subfile

settings.init()          # Call only once
subfile.stuff()         # Do stuff with global var
print settings.myList[0] # Check the result

This way, you achieve your objective while avoid initializing global variables more than once.

How to call VS Code Editor from terminal / command line

In windows you can add following path to environment variable

C:\Users\username\AppData\Local\Programs\Microsoft VS Code\bin

Is it possible to run CUDA on AMD GPUs?

I think it is going to be possible soon in AMD FirePro GPU's, see press release here but support is coming 2016 Q1 for the developing tools:

An early access program for the "Boltzmann Initiative" tools is planned for Q1 2016.

How to run or debug php on Visual Studio Code (VSCode)

To debug php with vscode,you need these things:

  1. vscode with php debuge plugin(XDebug) installed;
  2. php with downloaded and configured;
  3. a web server,such as apache/nginx or just nothing(use the php built-in server)

you can gently walk through step 1 and 2,by following the vscode official guide.It is fully recommended to use XDebug installation wizard to verify your XDebug configuration.

If you want to debug without a standalone web server,the php built-in maybe a choice.Start the built-in server by php -S localhost:port -t path/to/your/project command,setting your project dir as document root.You can refer to this post for more details.

Useful example of a shutdown hook in Java?

Shutdown Hooks are unstarted threads that are registered with Runtime.addShutdownHook().JVM does not give any guarantee on the order in which shutdown hooks are started.For more info refer

What encoding/code page is cmd.exe using?



to see your current code page (as Dewfy already said).



to see all installed code pages and find out what your code page number means.

You need to have Windows Server 2003 Resource kit installed (works on Windows XP) to use nlsinfo.

Is it possible to serialize and deserialize a class in C++?

The Boost::serialization library handles this rather elegantly. I've used it in several projects. There's an example program, showing how to use it, here.

The only native way to do it is to use streams. That's essentially all the Boost::serialization library does, it extends the stream method by setting up a framework to write objects to a text-like format and read them from the same format.

For built-in types, or your own types with operator<< and operator>> properly defined, that's fairly simple; see the C++ FAQ for more information.

CORS Access-Control-Allow-Headers wildcard being ignored?

Support for wildcards in the Access-Control-Allow-Headers header was added to the living standard only in May 2016, so it may not be supported by all browsers. On browser which don't implement this yet, it must be an exact match:

If you expect a large number of headers, you can read in the value of the Access-Control-Request-Headers header and echo that value back in the Access-Control-Allow-Headers header.

How to trigger SIGUSR1 and SIGUSR2?

They are user-defined signals, so they aren't triggered by any particular action. You can explicitly send them programmatically:

#include <signal.h>

kill(pid, SIGUSR1);

where pid is the process id of the receiving process. At the receiving end, you can register a signal handler for them:

#include <signal.h>

void my_handler(int signum)
    if (signum == SIGUSR1)
        printf("Received SIGUSR1!\n");

signal(SIGUSR1, my_handler);

How to find sum of several integers input by user using do/while, While statement or For statement

The FOR loop worked well, I modified it a tiny bit:

using namespace std;
int main ()

    int sum = 0;
    int number;
    int numberitems;

    cout << "Enter number of items: \n";
    cin >> numberitems;

    for(int i=0;i<numberitems;i++)
        cout << "Enter number: \n";
        cin >> number; 


    cout<<"sum is: "<< sum<<endl;

HOWEVER, the WHILE loop has got some errors on line 11 (Count was not declared in this scope). What could be the issue? Also, if you would have a solution using DO,WHILE loop it would be wonderful. Thanks

Giving graphs a subtitle in matplotlib

Just use TeX ! This works :

title(r"""\Huge{Big title !} \newline \tiny{Small subtitle !}""")

EDIT: To enable TeX processing, you need to add the "usetex = True" line to matplotlib parameters:

fig_size = [12.,7.5]
params = {'axes.labelsize': 8,
      'text.fontsize':   6,
      'legend.fontsize': 7,
      'xtick.labelsize': 6,
      'ytick.labelsize': 6,
      'text.usetex': True,       # <-- There 
      'figure.figsize': fig_size,

I guess you also need a working TeX distribution on your computer. All details are given at this page:

Beamer: How to show images as step-by-step images

You can simply specify a series of images like this:


This will produce three slides with the images A to C in exactly the same position.

Read/Write String from/to a File in Android


class FileReadWriteService {

    private var context:Context? = ContextHolder.instance.appContext

    fun writeFileOnInternalStorage(fileKey: String, sBody: String) {
        val file = File(context?.filesDir, "files")
        try {
            if (!file.exists()) {
            val fileToWrite = File(file, fileKey)
            val writer = FileWriter(fileToWrite)
        } catch (e: Exception) {
            Logger.e(classTag, e)

    fun readFileOnInternalStorage(fileKey: String): String {
        val file = File(context?.filesDir, "files")
        var ret = ""
        try {
            if (!file.exists()) {
                return ret
            val fileToRead = File(file, fileKey)
            val reader = FileReader(fileToRead)
            ret = reader.readText()
        } catch (e: Exception) {
            Logger.e(classTag, e)
        return ret

How to make a DIV not wrap?

None of the above worked for me.

In my case, I needed to add the following to the user control I had created:


Plotting time-series with Date labels on x-axis

I like using the ggplot2 for this sort of thing:

df$Date <- as.Date( df$Date, '%m/%d/%Y')
ggplot( data = df, aes( Date, Visits )) + geom_line() 

enter image description here

Set title background color

I have done this by changing style color values in "res" -> "values" -> "colors.xml" enter image description here

This will change colors for entire project which is fine with me.

enter image description here

Arduino Nano - "avrdude: ser_open():system can't open device "\\.\COM1": the system cannot find the file specified"

I was having this same issue this morning. When I checked my Device Manager, it showed COM4 properly, and when I checked in the Arduino IDE COM4 just wasn't an option. Only COM1 was listed.
I tried unplugging and plugging my Arduino in and out a couple more times and eventually COM4 showed up again in the IDE. I didn't have to change any settings.
Hopefully that helps somebody.

jQuery - Redirect with post data

Construct and fill out a hidden method=POST action="" form and submit it, rather than using window.location at all.


   '<form action="url" name="form" method="post" style="display:none;">
    <input type="text" name="name" value="' + value + '" /></form>');

Git reset single file in feature branch to be the same as in master

you are almost there; you just need to give the reference to master; since you want to get the file from the master branch:

git checkout master -- filename

Note that the differences will be cached; so if you want to see the differences you obtained; use

git diff --cached

How to detect scroll position of page using jQuery

You are looking for the window.scrollTop() function.

$(window).scroll(function() {
    var height = $(window).scrollTop();

    if(height  > some_number) {
        // do something

Python: printing a file to stdout

My shortened version in Python3


SVN repository backup strategies

For the daily and full backup solution just use the SVN backup scripts here.

What does "javax.naming.NoInitialContextException" mean?

It means that there is no initial context :)

But seriously folks, JNDI (javax.naming) is all about looking up objects or resources from some directory or provider. To look something up, you need somewhere to look (this is the InitialContext). NoInitialContextException means "I want to find the telephone number for John Smith, but I have no phonebook to look in".

An InitialContext can be created in any number of ways. It can be done manually, for instance creating a connection to an LDAP server. It can also be set up by an application server inside which you run your application. In this case, the container (application server) already provides you with a "phonebook", through which you can look up anything the application server makes available. This is often configurable and a common way of moving this type of configuration from the application implementation to the container, where it can be shared across all applications in the server.

UPDATE: from the code snippet you post it looks like you are trying to run code stand-alone that is meant to be run in an application server. In this case, the code attempting to get a connection to a database from the "phonebook". This is one of the resources that is often configured in the application server container. So, rather than having to manage configuration and connections to the database in your code, you can configure it in your application server and simple ask for a connection (using JNDI) in your code.

Ajax LARAVEL 419 POST error

Laravel 419 post error is usually related with api.php and token authorization

Laravel automatically generates a CSRF "token" for each active user session managed by the application. This token is used to verify that the authenticated user is the one actually making the requests to the application.

Add this to your ajax call

    headers: {
        'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')

or you can exclude some URIs in VerifyCSRF token middleware

 protected $except = [

How to make a phone call programmatically?

Here I will show you that how you can make a phone call from your activity. To make a call you have to put down this code in your app.

try {
    Intent my_callIntent = new Intent(Intent.ACTION_CALL);
    //here the word 'tel' is important for making a call...
} catch (ActivityNotFoundException e) {
    Toast.makeText(getApplicationContext(), "Error in your phone call"+e.getMessage(), Toast.LENGTH_LONG).show();

What is System, out, println in System.out.println() in Java

The first answer you posted (System is a built-in class...) is pretty spot on.

You can add that the System class contains large portions which are native and that is set up by the JVM during startup, like connecting the System.out printstream to the native output stream associated with the "standard out" (console).

How to find a user's home directory on linux or unix?

For UNIX-Like systems you might want to execute "echo ~username" using the shell (so use Runtime.exec() to run {"/bin/sh", "-c", "echo ~username"}).

pandas loc vs. iloc vs. at vs. iat?

There are two primary ways that pandas makes selections from a DataFrame.

  • By Label
  • By Integer Location

The documentation uses the term position for referring to integer location. I do not like this terminology as I feel it is confusing. Integer location is more descriptive and is exactly what .iloc stands for. The key word here is INTEGER - you must use integers when selecting by integer location.

Before showing the summary let's all make sure that ...

.ix is deprecated and ambiguous and should never be used

There are three primary indexers for pandas. We have the indexing operator itself (the brackets []), .loc, and .iloc. Let's summarize them:

  • [] - Primarily selects subsets of columns, but can select rows as well. Cannot simultaneously select rows and columns.
  • .loc - selects subsets of rows and columns by label only
  • .iloc - selects subsets of rows and columns by integer location only

I almost never use .at or .iat as they add no additional functionality and with just a small performance increase. I would discourage their use unless you have a very time-sensitive application. Regardless, we have their summary:

  • .at selects a single scalar value in the DataFrame by label only
  • .iat selects a single scalar value in the DataFrame by integer location only

In addition to selection by label and integer location, boolean selection also known as boolean indexing exists.

Examples explaining .loc, .iloc, boolean selection and .at and .iat are shown below

We will first focus on the differences between .loc and .iloc. Before we talk about the differences, it is important to understand that DataFrames have labels that help identify each column and each row. Let's take a look at a sample DataFrame:

df = pd.DataFrame({'age':[30, 2, 12, 4, 32, 33, 69],
                   'color':['blue', 'green', 'red', 'white', 'gray', 'black', 'red'],
                   'food':['Steak', 'Lamb', 'Mango', 'Apple', 'Cheese', 'Melon', 'Beans'],
                   'height':[165, 70, 120, 80, 180, 172, 150],
                   'score':[4.6, 8.3, 9.0, 3.3, 1.8, 9.5, 2.2],
                   'state':['NY', 'TX', 'FL', 'AL', 'AK', 'TX', 'TX']
                  index=['Jane', 'Nick', 'Aaron', 'Penelope', 'Dean', 'Christina', 'Cornelia'])

enter image description here

All the words in bold are the labels. The labels, age, color, food, height, score and state are used for the columns. The other labels, Jane, Nick, Aaron, Penelope, Dean, Christina, Cornelia are used as labels for the rows. Collectively, these row labels are known as the index.

The primary ways to select particular rows in a DataFrame are with the .loc and .iloc indexers. Each of these indexers can also be used to simultaneously select columns but it is easier to just focus on rows for now. Also, each of the indexers use a set of brackets that immediately follow their name to make their selections.

.loc selects data only by labels

We will first talk about the .loc indexer which only selects data by the index or column labels. In our sample DataFrame, we have provided meaningful names as values for the index. Many DataFrames will not have any meaningful names and will instead, default to just the integers from 0 to n-1, where n is the length(number of rows) of the DataFrame.

There are many different inputs you can use for .loc three out of them are

  • A string
  • A list of strings
  • Slice notation using strings as the start and stop values

Selecting a single row with .loc with a string

To select a single row of data, place the index label inside of the brackets following .loc.


This returns the row of data as a Series

age           4
color     white
food      Apple
height       80
score       3.3
state        AL
Name: Penelope, dtype: object

Selecting multiple rows with .loc with a list of strings

df.loc[['Cornelia', 'Jane', 'Dean']]

This returns a DataFrame with the rows in the order specified in the list:

enter image description here

Selecting multiple rows with .loc with slice notation

Slice notation is defined by a start, stop and step values. When slicing by label, pandas includes the stop value in the return. The following slices from Aaron to Dean, inclusive. Its step size is not explicitly defined but defaulted to 1.


enter image description here

Complex slices can be taken in the same manner as Python lists.

.iloc selects data only by integer location

Let's now turn to .iloc. Every row and column of data in a DataFrame has an integer location that defines it. This is in addition to the label that is visually displayed in the output. The integer location is simply the number of rows/columns from the top/left beginning at 0.

There are many different inputs you can use for .iloc three out of them are

  • An integer
  • A list of integers
  • Slice notation using integers as the start and stop values

Selecting a single row with .iloc with an integer


This returns the 5th row (integer location 4) as a Series

age           32
color       gray
food      Cheese
height       180
score        1.8
state         AK
Name: Dean, dtype: object

Selecting multiple rows with .iloc with a list of integers

df.iloc[[2, -2]]

This returns a DataFrame of the third and second to last rows:

enter image description here

Selecting multiple rows with .iloc with slice notation


enter image description here

Simultaneous selection of rows and columns with .loc and .iloc

One excellent ability of both .loc/.iloc is their ability to select both rows and columns simultaneously. In the examples above, all the columns were returned from each selection. We can choose columns with the same types of inputs as we do for rows. We simply need to separate the row and column selection with a comma.

For example, we can select rows Jane, and Dean with just the columns height, score and state like this:

df.loc[['Jane', 'Dean'], 'height':]

enter image description here

This uses a list of labels for the rows and slice notation for the columns

We can naturally do similar operations with .iloc using only integers.

df.iloc[[1,4], 2]
Nick      Lamb
Dean    Cheese
Name: food, dtype: object

Simultaneous selection with labels and integer location

.ix was used to make selections simultaneously with labels and integer location which was useful but confusing and ambiguous at times and thankfully it has been deprecated. In the event that you need to make a selection with a mix of labels and integer locations, you will have to make both your selections labels or integer locations.

For instance, if we want to select rows Nick and Cornelia along with columns 2 and 4, we could use .loc by converting the integers to labels with the following:

col_names = df.columns[[2, 4]]
df.loc[['Nick', 'Cornelia'], col_names] 

Or alternatively, convert the index labels to integers with the get_loc index method.

labels = ['Nick', 'Cornelia']
index_ints = [df.index.get_loc(label) for label in labels]
df.iloc[index_ints, [2, 4]]

Boolean Selection

The .loc indexer can also do boolean selection. For instance, if we are interested in finding all the rows where age is above 30 and return just the food and score columns we can do the following:

df.loc[df['age'] > 30, ['food', 'score']] 

You can replicate this with .iloc but you cannot pass it a boolean series. You must convert the boolean Series into a numpy array like this:

df.iloc[(df['age'] > 30).values, [2, 4]] 

Selecting all rows

It is possible to use .loc/.iloc for just column selection. You can select all the rows by using a colon like this:

df.loc[:, 'color':'score':2]

enter image description here

The indexing operator, [], can slice can select rows and columns too but not simultaneously.

Most people are familiar with the primary purpose of the DataFrame indexing operator, which is to select columns. A string selects a single column as a Series and a list of strings selects multiple columns as a DataFrame.


Jane          Steak
Nick           Lamb
Aaron         Mango
Penelope      Apple
Dean         Cheese
Christina     Melon
Cornelia      Beans
Name: food, dtype: object

Using a list selects multiple columns

df[['food', 'score']]

enter image description here

What people are less familiar with, is that, when slice notation is used, then selection happens by row labels or by integer location. This is very confusing and something that I almost never use but it does work.

df['Penelope':'Christina'] # slice rows by label

enter image description here

df[2:6:2] # slice rows by integer location

enter image description here

The explicitness of .loc/.iloc for selecting rows is highly preferred. The indexing operator alone is unable to select rows and columns simultaneously.

df[3:5, 'color']
TypeError: unhashable type: 'slice'

Selection by .at and .iat

Selection with .at is nearly identical to .loc but it only selects a single 'cell' in your DataFrame. We usually refer to this cell as a scalar value. To use .at, pass it both a row and column label separated by a comma.['Christina', 'color']

Selection with .iat is nearly identical to .iloc but it only selects a single scalar value. You must pass it an integer for both the row and column locations

df.iat[2, 5]

jQuery checkbox check/uncheck

Use .prop() instead and if we go with your code then compare like this:

Look at the example jsbin:

  $("#news_list tr").click(function () {
    var ele = $(this).find(':checkbox');
    if ($(':checked').length) {
      ele.prop('checked', false);
    } else {
      ele.prop('checked', true);


  1. Changed input to :checkbox.
  2. Comparing the length of the checked checkboxes.

Facebook API "This app is in development mode"

for testing purposes only you could Go to your facebook developer dashboard. create your app then in the top left corner open the apps dropdown menu and click create test app take the app ID and use instead.


How to print binary tree diagram?

Adapted from Vasya Novikov's answer to make it more binary, and use a StringBuilder for efficiency (concatenating String objects together in Java is generally inefficient).

public StringBuilder toString(StringBuilder prefix, boolean isTail, StringBuilder sb) {
    if(right!=null) {
        right.toString(new StringBuilder().append(prefix).append(isTail ? "¦   " : "    "), false, sb);
    sb.append(prefix).append(isTail ? "+-- " : "+-- ").append(value.toString()).append("\n");
    if(left!=null) {
        left.toString(new StringBuilder().append(prefix).append(isTail ? "    " : "¦   "), true, sb);
    return sb;

public String toString() {
    return this.toString(new StringBuilder(), true, new StringBuilder()).toString();


¦       +-- 7
¦   +-- 6
¦   ¦   +-- 5
+-- 4
    ¦   +-- 3
    +-- 2
        +-- 1
            +-- 0

Easiest way to convert int to string in C++

First include:

#include <string>
#include <sstream>

Second add the method:

template <typename T>
string NumberToString(T pNumber)
 ostringstream oOStrStream;
 oOStrStream << pNumber;
 return oOStrStream.str();

Use the method like this:



int x = 69;
string vStr = NumberToString(x) + " Hello word!."

DISABLE the Horizontal Scroll

You can try this all of method in our html page..

1st way

body { overflow-x:hidden; }

2nd way You can use the following in your CSS body tag:

overflow-y: scroll; overflow-x: hidden;

That will remove your scrollbar.

3rd way

body { min-width: 1167px; }

5th way

html, body { max-width: 100%; overflow-x: hidden; }

6th way

element { max-width: 100vw; overflow-x: hidden; }

4th way..

var docWidth = document.documentElement.offsetWidth; [] document.querySelectorAll('*'), function(el) { if (el.offsetWidth > docWidth) { console.log(el); } } );

Now i m searching about more..!!!!

escaping question mark in regex javascript

You can delimit your regexp with slashes instead of quotes and then a single backslash to escape the question mark. Try this:

var gent = /I like your Apartment. Could we schedule a viewing\?/g;

vagrant login as root by default

Add the following to your Vagrantfile:

config.ssh.username = 'root'
config.ssh.password = 'vagrant'
config.ssh.insert_key = 'true'

When you vagrant ssh henceforth, you will login as root and should expect the following:

==> mybox: Waiting for machine to boot. This may take a few minutes...
    mybox: SSH address:
    mybox: SSH username: root
    mybox: SSH auth method: password
    mybox: Warning: Connection timeout. Retrying...
    mybox: Warning: Remote connection disconnect. Retrying...
==> mybox: Inserting Vagrant public key within guest...
==> mybox: Key inserted! Disconnecting and reconnecting using new SSH key...
==> mybox: Machine booted and ready!

Update 23-Jun-2015: This works for version 1.7.2 as well. Keying security has improved since 1.7.0; this technique overrides back to the previous method which uses a known private key. This solution is not intended to be used for a box that is accessible publicly without proper security measures done prior to publishing.


Convert InputStream to byte array in Java

You can try Cactoos:

byte[] array = new BytesOf(stream).bytes();

How to grant remote access permissions to mysql server for user?

By mysql 8 and later version, you cannot add a user by granting privileges. it means with this query:

    IDENTIFIED BY 'type-root-password-here' 

mysql will return this error:

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 'IDENTIFIED BY 'written password' at line 1

this means you don't have a root user for % domain. so you need to first insert the user and then grant privileges like this:

mysql> CREATE USER 'root'@'%' IDENTIFIED BY 'your password';
Query OK, 0 rows affected (0.11 sec)

mysql> GRANT ALL ON *.* TO 'root'@'%';
Query OK, 0 rows affected (0.15 sec)


Dont forget to replace passwords with your specific passwords.

Server cannot set status after HTTP headers have been sent IIS7.5

You are actually trying to redirect a page which has some response to throw. So first you keep the information you have throw in a buffer using response.buffer = true in beginning of the page and then flush it when required using response.flush this error will get fixed

Remove non-ascii character in string

ASCII is in range of 0 to 127, so:

str.replace(/[^\x00-\x7F]/g, "");

Using an HTTP PROXY - Python

You can do it even without the HTTP_PROXY environment variable. Try this sample:

import urllib2

proxy_support = urllib2.ProxyHandler({"http":""})
opener = urllib2.build_opener(proxy_support)

html = urllib2.urlopen("").read()
print html

In your case it really seems that the proxy server is refusing the connection.

Something more to try:

import urllib2

#proxy = ""

proxies = {"http":"http://%s" % proxy}
url = ""
headers={'User-agent' : 'Mozilla/5.0'}

proxy_support = urllib2.ProxyHandler(proxies)
opener = urllib2.build_opener(proxy_support, urllib2.HTTPHandler(debuglevel=1))

req = urllib2.Request(url, None, headers)
html = urllib2.urlopen(req).read()
print html

Edit 2014: This seems to be a popular question / answer. However today I would use third party requests module instead.

For one request just do:

import requests

r = requests.get("", 
                 proxies={"http": ""})

For multiple requests use Session object so you do not have to add proxies parameter in all your requests:

import requests

s = requests.Session()
s.proxies = {"http": ""}

r = s.get("")

What is an Android PendingIntent?



Intents are typically used for starting Services. For example:

Intent intent = new Intent(CurrentClass.this, ServiceClass.class);

This is like when you call for a taxi:

Myself = CurrentClass
Taxi Driver = ServiceClass

Pending Intent

You will need to use something like this:

Intent intent = new Intent(CurrentClass.this, ServiceClass.class);
PendingIntent pi = PendingIntent.getService(parameter, parameter, intent, parameter);
getDataFromThirdParty(parameter, parameter, pi, parameter);

Now this Third party will start the service acting on your behalf. A real life analogy is Uber or Lyft who are both taxi companies.

You send a request for a ride to Uber/Lyft. They will then go ahead and call one of their drivers on your behalf.


Uber/Lyft ------ ThirdParty which receives PendingIntent
Myself --------- Class calling PendingIntent
Taxi Driver ---- ServiceClass

General guidelines to avoid memory leaks in C++


  • Forget Garbage Collection (Use RAII instead). Note that even the Garbage Collector can leak, too (if you forget to "null" some references in Java/C#), and that Garbage Collector won't help you to dispose of resources (if you have an object which acquired a handle to a file, the file won't be freed automatically when the object will go out of scope if you don't do it manually in Java, or use the "dispose" pattern in C#).
  • Forget the "one return per function" rule. This is a good C advice to avoid leaks, but it is outdated in C++ because of its use of exceptions (use RAII instead).
  • And while the "Sandwich Pattern" is a good C advice, it is outdated in C++ because of its use of exceptions (use RAII instead).

This post seem to be repetitive, but in C++, the most basic pattern to know is RAII.

Learn to use smart pointers, both from boost, TR1 or even the lowly (but often efficient enough) auto_ptr (but you must know its limitations).

RAII is the basis of both exception safety and resource disposal in C++, and no other pattern (sandwich, etc.) will give you both (and most of the time, it will give you none).

See below a comparison of RAII and non RAII code:

void doSandwich()
   T * p = new T() ;
   // do something with p
   delete p ; // leak if the p processing throws or return

void doRAIIDynamic()
   std::auto_ptr<T> p(new T()) ; // you can use other smart pointers, too
   // do something with p
   // WON'T EVER LEAK, even in case of exceptions, returns, breaks, etc.

void doRAIIStatic()
   T p ;
   // do something with p
   // WON'T EVER LEAK, even in case of exceptions, returns, breaks, etc.

About RAII

To summarize (after the comment from Ogre Psalm33), RAII relies on three concepts:

  • Once the object is constructed, it just works! Do acquire resources in the constructor.
  • Object destruction is enough! Do free resources in the destructor.
  • It's all about scopes! Scoped objects (see doRAIIStatic example above) will be constructed at their declaration, and will be destroyed the moment the execution exits the scope, no matter how the exit (return, break, exception, etc.).

This means that in correct C++ code, most objects won't be constructed with new, and will be declared on the stack instead. And for those constructed using new, all will be somehow scoped (e.g. attached to a smart pointer).

As a developer, this is very powerful indeed as you won't need to care about manual resource handling (as done in C, or for some objects in Java which makes intensive use of try/finally for that case)...

Edit (2012-02-12)

"scoped objects ... will be destructed ... no matter the exit" that's not entirely true. there are ways to cheat RAII. any flavour of terminate() will bypass cleanup. exit(EXIT_SUCCESS) is an oxymoron in this regard.


wilhelmtell is quite right about that: There are exceptional ways to cheat RAII, all leading to the process abrupt stop.

Those are exceptional ways because C++ code is not littered with terminate, exit, etc., or in the case with exceptions, we do want an unhandled exception to crash the process and core dump its memory image as is, and not after cleaning.

But we must still know about those cases because, while they rarely happen, they can still happen.

(who calls terminate or exit in casual C++ code?... I remember having to deal with that problem when playing with GLUT: This library is very C-oriented, going as far as actively designing it to make things difficult for C++ developers like not caring about stack allocated data, or having "interesting" decisions about never returning from their main loop... I won't comment about that).

Can I update a JSF component from a JSF backing bean method?

I also tried to update a component from a jsf backing bean/class

You need to do the following after manipulating the UI component:


It is important to use the clientId instead of the (server-side) componentId!!

Git list of staged files

You can Try using :- git ls-files -s

Column count doesn't match value count at row 1

MySQL will also report "Column count doesn't match value count at row 1" if you try to insert multiple rows without delimiting the row sets in the VALUES section with parentheses, like so:

INSERT INTO `receiving_table`
  (1003,'George', 'Boole'),

Is it possible to remove the hand cursor that appears when hovering over a link? (or keep it set as the normal pointer)

cursor: default;

In the above code [cursor:default] is used. Default is the usual arrow cursor that appears.

And if you use [cursor: pointer] then you can access to the hand like cursor that appears when you hover over a link.

To know more about cursors and their appearance click the below link:

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

You might try using display: block or display: inline-block. A nice tutorial can be found here:

CSS - Expand float child DIV height to parent's height

I have recently done this on my website using jQuery. The code calculates the height of the tallest div and sets the other divs to the same height. Here's the technique:

I don't believe height:100% will work, so if you don't explicitly know the div heights I don't think there is a pure CSS solution.

Converting characters to integers in Java


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

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

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

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

-1 if the character has no numeric value.

And here is the link.

convert an enum to another type of enum

I know that's an old question and have a lot of answers, However I find that using a switch statement as in the accepted answer is somewhat cumbersome, so here are my 2 cents:

My personal favorite method is to use a dictionary, where the key is the source enum and the value is the target enum - so in the case presented on the question my code would look like this:

var genderTranslator = new Dictionary<TheirGender, MyGender>();
genderTranslator.Add(TheirGender.Male, MyGender.Male);
genderTranslator.Add(TheirGender.Female, MyGender.Female);
genderTranslator.Add(TheirGender.Unknown, MyGender.Unknown);

// translate their to mine    
var myValue = genderTranslator[TheirValue];

// translate mine to their
var TheirValue = genderTranslator .FirstOrDefault(x => x.Value == myValue).Key;;

Of course, this can be wrapped in a static class and be used as an extension methods:

public static class EnumTranslator

    private static Dictionary<TheirGender, MyGender> GenderTranslator = InitializeGenderTranslator();

    private static Dictionary<TheirGender, MyGender> InitializeGenderTranslator()
        var translator = new Dictionary<TheirGender, MyGender>();
        translator.Add(TheirGender.Male, MyGender.Male);
        translator.Add(TheirGender.Female, MyGender.Female);
        translator.Add(TheirGender.Unknown, MyGender.Unknown);
        return translator;

    public static MyGender Translate(this TheirGender theirValue)
        return GenderTranslator[theirValue];

    public static TheirGender Translate(this MyGender myValue)
        return GenderTranslator.FirstOrDefault(x => x.Value == myValue).Key;


Hibernate - Batch update returned unexpected row count from update: 0 actual row count: 0 expected: 1

i got the same problem and i verified this may occur because of Auto increment primary key. To solve this problem do not inset auto increment value with data set. Insert data without the primary key.

How to force page refreshes or reloads in jQuery?

You can refresh the events after adding new ones by applying the following code: -Release the Events -set Event Source -Re-render Events

                  $('#calendar').fullCalendar('addEventSource', YoureventSource);         
                  $('#calendar').fullCalendar('rerenderEvents' );

That will solve the problem

relative path in require_once doesn't work

In my case it doesn't work, even with __DIR__ or getcwd() it keeps picking the wrong path, I solved by defining a costant in every file I need with the absolute base path of the project:

if(!defined('THISBASEPATH')){ define('THISBASEPATH', '/mypath/'); }
require_once THISBASEPATH.'cache/crud.php';
/*every other require_once you need*/

I have MAMP with php 5.4.10 and my folder hierarchy is basilar:



What are alternatives to document.write?

I fail to see the problem with document.write. If you are using it before the onload event fires, as you presumably are, to build elements from structured data for instance, it is the appropriate tool to use. There is no performance advantage to using insertAdjacentHTML or explicitly adding nodes to the DOM after it has been built. I just tested it three different ways with an old script I once used to schedule incoming modem calls for a 24/7 service on a bank of 4 modems.

By the time it is finished this script creates over 3000 DOM nodes, mostly table cells. On a 7 year old PC running Firefox on Vista, this little exercise takes less than 2 seconds using document.write from a local 12kb source file and three 1px GIFs which are re-used about 2000 times. The page just pops into existence fully formed, ready to handle events.

Using insertAdjacentHTML is not a direct substitute as the browser closes tags which the script requires remain open, and takes twice as long to ultimately create a mangled page. Writing all the pieces to a string and then passing it to insertAdjacentHTML takes even longer, but at least you get the page as designed. Other options (like manually re-building the DOM one node at a time) are so ridiculous that I'm not even going there.

Sometimes document.write is the thing to use. The fact that it is one of the oldest methods in JavaScript is not a point against it, but a point in its favor - it is highly optimized code which does exactly what it was intended to do and has been doing since its inception.

It's nice to know that there are alternative post-load methods available, but it must be understood that these are intended for a different purpose entirely; namely modifying the DOM after it has been created and memory allocated to it. It is inherently more resource-intensive to use these methods if your script is intended to write the HTML from which the browser creates the DOM in the first place.

Just write it and let the browser and interpreter do the work. That's what they are there for.

PS: I just tested using an onload param in the body tag and even at this point the document is still open and document.write() functions as intended. Also, there is no perceivable performance difference between the various methods in the latest version of Firefox. Of course there is a ton of caching probably going on somewhere in the hardware/software stack, but that's the point really - let the machine do the work. It may make a difference on a cheap smartphone though. Cheers!

How to grep, excluding some patterns?

Another solution without chaining grep:

egrep '(^|[^g])loom' ~/projects/**/trunk/src/**/*.@(h|cpp)

Between brackets, you exclude the character g before any occurrence of loom, unless loom is the first chars of the line.

Convert string with commas to array

How to Convert Comma Separated String into an Array in JavaScript?

var string = 'hello, world, test, test2, rummy, words';
var arr = string.split(', '); // split string on comma space
console.log( arr );
["hello", "world", "test", "test2", "rummy", "words"]

For More Examples of convert string to array in javascript using the below ways:

  1. Split() – No Separator:

  2. Split() – Empty String Separator:

  3. Split() – Separator at Beginning/End:

  4. Regular Expression Separator:

  5. Capturing Parentheses:

  6. Split() with Limit Argument

    check out this link ==>

PHP How to fix Notice: Undefined variable:

I would guess your query isn't running as expected and you are getting to the return line with undefined variables.

Also, the way you are doing the variable assignment, you would be overwriting the same variable with each loop iteration, so you wouldn't return the entire result set.

Finally, it seems odd to return a numerically-keyed result set instead of an associatively-keyed one. Consider naming only the fields needed in the SELECT and keeping the key assignments. So something like this:

Function ShowDataPatient($idURL){
       $query =" select * from cmu_list_insurance,cmu_home,cmu_patient where cmu_home.home_id = (select home_id from cmu_patient where patient_hn like '%$idURL%')
                 AND cmu_patient.patient_hn like '%$idURL%'
                 AND cmu_list_insurance.patient_id like (select patient_id from cmu_patient where patient_hn like '%$idURL%') ";

   $result = pg_query($query) or die('Query failed: ' . pg_last_error());

   $return = array();
   while ($row = pg_fetch_array($result)){
       $return[] = $row;

   return $return;

You might also consider opening a question about how to improve your query, is it is pretty heinous as it stands now.

How to view instagram profile picture in full-size?

replace "150x150" with 720x720 and remove /vp/ from the should work.

How to get the children of the $(this) selector?

The direct children is

$('> .child-class', this)

Convert MySql DateTime stamp into JavaScript's Date format

There is a simpler way, sql timestamp string:

2018-07-19 00:00:00

The closest format to timestamp for Date() to receive is the following, so replace blank space for "T":

var dateString = media.intervention.replace(/\s/g, "T");


Then, create the date object:

var date = new Date(dateString);

result would be the date object:

Thu Jul 19 2018 00:00:00 GMT-0300 (Horário Padrão de Brasília)

DataGridView - Focus a specific cell

You can try this for DataGrid:

DataGridCellInfo cellInfo = new DataGridCellInfo(myDataGrid.Items[colRow], myDataGrid.Columns[colNum]);
DataGridCell cellToFocus = (DataGridCell)cellInfo.Column.GetCellContent(cellInfo.Item).Parent;
ViewControlHelper.SetFocus(cellToFocus, e);

Docker for Windows error: "Hardware assisted virtualization and data execution protection must be enabled in the BIOS"

Below is working solution for me, please follow these steps

  1. Open PowerShell as administrator or CMD prompt as administrator

  2. Run this command in PowerShell-> bcdedit /set hypervisorlaunchtype auto

  3. Now restart the system and try again.


import sun.misc.BASE64Encoder results in error compiled in Eclipse

This error is because of you are importing below two classes import sun.misc.BASE64Encoder; import sun.misc.BASE64Decoder;. Maybe you are using encode and decode of that library like below.

new BASE64Encoder().encode(encVal);

Yeah instead of sun.misc.BASE64Encoder you can import java.util.Base64 class.Now change the previous encode method as below:


Now change the previous decode method as below

byte[] base64DecodedData = Base64.getDecoder().decode(base64EncodedData);

Now everything is done , you can save your program and run. It will run without showing any error.

Property 'value' does not exist on type 'Readonly<{}>'

According to the official ReactJs documentation, you need to pass argument in the default format witch is:

P = {} // default for your props
S = {} // default for yout state

interface Component<P = {}, S = {}> extends ComponentLifecycle<P, S> { }

Or to define your own type like below: (just an exp)

interface IProps {
    clients: Readonly<IClientModel[]>;

    onSubmit: (data: IClientModel) => void;

interface IState {
   clients: Readonly<IClientModel[]>;
   loading: boolean;

class ClientsPage extends React.Component<IProps, IState> {
  // ...

typescript and react whats react component P S mean

how to statically type react components with typescript

Server.Mappath in C# classlibrary

Maybe you could abstract this as a dependency and create an IVirtualPathResolver. This way your service classes wouldn't be bound to System.Web and you could create another implementation if you wanted to reuse your logic in a different UI technology.

Run .php file in Windows Command Prompt (cmd)

You should declare Environment Variable for PHP in path, so you could use like this:

C:\Path\to\somewhere>php cli.php

You can do it like this

Select an Option from the Right-Click Menu in Selenium Webdriver - Java

To select the item from the contextual menu, you have to just move your mouse positions with the use of Key down event like this:-

Actions action= new Actions(driver);

hope this will works for you. Have a great day :)

Lollipop : draw behind statusBar with its color set to transparent

@Cody Toombs's answer lead to an issue that brings the layout behind the navigation bar. So what I found is using this solution given by @Kriti

here is the Kotlin code snippet for the same:

if (Build.VERSION.SDK_INT >= 19 && Build.VERSION.SDK_INT < 21) {
    setWindowFlag(this, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS, true)

if (Build.VERSION.SDK_INT >= 19) {
    window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_LAYOUT_STABLE or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN

if (Build.VERSION.SDK_INT >= 21) {
    setWindowFlag(this, WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS, false)

private fun setWindowFlag(activity: Activity, bits: Int, on: Boolean) {

    val win: Window = activity.getWindow()

    val winParams: WindowManager.LayoutParams = win.getAttributes()
    if (on) {
        winParams.flags = winParams.flags or bits
    } else {
        winParams.flags = winParams.flags and bits.inv()

You also need to add


root view of your layout.

Customize UITableView header section

Full 2019 example to copy and paste

First set "Grouped" on storyboard: it has to happen at init time, you can't really set it later, so it's easier to remember to do it on storyboard:

enter image description here


Must implement heightForHeaderInSection due to Apple bug.

func tableView(_ tableView: UITableView,
                   heightForHeaderInSection section: Int) -> CGFloat {
    return CGFloat(70.0)

There is still an Apple bug - for ten years now - where it simply won't show the first header (i.e., index 0) if you don't have heightForHeaderInSection call.

So, tableView.sectionHeaderHeight = 70 simply doesn't work, it's broken.

Setting a frame achieves nothing:

In viewForHeaderInSection simply create a UIView().

It is pointless / achieves nothing if you UIView(frame ...) since iOS simply sets the size of the view as determined by the table.

So the first line of viewForHeaderInSection will be simply let view = UIView() and that is the view you return.

func tableView(_ tableView: UITableView,
                       viewForHeaderInSection section: Int) -> UIView? {
    let view = UIView()
    let l = UILabel()
    l.backgroundColor = .systemOrange
    l.font = UIFont.systemFont(ofSize: 15)
    l.textColor = .yourClientsFavoriteColor
    switch section {
    case 0:
        l.text =  "First section on screen"
    case 1:
        l.text =  "Here's the second section"
        l.text =  ""
    return view

That's it - anything else is a time waste.

Another "fussy" Apple issue.

The convenience extension used above is:

extension UIView {
    // incredibly useful:
    func bindEdgesToSuperview() {
        guard let s = superview else {
            preconditionFailure("`superview` nil in bindEdgesToSuperview")
        translatesAutoresizingMaskIntoConstraints = false
        leadingAnchor.constraint(equalTo: s.leadingAnchor).isActive = true
        trailingAnchor.constraint(equalTo: s.trailingAnchor).isActive = true
        topAnchor.constraint(equalTo: s.topAnchor).isActive = true
        bottomAnchor.constraint(equalTo: s.bottomAnchor).isActive = true

Swift - How to convert String to Double

You can use StringEx. It extends String with string-to-number conversions including toDouble().

extension String {
    func toDouble() -> Double?

It verifies the string and fails if it can't be converted to double.


import StringEx

let str = "123.45678"
if let num = str.toDouble() {
    println("Number: \(num)")
} else {
    println("Invalid string")

Deactivate or remove the scrollbar on HTML

Meder Omuraliev suggested to use an event handler and set scrollTo(0,0). This is an example for Wassim-azirar. Bringing it all together, I assume this is the final solution.

We have 3 problems: the scrollbar, scrolling with mouse, and keyboard. This hides the scrollbar:

       html, body{overflow:hidden;}

Unfortunally, you can still scroll with the keyboard: To prevent this, we can:

    function keydownHandler(e) {
var evt = e ? e:event;
  var keyCode = evt.keyCode;

  if (keyCode==38 || keyCode==39 || keyCode==40 || keyCode==37){ //arrow keys


The scrolling with the mouse just naturally doesn't work after this code, so we have prevented the scrolling.

For example:

How to remove origin from git repository

Remove existing origin and add new origin to your project directory

>$ git remote show origin

>$ git remote rm origin

>$ git add .

>$ git commit -m "First commit"

>$ git remote add origin Copied_origin_url

>$ git remote show origin

>$ git push origin master

python: get directory two levels up

(pathlib.Path('../../') ).resolve()

android: stretch image in imageview to fit screen

The accepted answer is perfect, however if you want to do it from xml, you can use android:scaleType="fitXY"

Protractor : How to wait for page complete after click a button?

Use this I think it's better




For you to use this setting of isAngularSite should put this in your protractor.conf.js here:

        global.isAngularSite = function(flag) {
        browser.ignoreSynchronization = !flag;

ssl_error_rx_record_too_long and Apache SSL

In my case I had forgot to set SSLEngine On in the configuration. Like so,

<VirtualHost _default_:443>
  SSLEngine On

ls command: how can I get a recursive full-path listing, one line per file?

If you really want to use ls, then format its output using awk:

ls -R /path | awk '
NF&&f{ print s"/"$0 }'

The type or namespace cannot be found (are you missing a using directive or an assembly reference?)

I get this error when my project .net framework version does not match the framework version of the DLL I am linking to. In my case, I was getting:

"The type or namespace name 'UserVoice' could not be found (are you missing a using directive or an assembly reference?).

UserVoice was .Net 4.0, and my project properties were set to ".Net 4.0 Client Profile". Changing to .Net 4.0 on the project cleared the error. I hope this helps someone.

Pandas merge two dataframes with different columns

I had this problem today using any of concat, append or merge, and I got around it by adding a helper column sequentially numbered and then doing an outer join

for i in df1.index:
for i in df2.index:

How to remove single character from a String

If you need some logical control over character removal, use this

String string = "sdsdsd";
char[] arr = string.toCharArray();
// Run loop or whatever you need
String ss = new String(arr);

If you don't need any such control, you can use what Oscar orBhesh mentioned. They are spot on.

How to query the permissions on an Oracle directory?

You can see all the privileges for all directories wit the following

from all_tab_privs
where table_name in
  (select directory_name 
   from dba_directories);

The following gives you the sql statements to grant the privileges should you need to backup what you've done or something

select 'Grant '||privilege||' on directory '||table_schema||'.'||table_name||' to '||grantee 
from all_tab_privs 
where table_name in (select directory_name from dba_directories);

How to Retrieve value from JTextField in Java Swing?

How do we retrieve a value from a text field?


ActionListner example:


public void actionPerformed(ActionEvent evt) {
    String text = textField.getText();
    textArea.append(text + newline);

How to get the fields in an Object via reflection?

Here's a quick and dirty method that does what you want in a generic way. You'll need to add exception handling and you'll probably want to cache the BeanInfo types in a weakhashmap.

public Map<String, Object> getNonNullProperties(final Object thingy) {
    final Map<String, Object> nonNullProperties = new TreeMap<String, Object>();
    try {
        final BeanInfo beanInfo = Introspector.getBeanInfo(thingy
        for (final PropertyDescriptor descriptor : beanInfo
                .getPropertyDescriptors()) {
            try {
                final Object propertyValue = descriptor.getReadMethod()
                if (propertyValue != null) {
            } catch (final IllegalArgumentException e) {
                // handle this please
            } catch (final IllegalAccessException e) {
                // and this also
            } catch (final InvocationTargetException e) {
                // and this, too
    } catch (final IntrospectionException e) {
        // do something sensible here
    return nonNullProperties;

See these references: