Programs & Examples On #Xmldatasource

How to programmatically set SelectedValue of Dropdownlist when it is bound to XmlDataSource

DropDownList1.Items.FindByValue(stringValue).Selected = true; 

should work.

PHP code is not being executed, instead code shows on the page

in my case (Apache/2.4.34),

after uncommenting the specific module

"LoadModule php7_module libexec/apache2/libphp7.so"

from

"/etc/apache2/httpd.conf"

my problem was gone.

How can I convert a series of images to a PDF from the command line on linux?

Use convert from http://www.imagemagick.org. (Readily supplied as a package in most Linux distributions.)

Spring: return @ResponseBody "ResponseEntity<List<JSONObject>>"

Instead of

return new ResponseEntity<JSONObject>(entities, HttpStatus.OK);

try

return new ResponseEntity<List<JSONObject>>(entities, HttpStatus.OK);

Programmatically retrieve SQL Server stored procedure source that is identical to the source returned by the SQL Server Management Studio gui?

Use the following select statement to get the whole definition:

select ROUTINE_DEFINITION 
  from INFORMATION_SCHEMA.ROUTINES 
 where ROUTINE_NAME = 'someprocname'

I guess that SSMS and other tools read this out and make changes where necessary, such as changing CREATE to ALTER. As far as I know, SQL stores not other representations of the procedure.

What is the reason behind "non-static method cannot be referenced from a static context"?

The method you are trying to call is an instance-level method; you do not have an instance.

static methods belong to the class, non-static methods belong to instances of the class.

gcloud command not found - while installing Google Cloud SDK

To launch it on MacOs Sierra, after install gcloud I modified my .bash_profile

Original lines:

# The next line updates PATH for the Google Cloud SDK.
if [ -f '/Users/alejandro/google-cloud-sdk/path.bash.inc' ]; then . '/Users/alejandro/google-cloud-sdk/path.bash.inc'; fi

# The next line enables shell command completion for gcloud.
if [ -f '/Users/alejandro/google-cloud-sdk/completion.bash.inc' ]; then . '/Users/alejandro/google-cloud-sdk/completion.bash.inc'; fi

updated to:

# The next line updates PATH for the Google Cloud SDK.
if [ -f '/Users/alejandro/google-cloud-sdk/path.bash.inc' ]; then source '/Users/alejandro/google-cloud-sdk/path.bash.inc'; fi

# The next line enables shell command completion for gcloud.
if [ -f '/Users/alejandro/google-cloud-sdk/completion.bash.inc' ]; then source '/Users/alejandro/google-cloud-sdk/completion.bash.inc'; fi

Restart the terminal and all become to work as expected!

SQL grouping by all the columns

The DISTINCT Keyword


I believe what you are trying to do is:

SELECT DISTINCT * FROM MyFooTable;

If you group by all columns, you are just requesting that duplicate data be removed.

For example a table with the following data:

 id |     value      
----+----------------
  1 | foo
  2 | bar
  1 | foo
  3 | something else

If you perform the following query which is essentially the same as SELECT * FROM MyFooTable GROUP BY * if you are assuming * means all columns:

SELECT * FROM MyFooTable GROUP BY id, value;

 id |     value      
----+----------------
  1 | foo
  3 | something else
  2 | bar

It removes all duplicate values, which essentially makes it semantically identical to using the DISTINCT keyword with the exception of the ordering of results. For example:

SELECT DISTINCT * FROM MyFooTable;

 id |     value      
----+----------------
  1 | foo
  2 | bar
  3 | something else

Can I apply the required attribute to <select> fields in HTML5?

You can use the selected attribute for the option element to select a choice by default. You can use the required attribute for the select element to ensure that the user selects something.

In Javascript, you can check the selectedIndex property to get the index of the selected option, or you can check the value property to get the value of the selected option.

According to the HTML5 spec, selectedIndex "returns the index of the first selected item, if any, or -1 if there is no selected item. And value "returns the value of the first selected item, if any, or the empty string if there is no selected item." So if selectedIndex = -1, then you know they haven't selected anything.

<button type="button" onclick="displaySelection()">What did I pick?</button>
<script>
    function displaySelection()
    {
        var mySelect = document.getElementById("someSelectElement");
        var mySelection = mySelect.selectedIndex;
        alert(mySelection);
    }
</script>

SQL Server : converting varchar to INT

This is more for someone Searching for a result, than the original post-er. This worked for me...

declare @value varchar(max) = 'sad';
select sum(cast(iif(isnumeric(@value) = 1, @value, 0) as bigint));

returns 0

declare @value varchar(max) = '3';
select sum(cast(iif(isnumeric(@value) = 1, @value, 0) as bigint));

returns 3

Converting a string to a date in DB2

Okay, seems like a bit of a hack. I have got it to work using a substring, so that only the part of the string with the date (not the time) gets passed into the DATE function...

DATE(substr(SETTLEMENTDATE.VALUE,7,4)||'-'|| substr(SETTLEMENTDATE.VALUE,4,2)||'-'|| substr(SETTLEMENTDATE.VALUE,1,2))

I will still accept any answers that are better than this one!

ggplot geom_text font size control

Here are a few options for changing text / label sizes

library(ggplot2)

# Example data using mtcars

a <- aggregate(mpg ~ vs + am , mtcars, function(i) round(mean(i)))

p <- ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) + 
            geom_bar(stat="identity",position="dodge") + 
            geom_text(data = a, aes(label = mpg), 
                            position = position_dodge(width=0.9),  size=20)

The size in the geom_text changes the size of the geom_text labels.

p <- p + theme(axis.text = element_text(size = 15)) # changes axis labels

p <- p + theme(axis.title = element_text(size = 25)) # change axis titles

p <- p + theme(text = element_text(size = 10)) # this will change all text size 
                                                             # (except geom_text)


For this And why size of 10 in geom_text() is different from that in theme(text=element_text()) ?

Yes, they are different. I did a quick manual check and they appear to be in the ratio of ~ (14/5) for geom_text sizes to theme sizes.

So a horrible fix for uniform sizes is to scale by this ratio

geom.text.size = 7
theme.size = (14/5) * geom.text.size

ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) + 
  geom_bar(stat="identity",position="dodge") + 
  geom_text(data = a, aes(label = mpg), 
            position = position_dodge(width=0.9),  size=geom.text.size) + 
  theme(axis.text = element_text(size = theme.size, colour="black")) 

This of course doesn't explain why? and is a pita (and i assume there is a more sensible way to do this)

Jquery Open in new Tab (_blank)

you cannot set target attribute to div, becacuse div does not know how to handle http requests. instead of you set target attribute for link tag.

$(this).find("a").target = "_blank";
window.location= $(this).find("a").attr("href")

Linux Command History with date and time

Try this:

> HISTTIMEFORMAT="%d/%m/%y %T "

> history

You can adjust the format to your liking, of course.

How do I see active SQL Server connections?

Click the "activity monitor" icon in the toolbar.

From Thorsten's comment:

In SQL Server Management Studio, right click on Server, choose "Activity Monitor" from context menu -or- use keyboard shortcut Ctrl + Alt + A.

Reference: Microsoft Docs - Open Activity Monitor in SQL Server Management Studio (SSMS)

How do I send a JSON string in a POST request in Go

you can just use post to post your json.

values := map[string]string{"username": username, "password": password}

jsonValue, _ := json.Marshal(values)

resp, err := http.Post(authAuthenticatorUrl, "application/json", bytes.NewBuffer(jsonValue))

How to print to console when using Qt

It also has a syntax similar to prinft, e.g.:

qDebug ("message %d, says: %s",num,str); 

Very handy as well

How to make node.js require absolute? (instead of relative)

Manual Symlinks (and Windows Junctions)

Couldn't the examples directory contain a node_modules with a symbolic link to the root of the project project -> ../../ thus allowing the examples to use require('project'), although this doesn't remove the mapping, it does allow the source to use require('project') rather than require('../../').

I have tested this, and it does work with v0.6.18.

Listing of project directory:

$ ls -lR project
project:
drwxr-xr-x 3 user user 4096 2012-06-02 03:51 examples
-rw-r--r-- 1 user user   49 2012-06-02 03:51 index.js

project/examples:
drwxr-xr-x 2 user user 4096 2012-06-02 03:50 node_modules
-rw-r--r-- 1 user user   20 2012-06-02 03:51 test.js

project/examples/node_modules:
lrwxrwxrwx 1 user user 6 2012-06-02 03:50 project -> ../../

The contents of index.js assigns a value to a property of the exports object and invokes console.log with a message that states it was required. The contents of test.js is require('project').

Automated Symlinks

The problem with manually creating symlinks is that every time you npm ci, you lose the symlink. If you make the symlink process a dependency, viola, no problems.

The module basetag is a postinstall script that creates a symlink (or Windows junction) named $ every time npm install or npm ci is run:

npm install --save basetag
node_modules/$ -> ..

With that, you don't need any special modification to your code or require system. $ becomes the root from which you can require.

var foo = require('$/lib/foo.js');

If you don't like the use of $ and would prefer # or something else (except @, which is a special character for npm), you could fork it and make the change.

Note: Although Windows symlinks (to files) require admin permissions, Windows junctions (to directories) do not need Windows admin permissions. This is a safe, reliable, cross-platform solution.

Different ways of clearing lists

There is a very simple way to clear a python list. Use del list_name[:].

For example:

>>> a = [1, 2, 3]
>>> b = a
>>> del a[:]
>>> print a, b
[] []

Changing the tmp folder of mysql

Here is an example to move the mysqld tmpdir from /tmp to /run/mysqld which already exists on Ubuntu 13.04 and is a tmpfs (memory/ram):

sudo vim /etc/mysql/conf.d/local.cnf

Add:

[mysqld]
tmpdir = /run/mysqld

Then:

sudo service mysql restart

Verify:

SHOW VARIABLES LIKE 'tmpdir';

==================================================================

If you get an error on MySQL restart, you may have AppArmor enabled:

sudo vim /etc/apparmor.d/local/usr.sbin.mysqld

Add:

# Site-specific additions and overrides for usr.sbin.mysqld.
# For more details, please see /etc/apparmor.d/local/README.
/run/mysqld/ r,
/run/mysqld/** rwk,

Then:

sudo service apparmor reload 

sources: http://2bits.com/articles/reduce-your-servers-resource-usage-moving-mysql-temporary-directory-ram-disk.html, https://blogs.oracle.com/jsmyth/entry/apparmor_and_mysql

Array initialization in Perl

If I understand you, perhaps you don't need an array of zeroes; rather, you need a hash. The hash keys will be the values in the other array and the hash values will be the number of times the value exists in the other array:

use strict;
use warnings;

my @other_array = (0,0,0,1,2,2,3,3,3,4);
my %tallies;
$tallies{$_} ++ for @other_array;

print "$_ => $tallies{$_}\n" for sort {$a <=> $b} keys %tallies;    

Output:

0 => 3
1 => 1
2 => 2
3 => 3
4 => 1

To answer your specific question more directly, to create an array populated with a bunch of zeroes, you can use the technique in these two examples:

my @zeroes = (0) x 5;            # (0,0,0,0,0)

my @zeroes = (0) x @other_array; # A zero for each item in @other_array.
                                 # This works because in scalar context
                                 # an array evaluates to its size.

Adding image to JFrame

If you are using Netbeans to develop, use jLabel and change it's icon property.

How do I import from Excel to a DataSet using Microsoft.Office.Interop.Excel?

object[,] valueArray = (object[,])excelRange.get_Value(XlRangeValueDataType.xlRangeValueDefault);

//Get the column names
for (int k = 0; k < valueArray.GetLength(1); )
{
    //add columns to the data table.
    dt.Columns.Add((string)valueArray[1,++k]);
}

//Load data into data table
object[] singleDValue = new object[valueArray.GetLength(1)];
//value array first row contains column names. so loop starts from 1 instead of 0
for (int i = 1; i < valueArray.GetLength(0); i++)
{
    Console.WriteLine(valueArray.GetLength(0) + ":" + valueArray.GetLength(1));
    for (int k = 0; k < valueArray.GetLength(1); )
    {
        singleDValue[k] = valueArray[i+1, ++k];
    }
    dt.LoadDataRow(singleDValue, System.Data.LoadOption.PreserveChanges);
}

Deleting an SVN branch

Assuming this branch isn't an external or a symlink, removing the branch should be as simple as:

svn rm branches/< mybranch >

svn ci -m "message"

If you'd like to do this in the repository then update to remove it from your working copy you can do something like:

svn rm http://< myurl >/< myrepo >/branches/< mybranch >

Then run:

svn update

laravel-5 passing variable to JavaScript

One working example for me.

Controller:

public function tableView()
{
    $sites = Site::all();
    return view('main.table', compact('sites'));
}

View:

<script>    
    var sites = {!! json_encode($sites->toArray()) !!};
</script>

To prevent malicious / unintended behaviour, you can use JSON_HEX_TAG as suggested by Jon in the comment that links to this SO answer

<script>    
    var sites = {!! json_encode($sites->toArray(), JSON_HEX_TAG) !!};
</script>

Convert HttpPostedFileBase to byte[]

As Darin says, you can read from the input stream - but I'd avoid relying on all the data being available in a single go. If you're using .NET 4 this is simple:

MemoryStream target = new MemoryStream();
model.File.InputStream.CopyTo(target);
byte[] data = target.ToArray();

It's easy enough to write the equivalent of CopyTo in .NET 3.5 if you want. The important part is that you read from HttpPostedFileBase.InputStream.

For efficient purposes you could check whether the stream returned is already a MemoryStream:

byte[] data;
using (Stream inputStream = model.File.InputStream)
{
    MemoryStream memoryStream = inputStream as MemoryStream;
    if (memoryStream == null)
    {
        memoryStream = new MemoryStream();
        inputStream.CopyTo(memoryStream);
    }
    data = memoryStream.ToArray();
}

How to unescape HTML character entities in Java?

The libraries mentioned in other answers would be fine solutions, but if you already happen to be digging through real-world html in your project, the Jsoup project has a lot more to offer than just managing "ampersand pound FFFF semicolon" things.

// textValue: <p>This is a&nbsp;sample. \"Granny\" Smith &#8211;.<\/p>\r\n
// becomes this: This is a sample. "Granny" Smith –.
// with one line of code:
// Jsoup.parse(textValue).getText(); // for older versions of Jsoup
Jsoup.parse(textValue).text();

// Another possibility may be the static unescapeEntities method:
boolean strictMode = true;
String unescapedString = org.jsoup.parser.Parser.unescapeEntities(textValue, strictMode);

And you also get the convenient API for extracting and manipulating data, using the best of DOM, CSS, and jquery-like methods. It's open source and MIT licence.

Check if a div does NOT exist with javascript

getElementById returns null if there is no such element.

In Mongoose, how do I sort by date? (node.js)

Sorting in Mongoose has evolved over the releases such that some of these answers are no longer valid. As of the 4.1.x release of Mongoose, a descending sort on the date field can be done in any of the following ways:

    Room.find({}).sort('-date').exec((err, docs) => { ... });
    Room.find({}).sort({date: -1}).exec((err, docs) => { ... });
    Room.find({}).sort({date: 'desc'}).exec((err, docs) => { ... });
    Room.find({}).sort({date: 'descending'}).exec((err, docs) => { ... });
    Room.find({}).sort([['date', -1]]).exec((err, docs) => { ... });
    Room.find({}, null, {sort: '-date'}, (err, docs) => { ... });
    Room.find({}, null, {sort: {date: -1}}, (err, docs) => { ... });

For an ascending sort, omit the - prefix on the string version or use values of 1, asc, or ascending.

How to call a method in another class in Java?

in School,

public void addTeacherName(classroom classroom, String teacherName) {
    classroom.setTeacherName(teacherName);
}

BTW, use Pascal Case for class names. Also, I would suggest a Map<String, classroom> to map a classroom name to a classroom.

Then, if you use my suggestion, this would work

public void addTeacherName(String className, String teacherName) {
    classrooms.get(className).setTeacherName(teacherName);
}

Changing nav-bar color after scrolling?

I've recently done it slightly different to some of the examples above so thought I'd share, albeit very late!

Firstly the HTML, note there is only one class within the header:

<body>

<header class="GreyHeader">
</header>


</body>

And the CSS:

body {
height: 3000px;
}

.GreyHeader{
height: 200px; 
background-color: rgba(107,107,107,0.66);
position: fixed;
top:200;
width: 100%;

}

.FireBrickRed {
height: 100px;
background-color: #b22222;
position: fixed;
top:200;
width: 100%;
}

.transition {
  -webkit-transition: height 2s; /* For Safari 3.1 to 6.0 */
  transition: height 2s;
}

The html uses only the class .greyHeader but within the CSS I have created another class to call once the scroll has reached a certain point from the top:

$(function() {
    var header = $(".GreyHeader");
    $(window).scroll(function() {    
        var scroll = $(window).scrollTop();

        if (scroll >= 500) {
            header.removeClass('GreyHeader').addClass("FireBrickRed ");
            header.addClass("transition");
        } else {
            header.removeClass("FireBrickRed ").addClass('GreyHeader');
            header.addClass("transition");
        }
    });
});

check this fiddle: https://jsfiddle.net/29y64L7d/1/

Get domain name

If you want specific users to have access to all or part of the WMI object space, you need to permission them as shown here. Note that you have to be running on as an admin to perform this setting.

Is this very likely to create a memory leak in Tomcat?

The key "Transactional Resources" looks like you are talking to the database without a proper transaction. Make sure transaction management is configured properly and no invocation path to the DAO exists that doesn't run under a @Transactional annotation. This can easily happen when you configured transaction management on the Controller level but are invoking DAOs in a timer or are using @PostConstruct annotations. I wrote it up here http://georgovassilis.blogspot.nl/2014/01/tomcat-spring-and-memory-leaks-when.html

Edit: It looks like this is (also?) a bug with spring-data-jpa which has been fixed with v1.4.3. I looked it up in the spring-data-jpa sources of LockModeRepositoryPostProcessor which sets the "Transactional Resources" key. In 1.4.3 it also clears the key again.

git push vs git push origin <branchname>

The first push should be a:

git push -u origin branchname

That would make sure:

Any future git push will, with that default policy, only push the current branch, and only if that branch has an upstream branch with the same name.
that avoid pushing all matching branches (previous default policy), where tons of test branches were pushed even though they aren't ready to be visible on the upstream repo.

Android: how to convert whole ImageView to Bitmap?

try {
        photo.setImageURI(Uri.parse("Location");
        BitmapDrawable drawable = (BitmapDrawable) photo.getDrawable();
        Bitmap bitmap = drawable.getBitmap();
        bitmap = Bitmap.createScaledBitmap(bitmap, 70, 70, true);
        photo.setImageBitmap(bitmap);

    } catch (Exception e) {

    }

file_get_contents() how to fix error "Failed to open stream", "No such file"

We can solve this issue by using Curl....

function my_curl_fun($url) {
 $ch = curl_init();
 curl_setopt($ch, CURLOPT_URL, $url);
 curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
 $data = curl_exec($ch);
 curl_close($ch);
 return $data;
}

$feed = 'http://................'; /* Insert URL here */
$data = my_curl_fun($feed);

How to debug a stored procedure in Toad?

Basic Steps to Debug a Procedure in Toad

  1. Load your Procedure in Toad Editor.
  2. Put debug point on the line where you want to debug.See the first screenshot.
  3. Right click on the editor Execute->Execute PLSQL(Debugger).See the second screeshot.
  4. A window opens up,you need to select the procedure from the left side and pass parameters for that procedure and then click Execute.See the third screenshot.
  5. Now start your debugging check Debug-->Step Over...Add Watch etc.

Reference:Toad Debugger

Debug

Execute In Debug

parameter

How to animate RecyclerView items when they appear

Just extends your Adapter like below

public class RankingAdapter extends AnimatedRecyclerView<RankingAdapter.ViewHolder> 

And add super method to onBindViewHolder

@Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        super.onBindViewHolder(holder, position);

It's automate way to create animated adapter like "Basheer AL-MOMANI"

import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.ScaleAnimation;

import java.util.Random;

/**
 * Created by eliaszkubala on 24.02.2017.
 */
public class AnimatedRecyclerView<T extends RecyclerView.ViewHolder> extends RecyclerView.Adapter<T> {


    @Override
    public T onCreateViewHolder(ViewGroup parent, int viewType) {
        return null;
    }

    @Override
    public void onBindViewHolder(T holder, int position) {
        setAnimation(holder.itemView, position);
    }

    @Override
    public int getItemCount() {
        return 0;
    }

    protected int mLastPosition = -1;

    protected void setAnimation(View viewToAnimate, int position) {
        if (position > mLastPosition) {
            ScaleAnimation anim = new ScaleAnimation(0.0f, 1.0f, 0.0f, 1.0f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
            anim.setDuration(new Random().nextInt(501));//to make duration random number between [0,501)
            viewToAnimate.startAnimation(anim);
            mLastPosition = position;
        }
    }

}

Cannot find module cv2 when using OpenCV

First do run these commands inside Terminal/CMD:

conda update anaconda-navigator  
conda update navigator-updater  

Then the issue for the instruction below will be resolved

For windows if you have anaconda installed, you can simply do

pip install opencv-python

or

conda install -c https://conda.binstar.org/menpo opencv

if you are on linux you can do :

pip install opencv-python

or

conda install opencv 

Link1 Link2

For python3.5+ check these links : Link3 , Link4

Update:
if you use anaconda, you may simply use this as well (and hence don't need to add menpo channel):

conda install -c conda-forge opencv

How to repeat last command in python interpreter shell?

You don't need a custom script like pyfunc's answer for OSX (at least on mavericks). In Idle click on Idle -> Preferences -> Keys, locate "history-next" and "history-previous", and either leave them with their default keyboard shortcut or assign "up arrow" and "down arrow" per typical expected terminal behavior.

This is on Idle 2.7 on OSX Mavericks.

typesafe select onChange event using reactjs and typescript

In addition to @thoughtrepo's answer:

Until we do not have definitely typed events in React it might be useful to have a special target interface for input controls:

export interface FormControlEventTarget extends EventTarget{
    value: string;
}

And then in your code cast to this type where is appropriate to have IntelliSense support:

 import {FormControlEventTarget} from "your.helper.library"

 (event.target as FormControlEventTarget).value;

How to fix "Headers already sent" error in PHP

This error message gets triggered when anything is sent before you send HTTP headers (with setcookie or header). Common reasons for outputting something before the HTTP headers are:

  • Accidental whitespace, often at the beginning or end of files, like this:

     <?php
    // Note the space before "<?php"
    ?>
    

       To avoid this, simply leave out the closing ?> - it's not required anyways.

  • Byte order marks at the beginning of a php file. Examine your php files with a hex editor to find out whether that's the case. They should start with the bytes 3F 3C. You can safely remove the BOM EF BB BF from the start of files.
  • Explicit output, such as calls to echo, printf, readfile, passthru, code before <? etc.
  • A warning outputted by php, if the display_errors php.ini property is set. Instead of crashing on a programmer mistake, php silently fixes the error and emits a warning. While you can modify the display_errors or error_reporting configurations, you should rather fix the problem.
    Common reasons are accesses to undefined elements of an array (such as $_POST['input'] without using empty or isset to test whether the input is set), or using an undefined constant instead of a string literal (as in $_POST[input], note the missing quotes).

Turning on output buffering should make the problem go away; all output after the call to ob_start is buffered in memory until you release the buffer, e.g. with ob_end_flush.

However, while output buffering avoids the issues, you should really determine why your application outputs an HTTP body before the HTTP header. That'd be like taking a phone call and discussing your day and the weather before telling the caller that he's got the wrong number.

Playing .mp3 and .wav in Java?

To add MP3 reading support to Java Sound, add the mp3plugin.jar of the JMF to the run-time class path of the application.

Note that the Clip class has memory limitations that make it unsuitable for more than a few seconds of high quality sound.

Why shouldn't I use mysql_* functions in PHP?

There are many reasons, but perhaps the most important one is that those functions encourage insecure programming practices because they do not support prepared statements. Prepared statements help prevent SQL injection attacks.

When using mysql_* functions, you have to remember to run user-supplied parameters through mysql_real_escape_string(). If you forget in just one place or if you happen to escape only part of the input, your database may be subject to attack.

Using prepared statements in PDO or mysqli will make it so that these sorts of programming errors are more difficult to make.

Datetime in where clause

Use a convert function to get all entries for a particular day.

Select * from tblErrorLog where convert(date,errorDate,101) = '12/20/2008'

See CAST and CONVERT for more info

How do I enable C++11 in gcc?

H2CO3 is right, you can use a makefile with the CXXFLAGS set with -std=c++11 A makefile is a simple text file with instructions about how to compile your program. Create a new file named Makefile (with a capital M). To automatically compile your code just type the make command in a terminal. You may have to install make.

Here's a simple one :

CXX=clang++
CXXFLAGS=-g -std=c++11 -Wall -pedantic
BIN=prog

SRC=$(wildcard *.cpp)
OBJ=$(SRC:%.cpp=%.o)

all: $(OBJ)
    $(CXX) -o $(BIN) $^

%.o: %.c
    $(CXX) $@ -c $<

clean:
    rm -f *.o
    rm $(BIN)

It assumes that all the .cpp files are in the same directory as the makefile. But you can easily tweak your makefile to support a src, include and build directories.

Edit : I modified the default c++ compiler, my version of g++ isn't up-to-date. With clang++ this makefile works fine.

jQuery select element in parent window

Use the context-parameter

$("#testdiv",parent.document)

But if you really use a popup, you need to access opener instead of parent

$("#testdiv",opener.document)

C - gettimeofday for computing time?

No. gettimeofday should NEVER be used to measure time.

This is causing bugs all over the place. Please don't add more bugs.

How can I use interface as a C# generic type constraint?

Solution A: This combination of constraints should guarantee that TInterface is an interface:

class example<TInterface, TStruct>
    where TStruct : struct, TInterface
    where TInterface : class
{ }

It requires a single struct TStruct as a Witness to proof that TInterface is a struct.

You can use single struct as a witness for all your non-generic types:

struct InterfaceWitness : IA, IB, IC 
{
    public int DoA() => throw new InvalidOperationException();
    //...
}

Solution B: If you don't want to make structs as witnesses you can create an interface

interface ISInterface<T>
    where T : ISInterface<T>
{ }

and use a constraint:

class example<TInterface>
    where TInterface : ISInterface<TInterface>
{ }

Implementation for interfaces:

interface IA :ISInterface<IA>{ }

This solves some of the problems, but requires trust that noone implements ISInterface<T> for non-interface types, but that is pretty hard to do accidentally.

Can a relative sitemap url be used in a robots.txt?

Good technical & logical question my dear friend. No in robots.txt file you can't go with relative URL of the sitemap; you need to go with the complete URL of the sitemap.

It's better to go with "sitemap: https://www.example.com/sitemap_index.xml"

In the above URL after the colon gives space. I also like to support Deepak.

Auto-size dynamic text to fill fixed size container

Most of the other answers use a loop to reduce the font-size until it fits on the div, this is VERY slow since the page needs to re-render the element each time the font changes size. I eventually had to write my own algorithm to make it perform in a way that allowed me to update its contents periodically without freezing the user browser. I added some other functionality (rotating text, adding padding) and packaged it as a jQuery plugin, you can get it at:

https://github.com/DanielHoffmann/jquery-bigtext

simply call

$("#text").bigText();

and it will fit nicely on your container.

See it in action here:

http://danielhoffmann.github.io/jquery-bigtext/

For now it has some limitations, the div must have a fixed height and width and it does not support wrapping text into multiple lines.

I will work on getting an option to set the maximum font-size.

Edit: I have found some more problems with the plugin, it does not handle other box-model besides the standard one and the div can't have margins or borders. I will work on it.

Edit2: I have now fixed those problems and limitations and added more options. You can set maximum font-size and you can also choose to limit the font-size using either width, height or both. I will work into accepting a max-width and max-height values in the wrapper element.

Edit3: I have updated the plugin to version 1.2.0. Major cleanup on the code and new options (verticalAlign, horizontalAlign, textAlign) and support for inner elements inside the span tag (like line-breaks or font-awesome icons.)

Python: converting a list of dictionaries to json

import json

list = [{'id': 123, 'data': 'qwerty', 'indices': [1,10]}, {'id': 345, 'data': 'mnbvc', 'indices': [2,11]}]

Write to json File:

with open('/home/ubuntu/test.json', 'w') as fout:
    json.dump(list , fout)

Read Json file:

with open(r"/home/ubuntu/test.json", "r") as read_file:
    data = json.load(read_file)
print(data)
#list = [{'id': 123, 'data': 'qwerty', 'indices': [1,10]}, {'id': 345, 'data': 'mnbvc', 'indices': [2,11]}]

display: flex not working on Internet Explorer

Internet Explorer doesn't fully support Flexbox due to:

Partial support is due to large amount of bugs present (see known issues).

enter image description here Screenshot and infos taken from caniuse.com

Notes

Internet Explorer before 10 doesn't support Flexbox, while IE 11 only supports the 2012 syntax.

Known issues

  • IE 11 requires a unit to be added to the third argument, the flex-basis property see MSFT documentation.
  • In IE10 and IE11, containers with display: flex and flex-direction: column will not properly calculate their flexed childrens' sizes if the container has min-height but no explicit height property. See bug.
  • In IE10 the default value for flex is 0 0 auto rather than 0 1 auto as defined in the latest spec.
  • IE 11 does not vertically align items correctly when min-height is used. See bug.

Workarounds

Flexbugs is a community-curated list of Flexbox issues and cross-browser workarounds for them. Here's a list of all the bugs with a workaround available and the browsers that affect.

  1. Minimum content sizing of flex items not honored
  2. Column flex items set to align-items: center overflow their container
  3. min-height on a flex container won't apply to its flex items
  4. flex shorthand declarations with unitless flex-basis values are ignored
  5. Column flex items don't always preserve intrinsic aspect ratios
  6. The default flex value has changed
  7. flex-basis doesn't account for box-sizing: border-box
  8. flex-basis doesn't support calc()
  9. Some HTML elements can't be flex containers
  10. align-items: baseline doesn't work with nested flex containers
  11. Min and max size declarations are ignored when wrapping flex items
  12. Inline elements are not treated as flex-items
  13. Importance is ignored on flex-basis when using flex shorthand
  14. Shrink-to-fit containers with flex-flow: column wrap do not contain their items
  15. Column flex items ignore margin: auto on the cross axis
  16. flex-basis cannot be animated
  17. Flex items are not correctly justified when max-width is used

How to style the parent element when hovering a child element?

As mentioned previously "there is no CSS selector for selecting a parent of a selected child".

So you either:


Here is the example for the javascript/jQuery solution

On the javascript side:

$('#my-id-selector-00').on('mouseover', function(){
  $(this).parent().addClass('is-hover');
}).on('mouseout', function(){
  $(this).parent().removeClass('is-hover');
})

And on the CSS side, you'd have something like this:

.is-hover {
  background-color: red;
}

Strtotime() doesn't work with dd/mm/YYYY format

{{ date('d F Y',strtotime($a->dates)) }}

alternative use laravel

\Carbon\Carbon::parse($a->dates)->format('d F Y') }}

Angular2 Material Dialog css, dialog size

Content in md-dialog-content is automatically scrollable.

You can manually set the size in the call to MdDialog.open

let dialogRef = dialog.open(MyComponent, {
  height: '400px',
  width: '600px',
});

Further documentation / examples for scrolling and sizing: https://material.angular.io/components/dialog/overview

Some colors should be determined by your theme. See here for theming docs: https://material.angular.io/guide/theming

If you want to override colors and such, use Elmer's technique of just adding the appropriate css.

Note that you must have the HTML 5 <!DOCTYPE html> on your page for the size of your dialog to fit the contents correctly ( https://github.com/angular/material2/issues/2351 )

Why is printing "B" dramatically slower than printing "#"?

Pure speculation is that you're using a terminal that attempts to do word-wrapping rather than character-wrapping, and treats B as a word character but # as a non-word character. So when it reaches the end of a line and searches for a place to break the line, it sees a # almost immediately and happily breaks there; whereas with the B, it has to keep searching for longer, and may have more text to wrap (which may be expensive on some terminals, e.g., outputting backspaces, then outputting spaces to overwrite the letters being wrapped).

But that's pure speculation.

Check if element is visible in DOM

If we're just collecting basic ways of detecting visibility, let me not forget:

opacity > 0.01; // probably more like .1 to actually be visible, but YMMV

And as to how to obtain attributes:

element.getAttribute(attributename);

So, in your example:

document.getElementById('snDealsPanel').getAttribute('visibility');

But wha? It doesn't work here. Look closer and you'll find that visibility is being updated not as an attribute on the element, but using the style property. This is one of many problems with trying to do what you're doing. Among others: you can't guarantee that there's actually something to see in an element, just because its visibility, display, and opacity all have the correct values. It still might lack content, or it might lack a height and width. Another object might obscure it. For more detail, a quick Google search reveals this, and even includes a library to try solving the problem. (YMMV)

Check out the following, which are possible duplicates of this question, with excellent answers, including some insight from the mighty John Resig. However, your specific use-case is slightly different from the standard one, so I'll refrain from flagging:

(EDIT: OP SAYS HE'S SCRAPING PAGES, NOT CREATING THEM, SO BELOW ISN'T APPLICABLE) A better option? Bind the visibility of elements to model properties and always make visibility contingent on that model, much as Angular does with ng-show. You can do that using any tool you want: Angular, plain JS, whatever. Better still, you can change the DOM implementation over time, but you'll always be able to read state from the model, instead of the DOM. Reading your truth from the DOM is Bad. And slow. Much better to check the model, and trust in your implementation to ensure that the DOM state reflects the model. (And use automated testing to confirm that assumption.)

Get the value of checked checkbox?

In my project, I usually use this snippets:

var type[];
$("input[name='messageCheckbox']:checked").each(function (i) {
                type[i] = $(this).val();
            });

And it works well.

How to turn on WCF tracing?

The following configuration taken from MSDN can be applied to enable tracing on your WCF service.

<configuration>
  <system.diagnostics>
    <sources>
      <source name="System.ServiceModel"
              switchValue="Information, ActivityTracing"
              propagateActivity="true" >
        <listeners>
             <add name="xml"/>
        </listeners>
      </source>
      <source name="System.ServiceModel.MessageLogging">
        <listeners>
            <add name="xml"/>
        </listeners>
      </source>
      <source name="myUserTraceSource"
              switchValue="Information, ActivityTracing">
        <listeners>
            <add name="xml"/>
        </listeners>
      </source>
    </sources>
    <sharedListeners>
        <add name="xml"
             type="System.Diagnostics.XmlWriterTraceListener"
             initializeData="Error.svclog" />
    </sharedListeners>
  </system.diagnostics>
</configuration>

To view the log file, you can use "C:\Program Files\Microsoft SDKs\Windows\v7.0A\bin\SvcTraceViewer.exe".

If "SvcTraceViewer.exe" is not on your system, you can download it from the "Microsoft Windows SDK for Windows 7 and .NET Framework 4" package here:

Windows SDK Download

You don't have to install the entire thing, just the ".NET Development / Tools" part.

When/if it bombs out during installation with a non-sensical error, Petopas' answer to Windows 7 SDK Installation Failure solved my issue.

What is the best way to filter a Java Collection?

I'll throw RxJava in the ring, which is also available on Android. RxJava might not always be the best option, but it will give you more flexibility if you wish add more transformations on your collection or handle errors while filtering.

Observable.from(Arrays.asList(1, 2, 3, 4, 5))
    .filter(new Func1<Integer, Boolean>() {
        public Boolean call(Integer i) {
            return i % 2 != 0;
        }
    })
    .subscribe(new Action1<Integer>() {
        public void call(Integer i) {
            System.out.println(i);
        }
    });

Output:

1
3
5

More details on RxJava's filter can be found here.

Handling urllib2's timeout? - Python

There are very few cases where you want to use except:. Doing this captures any exception, which can be hard to debug, and it captures exceptions including SystemExit and KeyboardInterupt, which can make your program annoying to use..

At the very simplest, you would catch urllib2.URLError:

try:
    urllib2.urlopen("http://example.com", timeout = 1)
except urllib2.URLError, e:
    raise MyException("There was an error: %r" % e)

The following should capture the specific error raised when the connection times out:

import urllib2
import socket

class MyException(Exception):
    pass

try:
    urllib2.urlopen("http://example.com", timeout = 1)
except urllib2.URLError, e:
    # For Python 2.6
    if isinstance(e.reason, socket.timeout):
        raise MyException("There was an error: %r" % e)
    else:
        # reraise the original error
        raise
except socket.timeout, e:
    # For Python 2.7
    raise MyException("There was an error: %r" % e)

^[A-Za-Z ][A-Za-z0-9 ]* regular expression?

How about

^[A-Za-z]\S*

a letter followed by 0 or more non-space characters (will include all special symbols).

How to wait until WebBrowser is completely loaded in VB.NET?

Another option is to check if it's busy with a timer:

Set the timer as disabled by default. Then whenever navigating, enable it. i.e.:

WebBrowser1.Navigate("https://www.somesite.com")
tmrBusy.Enabled = True

And the timer:

    Private Sub tmrBusy_Tick(sender As Object, e As EventArgs) Handles tmrBusy.Tick

        If WebBrowser1.IsBusy = True Then

            Debug.WriteLine("WB Busy ...")

        Else

            Debug.WriteLine("WB Done.")
            tmrBusy.Enabled = False

        End If

    End Sub

How to hide a column (GridView) but still access its value?

You can do it programmatically:

grid0.Columns[0].Visible = true;
grid0.DataSource = dt;
grid0.DataBind();
grid0.Columns[0].Visible = false;

In this way you set the column to visible before databinding, so the column is generated. The you set the column to not visible, so it is not displayed.

How do I launch the Android emulator from the command line?

open CMD

  1. Open Command Prompt
  2. type the path of emulator in my case

C:\adt-bundle-windows-x86_64-20140702\sdk\tools enter image description here

  1. write "emulator -avd emulatorname" in my case

emulator -avd AdilVD

enter image description here

AsyncTask Android example

Simply:

LongOperation MyTask = new LongOperation();
MyTask.execute();

Java project in Eclipse: The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files

Here is how I solved it: In Java-ADT: Windows - Preference - Java - Installed JREs Just add another JRE, pointing to the 'jre' folder under your JDK folder. (jre is included in the jdk). Make sure you chose the new jre.

Save file Javascript with file name

function saveAs(uri, filename) {
    var link = document.createElement('a');
    if (typeof link.download === 'string') {
        document.body.appendChild(link); // Firefox requires the link to be in the body
        link.download = filename;
        link.href = uri;
        link.click();
        document.body.removeChild(link); // remove the link when done
    } else {
        location.replace(uri);
    }
}

How does DateTime.Now.Ticks exactly work?

You can get the milliseconds since 1/1/1970 using such code:

private static DateTime JanFirst1970 = new DateTime(1970, 1, 1);
public static long getTime()
{
    return (long)((DateTime.Now.ToUniversalTime() - JanFirst1970).TotalMilliseconds + 0.5);
}

How do I get the APK of an installed app without root access?

  1. check the list of installed apk's (following command also list the path where it is installed and package name). adb shell pm list packages -f
  2. use adb pull /package_path/package name /path_in_pc (package path and package name one can get from above command 1.)

Sending event when AngularJS finished loading

i observe DOM manipulation of angular with JQuery and i did set a finish for my app (some sort of predefined and satisfactory situation that i need for my app-abstract) for example i expect my ng-repeater to produce 7 result and there for i will set an observation function with the help of setInterval for this purpose .

$(document).ready(function(){

  var interval = setInterval(function(){

  if($("article").size() == 7){
     myFunction();
     clearInterval(interval);
  }

  },50);

});

How to parse a JSON string into JsonNode in Jackson?

import com.github.fge.jackson.JsonLoader;
JsonLoader.fromString("{\"k1\":\"v1\"}")
== JsonNode = {"k1":"v1"}

Execution Failed for task :app:compileDebugJavaWithJavac in Android Studio

Update (06/05/2017)

I wanted to use Realm for Android and that required Retrolambda. Problem is Retrolambda conflicts with Jack.

So I removed my Jack options config from my gradle shown in original answer below and made the following changes:

// ---------------------------------------------
// Project build.gradle file
// ---------------------------------------------
buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.1'
        classpath 'me.tatarka:gradle-retrolambda:3.6.1'
        classpath "io.realm:realm-gradle-plugin:3.1.4"

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

and

// ---------------------------------------------
// Module build.gradle file
// ---------------------------------------------
apply plugin: 'com.android.application'
apply plugin: 'me.tatarka.retrolambda'
apply plugin: 'realm-android'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    ...

Tools.jar

If you made those changes above and you still get the following error:

Execution failed for task ':app:compileDebugJavaWithJavac'.
com.sun.tools.javac.util.Context.put(Ljava/lang/Class;Ljava/lang/Object;)V

Try removing the following file:

/Library/Java/Extensions/tools.jar 

Then:

  1. Quit emulator
  2. Quit Android Studio
  3. Reopen Android Studio
  4. Build > Clean Project
  5. Run/debug your app onto your device/emulator again

All the changes fixed it for me.

Note:

I am not sure what tools.jar does or whether it's important. Like other uses in this Stackoverflow question:

Can't build Java project on OSX yosemite

We were unfortunate enough to have to use AUSKey (some ancient dinosaur Java authentication key system used by Australian Government to authenticate our computer before we can log into Australian business portal website).

My speculation is tools.jar might have been a JAR file for/by AUSKey.

If you're worried, instead of deleting this file, you can make a backup of the whole folder and save it somewhere just in case you can't login to Australian Business Portal again.

Hope that helps :D

Original Answer

I came across this problem today (27/06/2016).

I downloaded Android Studio 2.2 and updated JDK to 1.8.

In addition to the above answers of pointing to the correct JDK path, I had to additionally specify the JDK version in my build.gradle(Module: app) file:

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

The resulting file looks like this:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.2"
    defaultConfig {
        applicationId "com.mycompany.appname"
        minSdkVersion 17
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

        jackOptions {
            enabled true
        }
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:24.2.1'
    testCompile 'junit:junit:4.12'
}

Please also notice if you came across an error about Java 8 language features requires Jack enabled, you need to add the following to your gradle file (as shown above):

jackOptions {
    enabled true
}

After doing that, I finally got my new project app running on my phone.

How to uninstall a windows service and delete its files without rebooting

(so Windows releases it's hold on the file)

Instead, do Ctrl+Alt+Del right after the Stop of the service and kill the .exe of the service. Than, you can uninstall the service without rebooting. This happened to me in the past and it solves the part that you need to reboot.

How do I check if PHP is connected to a database already?

Try using PHP's mysql_ping function:

echo @mysql_ping() ? 'true' : 'false';

You will need to prepend the "@" to suppose the MySQL Warnings you'll get for running this function without being connected to a database.

There are other ways as well, but it depends on the code that you're using.

Why does IE9 switch to compatibility mode on my website?

I've posted this comment on a seperate StackOverflow thread, but thought it was worth repeating here:

For our in-house ASP.Net app, adding the "X-UA-Compatible" tag on the web page, in the web.config or in the code-behind made absolutely no difference.

The only thing that worked for us was to manually turn off this setting in IE8:

enter image description here

(Sigh.)

This problem only seems to happen with IE8 & IE9 on intranet sites. External websites will work fine and use the correct version of IE8/9, but for internal websites, IE9 suddenly decides it's actually IE7, and doesn't have any HTML 5 support.

No, I don't quite understand this logic either.

My reluctant solution has been to test whether the browser has HTML 5 support (by creating a canvas, and testing if it's valid), and displaying this message to the user if it's not valid:

enter image description here

It's not particularly user-friendly, but getting the user to turn off this annoying setting seems to be the only way to let them run in-house HTML 5 web apps properly.

Or get the users to use Chrome. ;-)

What does .pack() do?

The pack method sizes the frame so that all its contents are at or above their preferred sizes. An alternative to pack is to establish a frame size explicitly by calling setSize or setBounds (which also sets the frame location). In general, using pack is preferable to calling setSize, since pack leaves the frame layout manager in charge of the frame size, and layout managers are good at adjusting to platform dependencies and other factors that affect component size.

From Java tutorial

You should also refer to Javadocs any time you need additional information on any Java API

How to display a jpg file in Python?

from PIL import Image

image = Image.open('File.jpg')
image.show()

How to insert a text at the beginning of a file?

To add a line to the top of the file:

sed -i '1iText to add\'

Populating a ComboBox using C#

Simple way is:

Dictionary<string, string> dict = new Dictionary<string, string>()
{
    {"English ","En" },
    {"Italian  ","It" },
    {"Spainish  ","Sp " }
};

combo.DataSource = new BindingSource(dict, null);
combo.DisplayMember = "Key";
combo.ValueMember = "Value";

Easiest way to convert month name to month number in JS ? (Jan = 01)

If you don't want an array then how about an object?

var months = {
    'Jan' : '01',
    'Feb' : '02',
    'Mar' : '03',
    'Apr' : '04',
    'May' : '05',
    'Jun' : '06',
    'Jul' : '07',
    'Aug' : '08',
    'Sep' : '09',
    'Oct' : '10',
    'Nov' : '11',
    'Dec' : '12'
}

SQL datetime format to date only

if you are using SQL Server use convert

e.g. select convert(varchar(10), DeliveryDate, 103) as ShortDate

more information here: http://msdn.microsoft.com/en-us/library/aa226054(v=sql.80).aspx

Vue.js data-bind style backgroundImage not working

I tried @david answer, and it didn't fix my issue. after a lot of hassle, I made a method and return the image with style string.

HTML Code

<div v-for="slide in loadSliderImages" :key="slide.id">
    <div v-else :style="bannerBgImage(slide.banner)"></div>
</div>

Method

bannerBgImage(image){
    return 'background-image: url("' + image + '")';
},

PowerShell To Set Folder Permissions

Another example using PowerShell for set permissions (File / Directory) :

Verify permissions

Get-Acl "C:\file.txt" | fl *

Apply full permissions for everyone

$acl = Get-Acl "C:\file.txt"
$accessRule = New-Object System.Security.AccessControl.FileSystemAccessRule("everyone","FullControl","Allow")
$acl.SetAccessRule($accessRule)
$acl | Set-Acl "C:\file.txt"

Screenshots: enter image description here enter image description here

Hope this helps

How can I create a self-signed cert for localhost?

Since this question is tagged with IIS and I can't find a good answer on how to get a trusted certificate I will give my 2 cents about it:

First use the command from @AuriRahimzadeh in PowerShell as administrator:

New-SelfSignedCertificate -DnsName "localhost" -CertStoreLocation "cert:\LocalMachine\My"

This is good but the certificate is not trusted and will result in the following error. It is because it is not installed in Trusted Root Certification Authorities.

enter image description here

Solve this by starting mmc.exe.

Then go to:

File -> Add or Remove Snap-ins -> Certificates -> Add -> Computer account -> Local computer. Click Finish.

Expand the Personal folder and you will see your localhost certificate:

enter image description here

Copy the certificate into Trusted Root Certification Authorities - Certificates folder.

The final step is to open Internet Information Services (IIS) Manager or simply inetmgr.exe. From there go to your site, select Bindings... and Add... or Edit.... Set https and select your certificate from the drop down.

enter image description here

Your certificate is now trusted:

enter image description here

Fixed width buttons with Bootstrap

To do this you can come up with a width you feel is ok for both buttons and then create a custom class with the width and add it to your buttons like so:

CSS

.custom {
    width: 78px !important;
}

I can then use this class and add it to the buttons like so:

<p><button href="#" class="btn btn-primary custom">Save</button></p>
<p><button href="#" class="btn btn-success custom">Download</button></p>

Demo: http://jsfiddle.net/yNsxU/

You can take that custom class you create and place it inside your own stylesheet, which you load after the bootstrap stylesheet. We do this because any changes you place inside the bootstrap stylesheet might get accidentally lost when you update the framework, we also want your changes to take precedence over the default values.

Javascript change date into format of (dd/mm/yyyy)

This will ensure you get a two-digit day and month.

function formattedDate(d = new Date) {
  let month = String(d.getMonth() + 1);
  let day = String(d.getDate());
  const year = String(d.getFullYear());

  if (month.length < 2) month = '0' + month;
  if (day.length < 2) day = '0' + day;

  return `${day}/${month}/${year}`;
}

Or terser:

function formattedDate(d = new Date) {
  return [d.getDate(), d.getMonth()+1, d.getFullYear()]
      .map(n => n < 10 ? `0${n}` : `${n}`).join('/');
}

Plotting histograms from grouped data in a pandas DataFrame

I'm on a roll, just found an even simpler way to do it using the by keyword in the hist method:

df['N'].hist(by=df['Letter'])

That's a very handy little shortcut for quickly scanning your grouped data!

For future visitors, the product of this call is the following chart: enter image description here

Using IF..ELSE in UPDATE (SQL server 2005 and/or ACCESS 2007)

Yes you can use CASE

UPDATE table 
SET columnB = CASE fieldA 
        WHEN columnA=1 THEN 'x' 
        WHEN columnA=2 THEN 'y' 
        ELSE 'z' 
      END 
WHERE columnC = 1

How to set DialogFragment's width and height?

The dimension in outermost layout doesn't work in dialog. You can add a layout where set dimension below the outermost.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">

<LinearLayout
    android:layout_width="xxdp"
    android:layout_height="xxdp"
    android:orientation="vertical">

</LinearLayout>

Conda command not found

I had the same issue. I just closed and reopened the terminal, and it worked. That was because I installed anaconda with the terminal open.

How to set a header for a HTTP GET request, and trigger file download?

Try

html

<!-- placeholder , 
    `click` download , `.remove()` options ,
     at js callback , following js 
-->
<a>download</a>

js

        $(document).ready(function () {
            $.ajax({
                // `url` 
                url: '/echo/json/',
                type: "POST",
                dataType: 'json',
                // `file`, data-uri, base64
                data: {
                    json: JSON.stringify({
                        "file": "data:text/plain;base64,YWJj"
                    })
                },
                // `custom header`
                headers: {
                    "x-custom-header": 123
                },
                beforeSend: function (jqxhr) {
                    console.log(this.headers);
                    alert("custom headers" + JSON.stringify(this.headers));
                },
                success: function (data) {
                    // `file download`
                    $("a")
                        .attr({
                        "href": data.file,
                            "download": "file.txt"
                    })
                        .html($("a").attr("download"))
                        .get(0).click();
                    console.log(JSON.parse(JSON.stringify(data)));
                },
                error: function (jqxhr, textStatus, errorThrown) {
                  console.log(textStatus, errorThrown)
                }
            });
        });

jsfiddle http://jsfiddle.net/guest271314/SJYy3/

Uint8Array to string in Javascript

Do what @Sudhir said, and then to get a String out of the comma seperated list of numbers use:

for (var i=0; i<unitArr.byteLength; i++) {
            myString += String.fromCharCode(unitArr[i])
        }

This will give you the string you want, if it's still relevant

Revert to Eclipse default settings

Not even a single answer of the above let me able to get the original theme as I expected. I tried myself & got my default theme by changing the workspace. This led me to the original theme (same-to-same) that I used to saw when installing eclipse !

Assignment inside lambda expression in Python

Normal assignment (=) is not possible inside a lambda expression, although it is possible to perform various tricks with setattr and friends.

Solving your problem, however, is actually quite simple:

input = [Object(name=""), Object(name="fake_name"), Object(name="")]
output = filter(
    lambda o, _seen=set():
        not (not o and o in _seen or _seen.add(o)),
    input
    )

which will give you

[Object(Object(name=''), name='fake_name')]

As you can see, it's keeping the first blank instance instead of the last. If you need the last instead, reverse the list going in to filter, and reverse the list coming out of filter:

output = filter(
    lambda o, _seen=set():
        not (not o and o in _seen or _seen.add(o)),
    input[::-1]
    )[::-1]

which will give you

[Object(name='fake_name'), Object(name='')]

One thing to be aware of: in order for this to work with arbitrary objects, those objects must properly implement __eq__ and __hash__ as explained here.

Django - makemigrations - No changes detected

I've read many answers to this question often stating to simply run makemigrations in some other ways. But to me, the problem was in the Meta subclass of models.

I have an app config that says label = <app name> (in the apps.py file, beside models.py, views.py etc). If by any chance your meta class doesn't have the same label as the app label (for instance because you are splitting one too big app into multiple ones), no changes are detected (and no helpful error message whatsoever). So in my model class I have now:

class ModelClassName(models.Model):

    class Meta:
        app_label = '<app name>' # <-- this label was wrong before.

    field_name = models.FloatField()
    ...

Running Django 1.10 here.

Android get current Locale, not default

Android N (Api level 24) update (no warnings):

   Locale getCurrentLocale(Context context){
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N){
            return context.getResources().getConfiguration().getLocales().get(0);
        } else{
            //noinspection deprecation
            return context.getResources().getConfiguration().locale;
        }
    }

Output data from all columns in a dataframe in pandas

I know this is an old question, but I have just had a similar problem and I think what I did would work for you too.

I used the to_csv() method and wrote to stdout:

import sys

paramdata.to_csv(sys.stdout)

This should dump the whole dataframe whether it's nicely-printable or not, and you can use the to_csv parameters to configure column separators, whether the index is printed, etc.

Edit: It is now possible to use None as the target for .to_csv() with similar effect, which is arguably a lot nicer:

paramdata.to_csv(None)

Check if enum exists in Java

I don't know why anyone told you that catching runtime exceptions was bad.

Use valueOf and catching IllegalArgumentException is fine for converting/checking a string to an enum.

Android ListView selected item stay highlighted

I found the proper way. It's very simple. In resource describe following:

android:choiceMode="singleChoice"
android:listSelector="#666666"

(or you may specify a resource link instead of color value)

Programmatical:

listView.setSelector(Drawable selector);
listView.setSelector(int resourceId);
listView.setChoiceMode(int mode);

mode can be one of these: AbsListView.CHOICE_MODE_SINGLE, AbsListView.CHOICE_MODE_MULTIPLE, AbsListView.CHOICE_MODE_NONE (default)

(AbsListView is the abstract ancestor for the ListView class)

P.S. manipulations with onItemClick and changing view background are bankrupt, because a view itself is a temporary object. Hence you must not to track a view.

If our list is long enough, the views associated with scrolled out items will be removed from hierarchy, and will be recreated when those items will shown again (with cached display options, such as background). So, the view we have tracked is now not an actual view of the item, and changing its background does nothing to the actual item view. As a result we have multiple items selected.

Check/Uncheck checkbox with JavaScript

to check:

document.getElementById("id-of-checkbox").checked = true;

to uncheck:

document.getElementById("id-of-checkbox").checked = false;

Text not wrapping inside a div element

you can add this line: word-break:break-all; to your CSS-code

How do I jump out of a foreach loop in C#?

foreach (var item in listOfItems) {
  if (condition_is_met)
    // Any processing you may need to complete here...
    break; // return true; also works if you're looking to
           // completely exit this function.
}

Should do the trick. The break statement will just end the execution of the loop, while the return statement will obviously terminate the entire function. Judging from your question you may want to use the return true; statement.

Get all child views inside LinearLayout at once

Use getChildCount() and getChildAt(int index).

Example:

LinearLayout ll = …
final int childCount = ll.getChildCount();
for (int i = 0; i < childCount; i++) {
      View v = ll.getChildAt(i);
      // Do something with v.
      // …
}

What is the preferred syntax for initializing a dict: curly brace literals {} or the dict() function?

I almost always use curly-braces; however, in some cases where I'm writing tests, I do keyword packing/unpacking, and in these cases dict() is much more maintainable, as I don't need to change:

a=1,
b=2,

to:

'a': 1,
'b': 2,

It also helps in some circumstances where I think I might want to turn it into a namedtuple or class instance at a later time.

In the implementation itself, because of my obsession with optimisation, and when I don't see a particularly huge maintainability benefit, I'll always favour curly-braces.

In tests and the implementation, I would never use dict() if there is a chance that the keys added then, or in the future, would either:

  • Not always be a string
  • Not only contain digits, ASCII letters and underscores
  • Start with an integer (dict(1foo=2) raises a SyntaxError)

Java: how to import a jar file from command line

If you're running a jar file with java -jar, the -classpath argument is ignored. You need to set the classpath in the manifest file of your jar, like so:

Class-Path: jar1-name jar2-name directory-name/jar3-name

See the Java tutorials: Adding Classes to the JAR File's Classpath.

Edit: I see you already tried setting the class path in the manifest, but are you sure you used the correct syntax? If you skip the ':' after "Class-Path" like you showed, it would not work.

Converting datetime.date to UTC timestamp in Python

the question is a little confused. timestamps are not UTC - they're a Unix thing. the date might be UTC? assuming it is, and if you're using Python 3.2+, simple-date makes this trivial:

>>> SimpleDate(date(2011,1,1), tz='utc').timestamp
1293840000.0

if you actually have the year, month and day you don't need to create the date:

>>> SimpleDate(2011,1,1, tz='utc').timestamp
1293840000.0

and if the date is in some other timezone (this matters because we're assuming midnight without an associated time):

>>> SimpleDate(date(2011,1,1), tz='America/New_York').timestamp
1293858000.0

[the idea behind simple-date is to collect all python's date and time stuff in one consistent class, so you can do any conversion. so, for example, it will also go the other way:

>>> SimpleDate(1293858000, tz='utc').date
datetime.date(2011, 1, 1)

]

HttpClient - A task was cancelled?

Another reason can be that if you are running the service (API) and put a breakpoint in the service (and your code is stuck at some breakpoint (e.g Visual Studio solution is showing Debugging instead of Running)). and then hitting the API from the client code. So if the service code a paused on some breakpoint, you just hit F5 in VS.

Properly Handling Errors in VBA (Excel)

You've got one truly marvelous answer from ray023, but your comment that it's probably overkill is apt. For a "lighter" version....

Block 1 is, IMHO, bad practice. As already pointed out by osknows, mixing error-handling with normal-path code is Not Good. For one thing, if a new error is thrown while there's an Error condition in effect you will not get an opportunity to handle it (unless you're calling from a routine that also has an error handler, where the execution will "bubble up").

Block 2 looks like an imitation of a Try/Catch block. It should be okay, but it's not The VBA Way. Block 3 is a variation on Block 2.

Block 4 is a bare-bones version of The VBA Way. I would strongly advise using it, or something like it, because it's what any other VBA programmer inherting the code will expect. Let me present a small expansion, though:

Private Sub DoSomething()
On Error GoTo ErrHandler

'Dim as required

'functional code that might throw errors

ExitSub:
    'any always-execute (cleanup?) code goes here -- analagous to a Finally block.
    'don't forget to do this -- you don't want to fall into error handling when there's no error
    Exit Sub

ErrHandler:
    'can Select Case on Err.Number if there are any you want to handle specially

    'display to user
    MsgBox "Something's wrong: " & vbCrLf & Err.Description

    'or use a central DisplayErr routine, written Public in a Module
    DisplayErr Err.Number, Err.Description

    Resume ExitSub
    Resume
End Sub

Note that second Resume. This is a trick I learned recently: It will never execute in normal processing, since the Resume <label> statement will send the execution elsewhere. It can be a godsend for debugging, though. When you get an error notification, choose Debug (or press Ctl-Break, then choose Debug when you get the "Execution was interrupted" message). The next (highlighted) statement will be either the MsgBox or the following statement. Use "Set Next Statement" (Ctl-F9) to highlight the bare Resume, then press F8. This will show you exactly where the error was thrown.

As to your objection to this format "jumping around", A) it's what VBA programmers expect, as stated previously, & B) your routines should be short enough that it's not far to jump.

How do I 'svn add' all unversioned files to SVN?

Since this post is tagged Windows, I thought I would work out a solution for Windows. I wanted to automate the process, and I made a bat file. I resisted making a console.exe in C#.

I wanted to add any files or folders which are not added in my repository when I begin the commit process.

The problem with many of the answers is they will list unversioned files which should be ignored as per my ignore list in TortoiseSVN.

Here is my hook setting and batch file which does that

Tortoise Hook Script:

"start_commit_hook".
(where I checkout) working copy path = C:\Projects
command line: C:\windows\system32\cmd.exe /c C:\Tools\SVN\svnadd.bat
(X) Wait for the script to finish
(X) (Optional) Hide script while running
(X) Always execute the script

svnadd.bat

@echo off

rem Iterates each line result from the command which lists files/folders
rem     not added to source control while respecting the ignore list.
FOR /F "delims==" %%G IN ('svn status ^| findstr "^?"') DO call :DoSVNAdd "%%G"
goto end

:DoSVNAdd
set addPath=%1
rem Remove line prefix formatting from svn status command output as well as
rem    quotes from the G call (as required for long folder names). Then
rem    place quotes back around the path for the SVN add call.
set addPath="%addPath:~9,-1%"
svn add %addPath%

:end

How to use "svn export" command to get a single file from the repository?

I know the OP was asking about doing the export from the command line, but just in case this is helpful to anyone else out there...

You could just let Eclipse (plus one of the plugins discussed here) do the work for you.

Obviously, downloading Eclipse just for doing a single export is overkill, but if you are already using it for development, you can also do an svn export simply from your IDE's context menu when browsing an SVN repository.

Advantages:

  • easier for those not so familiar with using SVN at the command-line level (but you can learn about what happens at the command-line level by looking at the SVN console with a range of commands)
  • you'd already have your SVN details set up and wouldn't have to worry about authenticating, etc.
  • you don't have to worry about mistyping the URL, or remembering the order of parameters
  • you can specify in a dialog which directory you'd like to export to
  • you can specify in a dialog whether you'd like to export from TRUNK/HEAD or use a specific revision

What's the difference between Thread start() and Runnable run()

If you directly call run() method, you are not using multi-threading feature since run() method is executed as part of caller thread.

If you call start() method on Thread, the Java Virtual Machine will call run() method and two threads will run concurrently - Current Thread (main() in your example) and Other Thread (Runnable r1 in your example).

Have a look at source code of start() method in Thread class

 /**
     * Causes this thread to begin execution; the Java Virtual Machine
     * calls the <code>run</code> method of this thread.
     * <p>
     * The result is that two threads are running concurrently: the
     * current thread (which returns from the call to the
     * <code>start</code> method) and the other thread (which executes its
     * <code>run</code> method).
     * <p>
     * It is never legal to start a thread more than once.
     * In particular, a thread may not be restarted once it has completed
     * execution.
     *
     * @exception  IllegalThreadStateException  if the thread was already
     *               started.
     * @see        #run()
     * @see        #stop()
     */
    public synchronized void start() {
        /**
         * This method is not invoked for the main method thread or "system"
         * group threads created/set up by the VM. Any new functionality added
         * to this method in the future may have to also be added to the VM.
         *
         * A zero status value corresponds to state "NEW".
         */
        if (threadStatus != 0)
            throw new IllegalThreadStateException();
        group.add(this);
        start0();
        if (stopBeforeStart) {
            stop0(throwableFromStop);
        }
    }

    private native void start0();

In above code, you can't see invocation to run() method.

private native void start0() is responsible for calling run() method. JVM executes this native method.

How to call a method in MainActivity from another class?

Simply, You can make this method static as below:

public static void startChronometer(){
    mChronometer.start();
    showElapsedTime();
} 

you can call this function in other class as below:

MainActivity.startChronometer();

Roblox Admin Command Script

for i=1,#target do
    game.Players.target[i].Character:BreakJoints()
end

Is incorrect, if "target" contains "FakeNameHereSoNoStalkers" then the run code would be:

game.Players.target.1.Character:BreakJoints()

Which is completely incorrect.


c = game.Players:GetChildren()

Never use "Players:GetChildren()", it is not guaranteed to return only players.

Instead use:

c = Game.Players:GetPlayers()

if msg:lower()=="me" then
    table.insert(people, source)
    return people

Here you add the player's name in the list "people", where you in the other places adds the player object.


Fixed code:

local Admins = {"FakeNameHereSoNoStalkers"}

function Kill(Players)
    for i,Player in ipairs(Players) do
        if Player.Character then
            Player.Character:BreakJoints()
        end
    end
end

function IsAdmin(Player)
    for i,AdminName in ipairs(Admins) do
        if Player.Name:lower() == AdminName:lower() then return true end
    end
    return false
end

function GetPlayers(Player,Msg)
    local Targets = {}
    local Players = Game.Players:GetPlayers()

    if Msg:lower() == "me" then
        Targets = { Player }
    elseif Msg:lower() == "all" then
        Targets = Players
    elseif Msg:lower() == "others" then
        for i,Plr in ipairs(Players) do
            if Plr ~= Player then
                table.insert(Targets,Plr)
            end
        end
    else
        for i,Plr in ipairs(Players) do
            if Plr.Name:lower():sub(1,Msg:len()) == Msg then
                table.insert(Targets,Plr)
            end
        end
    end
    return Targets
end

Game.Players.PlayerAdded:connect(function(Player)
    if IsAdmin(Player) then
        Player.Chatted:connect(function(Msg)
            if Msg:lower():sub(1,6) == ":kill " then
                Kill(GetPlayers(Player,Msg:sub(7)))
            end
        end)
    end
end)

PHP CURL DELETE request

My own class request with wsse authentication

class Request {

    protected $_url;
    protected $_username;
    protected $_apiKey;

    public function __construct($url, $username, $apiUserKey) {
        $this->_url = $url;     
        $this->_username = $username;
        $this->_apiKey = $apiUserKey;
    }

    public function getHeader() {
        $nonce = uniqid();
        $created = date('c');
        $digest = base64_encode(sha1(base64_decode($nonce) . $created . $this->_apiKey, true));

        $wsseHeader = "Authorization: WSSE profile=\"UsernameToken\"\n";
        $wsseHeader .= sprintf(
            'X-WSSE: UsernameToken Username="%s", PasswordDigest="%s", Nonce="%s", Created="%s"', $this->_username, $digest, $nonce, $created
        );

        return $wsseHeader;
    }

    public function curl_req($path, $verb=NULL, $data=array()) {                    

        $wsseHeader[] = "Accept: application/vnd.api+json";
        $wsseHeader[] = $this->getHeader();

        $options = array(
            CURLOPT_URL => $this->_url . $path,
            CURLOPT_HTTPHEADER => $wsseHeader,
            CURLOPT_RETURNTRANSFER => true, 
            CURLOPT_HEADER => false             
        );                  

        if( !empty($data) ) {
            $options += array(
                CURLOPT_POSTFIELDS => $data,
                CURLOPT_SAFE_UPLOAD => true
            );                          
        }

        if( isset($verb) ) {
            $options += array(CURLOPT_CUSTOMREQUEST => $verb);                          
        }

        $ch = curl_init();
        curl_setopt_array($ch, $options);
        $result = curl_exec($ch);                   

        if(false === $result ) {
            echo curl_error($ch);
        }
        curl_close($ch);

        return $result; 
    }
}

Can I rollback a transaction I've already committed? (data loss)

No, you can't undo, rollback or reverse a commit.

STOP THE DATABASE!

(Note: if you deleted the data directory off the filesystem, do NOT stop the database. The following advice applies to an accidental commit of a DELETE or similar, not an rm -rf /data/directory scenario).

If this data was important, STOP YOUR DATABASE NOW and do not restart it. Use pg_ctl stop -m immediate so that no checkpoint is run on shutdown.

You cannot roll back a transaction once it has commited. You will need to restore the data from backups, or use point-in-time recovery, which must have been set up before the accident happened.

If you didn't have any PITR / WAL archiving set up and don't have backups, you're in real trouble.

Urgent mitigation

Once your database is stopped, you should make a file system level copy of the whole data directory - the folder that contains base, pg_clog, etc. Copy all of it to a new location. Do not do anything to the copy in the new location, it is your only hope of recovering your data if you do not have backups. Make another copy on some removable storage if you can, and then unplug that storage from the computer. Remember, you need absolutely every part of the data directory, including pg_xlog etc. No part is unimportant.

Exactly how to make the copy depends on which operating system you're running. Where the data dir is depends on which OS you're running and how you installed PostgreSQL.

Ways some data could've survived

If you stop your DB quickly enough you might have a hope of recovering some data from the tables. That's because PostgreSQL uses multi-version concurrency control (MVCC) to manage concurrent access to its storage. Sometimes it will write new versions of the rows you update to the table, leaving the old ones in place but marked as "deleted". After a while autovaccum comes along and marks the rows as free space, so they can be overwritten by a later INSERT or UPDATE. Thus, the old versions of the UPDATEd rows might still be lying around, present but inaccessible.

Additionally, Pg writes in two phases. First data is written to the write-ahead log (WAL). Only once it's been written to the WAL and hit disk, it's then copied to the "heap" (the main tables), possibly overwriting old data that was there. The WAL content is copied to the main heap by the bgwriter and by periodic checkpoints. By default checkpoints happen every 5 minutes. If you manage to stop the database before a checkpoint has happened and stopped it by hard-killing it, pulling the plug on the machine, or using pg_ctl in immediate mode you might've captured the data from before the checkpoint happened, so your old data is more likely to still be in the heap.

Now that you have made a complete file-system-level copy of the data dir you can start your database back up if you really need to; the data will still be gone, but you've done what you can to give yourself some hope of maybe recovering it. Given the choice I'd probably keep the DB shut down just to be safe.

Recovery

You may now need to hire an expert in PostgreSQL's innards to assist you in a data recovery attempt. Be prepared to pay a professional for their time, possibly quite a bit of time.

I posted about this on the Pg mailing list, and ?????? ?????? linked to depesz's post on pg_dirtyread, which looks like just what you want, though it doesn't recover TOASTed data so it's of limited utility. Give it a try, if you're lucky it might work.

See: pg_dirtyread on GitHub.

I've removed what I'd written in this section as it's obsoleted by that tool.

See also PostgreSQL row storage fundamentals

Prevention

See my blog entry Preventing PostgreSQL database corruption.


On a semi-related side-note, if you were using two phase commit you could ROLLBACK PREPARED for a transction that was prepared for commit but not fully commited. That's about the closest you get to rolling back an already-committed transaction, and does not apply to your situation.

How to display image with JavaScript?

You could make use of the Javascript DOM API. In particular, look at the createElement() method.

You could create a re-usable function that will create an image like so...

function show_image(src, width, height, alt) {
    var img = document.createElement("img");
    img.src = src;
    img.width = width;
    img.height = height;
    img.alt = alt;

    // This next line will just add it to the <body> tag
    document.body.appendChild(img);
}

Then you could use it like this...

<button onclick=
    "show_image('http://google.com/images/logo.gif', 
                 276, 
                 110, 
                 'Google Logo');">Add Google Logo</button> 

See a working example on jsFiddle: http://jsfiddle.net/Bc6Et/

m2eclipse not finding maven dependencies, artifacts not found

One of the reason I found was why it doesn't find a jar from repository might be because the .pom file for that particular jar might be missing or corrupt. Just correct it and try to load from local repository.

postgresql COUNT(DISTINCT ...) very slow

I was also searching same answer, because at some point of time I needed total_count with distinct values along with limit/offset.

Because it's little tricky to do- To get total count with distinct values along with limit/offset. Usually it's hard to get total count with limit/offset. Finally I got the way to do -

SELECT DISTINCT COUNT(*) OVER() as total_count, * FROM table_name limit 2 offset 0;

Query performance is also high.

What is the difference between compare() and compareTo()?

Similarities:
Both are custom ways to compare two objects.
Both return an int describing the relationship between two objects.

Differences: The method compare() is a method that you are obligated to implement if you implement the Comparator interface. It allows you to pass two objects into the method and it returns an int describing their relationship.

Comparator comp = new MyComparator();
int result = comp.compare(object1, object2);

The method compareTo() is a method that you are obligated to implement if you implement the Comparable interface. It allows an object to be compared to objects of similar type.

String s = "hi";
int result = s.compareTo("bye");

Summary:
Basically they are two different ways to compare things.

CREATE FILE encountered operating system error 5(failed to retrieve text for this error. Reason: 15105)

Right Click on File mdf and ldf properties -> security ->full permission

"Press Any Key to Continue" function in C

You don't say what system you're using, but as you already have some answers that may or may not work for Windows, I'll answer for POSIX systems.

In POSIX, keyboard input comes through something called a terminal interface, which by default buffers lines of input until Return/Enter is hit, so as to deal properly with backspace. You can change that with the tcsetattr call:

#include <termios.h>

struct termios info;
tcgetattr(0, &info);          /* get current terminal attirbutes; 0 is the file descriptor for stdin */
info.c_lflag &= ~ICANON;      /* disable canonical mode */
info.c_cc[VMIN] = 1;          /* wait until at least one keystroke available */
info.c_cc[VTIME] = 0;         /* no timeout */
tcsetattr(0, TCSANOW, &info); /* set immediately */

Now when you read from stdin (with getchar(), or any other way), it will return characters immediately, without waiting for a Return/Enter. In addition, backspace will no longer 'work' -- instead of erasing the last character, you'll read an actual backspace character in the input.

Also, you'll want to make sure to restore canonical mode before your program exits, or the non-canonical handling may cause odd effects with your shell or whoever invoked your program.

Python 3 TypeError: must be str, not bytes with sys.stdout.write()

Python 3 handles strings a bit different. Originally there was just one type for strings: str. When unicode gained traction in the '90s the new unicode type was added to handle Unicode without breaking pre-existing code1. This is effectively the same as str but with multibyte support.

In Python 3 there are two different types:

  • The bytes type. This is just a sequence of bytes, Python doesn't know anything about how to interpret this as characters.
  • The str type. This is also a sequence of bytes, but Python knows how to interpret those bytes as characters.
  • The separate unicode type was dropped. str now supports unicode.

In Python 2 implicitly assuming an encoding could cause a lot of problems; you could end up using the wrong encoding, or the data may not have an encoding at all (e.g. it’s a PNG image).
Explicitly telling Python which encoding to use (or explicitly telling it to guess) is often a lot better and much more in line with the "Python philosophy" of "explicit is better than implicit".

This change is incompatible with Python 2 as many return values have changed, leading to subtle problems like this one; it's probably the main reason why Python 3 adoption has been so slow. Since Python doesn't have static typing2 it's impossible to change this automatically with a script (such as the bundled 2to3).

  • You can convert str to bytes with bytes('h€llo', 'utf-8'); this should produce b'H\xe2\x82\xacllo'. Note how one character was converted to three bytes.
  • You can convert bytes to str with b'H\xe2\x82\xacllo'.decode('utf-8').

Of course, UTF-8 may not be the correct character set in your case, so be sure to use the correct one.

In your specific piece of code, nextline is of type bytes, not str, reading stdout and stdin from subprocess changed in Python 3 from str to bytes. This is because Python can't be sure which encoding this uses. It probably uses the same as sys.stdin.encoding (the encoding of your system), but it can't be sure.

You need to replace:

sys.stdout.write(nextline)

with:

sys.stdout.write(nextline.decode('utf-8'))

or maybe:

sys.stdout.write(nextline.decode(sys.stdout.encoding))

You will also need to modify if nextline == '' to if nextline == b'' since:

>>> '' == b''
False

Also see the Python 3 ChangeLog, PEP 358, and PEP 3112.


1 There are some neat tricks you can do with ASCII that you can't do with multibyte character sets; the most famous example is the "xor with space to switch case" (e.g. chr(ord('a') ^ ord(' ')) == 'A') and "set 6th bit to make a control character" (e.g. ord('\t') + ord('@') == ord('I')). ASCII was designed in a time when manipulating individual bits was an operation with a non-negligible performance impact.

2 Yes, you can use function annotations, but it's a comparatively new feature and little used.

How to force open links in Chrome not download them?

Great question.

It can be achieved via an extension:

How to use IntelliJ IDEA to find all unused code?

In latest IntelliJ versions, you should run it from Analyze->Run Inspection By Name:

enter image description here

Than, pick Unused declaration:

enter image description here

And finally, uncheck the Include test sources:

enter image description here

Convert List into Comma-Separated String

If you have a collection of ints:

List<int> customerIds= new List<int>() { 1,2,3,3,4,5,6,7,8,9 };  

You can use string.Join to get a string:

var result = String.Join(",", customerIds);

Enjoy!

What are the differences among grep, awk & sed?

I just want to mention a thing, there are many tools can do text processing, e.g. sort, cut, split, join, paste, comm, uniq, column, rev, tac, tr, nl, pr, head, tail.....

they are very handy but you have to learn their options etc.

A lazy way (not the best way) to learn text processing might be: only learn grep , sed and awk. with this three tools, you can solve almost 99% of text processing problems and don't need to memorize above different cmds and options. :)

AND, if you 've learned and used the three, you knew the difference. Actually, the difference here means which tool is good at solving what kind of problem.

a more lazy way might be learning a script language (python, perl or ruby) and do every text processing with it.

How to perform element-wise multiplication of two lists?

To maintain the list type, and do it in one line (after importing numpy as np, of course):

list(np.array([1,2,3,4]) * np.array([2,3,4,5]))

or

list(np.array(a) * np.array(b))

Line break in SSRS expression

You Can Use This One

="Line 1" & "<br>" & "Line 2"

XPath: How to select elements based on their value?

The condition below:

//Element[@attribute1="abc" and @attribute2="xyz" and Data]

checks for the existence of the element Data within Element and not for element value Data.

Instead you can use

//Element[@attribute1="abc" and @attribute2="xyz" and text()="Data"]

how to play video from url

Check whether your phone supports the video format or not.Even I had the problem when playing a 3gp file but it played a mp4 file perfectly.

What could cause java.lang.reflect.InvocationTargetException?

I had a java.lang.reflect.InvocationTargetException error from a statement calling a logger object in an external class inside a try / catch block in my class.

Stepping through the code in the Eclipse debugger & hovering the mouse over the logger statement I saw the logger object was null (some external constants needed to be instantiated at the very top of my class).

How do I convert Long to byte[] and back in java

 public static long bytesToLong(byte[] bytes) {
        if (bytes.length > 8) {
            throw new IllegalMethodParameterException("byte should not be more than 8 bytes");

        }
        long r = 0;
        for (int i = 0; i < bytes.length; i++) {
            r = r << 8;
            r += bytes[i];
        }

        return r;
    }



public static byte[] longToBytes(long l) {
        ArrayList<Byte> bytes = new ArrayList<Byte>();
        while (l != 0) {
            bytes.add((byte) (l % (0xff + 1)));
            l = l >> 8;
        }
        byte[] bytesp = new byte[bytes.size()];
        for (int i = bytes.size() - 1, j = 0; i >= 0; i--, j++) {
            bytesp[j] = bytes.get(i);
        }
        return bytesp;
    }

TypeError: expected string or buffer

lines is a list. re.findall() doesn't take lists.

>>> import re
>>> f = open('README.md', 'r')
>>> lines = f.readlines()
>>> match = re.findall('[A-Z]+', lines)
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/usr/lib/python2.7/re.py", line 177, in findall
    return _compile(pattern, flags).findall(string)
TypeError: expected string or buffer
>>> type(lines)
<type 'list'>

From help(file.readlines). I.e. readlines() is for loops/iterating:

readlines(...)
    readlines([size]) -> list of strings, each a line from the file.

To find all uppercase characters in your file:

>>> import re
>>> re.findall('[A-Z]+', open('README.md', 'r').read())
['S', 'E', 'A', 'P', 'S', 'I', 'R', 'C', 'I', 'A', 'P', 'O', 'G', 'P', 'P', 'T', 'V', 'W', 'V', 'D', 'A', 'L', 'U', 'O', 'I', 'L', 'P', 'A', 'D', 'V', 'S', 'M', 'S', 'L', 'I', 'D', 'V', 'S', 'M', 'A', 'P', 'T', 'P', 'Y', 'C', 'M', 'V', 'Y', 'C', 'M', 'R', 'R', 'B', 'P', 'M', 'L', 'F', 'D', 'W', 'V', 'C', 'X', 'S']

Iterating over and deleting from Hashtable in Java

You can use a temporary deletion list:

List<String> keyList = new ArrayList<String>;

for(Map.Entry<String,String> entry : hashTable){
  if(entry.getValue().equals("delete")) // replace with your own check
    keyList.add(entry.getKey());
}

for(String key : keyList){
  hashTable.remove(key);
}

You can find more information about Hashtable methods in the Java API

Convert INT to FLOAT in SQL

In oracle db there is a trick for casting int to float (I suppose, it should also work in mysql):

select myintfield + 0.0 as myfloatfield from mytable

While @Heximal's answer works, I don't personally recommend it.

This is because it uses implicit casting. Although you didn't type CAST, either the SUM() or the 0.0 need to be cast to be the same data-types, before the + can happen. In this case the order of precedence is in your favour, and you get a float on both sides, and a float as a result of the +. But SUM(aFloatField) + 0 does not yield an INT, because the 0 is being implicitly cast to a FLOAT.

I find that in most programming cases, it is much preferable to be explicit. Don't leave things to chance, confusion, or interpretation.

If you want to be explicit, I would use the following.

CAST(SUM(sl.parts) AS FLOAT) * cp.price
-- using MySQL CAST FLOAT  requires 8.0

I won't discuss whether NUMERIC or FLOAT *(fixed point, instead of floating point)* is more appropriate, when it comes to rounding errors, etc. I'll just let you google that if you need to, but FLOAT is so massively misused that there is a lot to read about the subject already out there.

You can try the following to see what happens...

CAST(SUM(sl.parts) AS NUMERIC(10,4)) * CAST(cp.price AS NUMERIC(10,4))

Convert Datetime column from UTC to local time in select statement

I have code to perform UTC to Local and Local to UTC times which allows conversion using code like this

DECLARE @usersTimezone VARCHAR(32)='Europe/London'
DECLARE @utcDT DATETIME=GetUTCDate()
DECLARE @userDT DATETIME=[dbo].[funcUTCtoLocal](@utcDT, @usersTimezone)

and

DECLARE @usersTimezone VARCHAR(32)='Europe/London'
DECLARE @userDT DATETIME=GetDate()
DECLARE @utcDT DATETIME=[dbo].[funcLocaltoUTC](@userDT, @usersTimezone)

The functions can support all or a subset of timezones in the IANA/TZDB as provided by NodaTime - see the full list at https://nodatime.org/TimeZones

Be aware that my use case means I only need a 'current' window, allowing the conversion of times within the range of about +/- 5 years from now. This means that the method I've used probably isn't suitable for you if you need a very wide period of time, due to the way it generates code for each timezone interval in a given date range.

The project is on GitHub: https://github.com/elliveny/SQLServerTimeConversion

This generates SQL function code as per this example

Could not load file or assembly 'System.Web.WebPages.Razor, Version=2.0.0.0

I first tried Mohammed Emad's answer - no joy. Then I tried

git clean -x -d -f

which brought me to a new "Roslyn" error which I was able to fix by manually editing my .csproj.

Interestingly, after I'd read down a bit further down the page on the Roslyn question, I found another suggestion with even more votes (Update-Package Microsoft.CodeDom.Providers.DotNetCompilerPlatform -r). Thinking I'd rather implement that than manually edit .csproj, I backed out my .csproj changes, only to find my solution was still working.

So after all that, I'm wondering if Mohammed's answer (on this page) would have done the trick, had I simply done the git clean first.

How do I plot only a table in Matplotlib?

If you just wanted to change the example and put the table at the top, then loc='top' in the table declaration is what you need,

the_table = ax.table(cellText=cell_text,
                      rowLabels=rows,
                      rowColours=colors,
                      colLabels=columns,
                      loc='top')

Then adjusting the plot with,

plt.subplots_adjust(left=0.2, top=0.8)

A more flexible option is to put the table in its own axis using subplots,

import numpy as np
import matplotlib.pyplot as plt


fig, axs =plt.subplots(2,1)
clust_data = np.random.random((10,3))
collabel=("col 1", "col 2", "col 3")
axs[0].axis('tight')
axs[0].axis('off')
the_table = axs[0].table(cellText=clust_data,colLabels=collabel,loc='center')

axs[1].plot(clust_data[:,0],clust_data[:,1])
plt.show()

which looks like this,

enter image description here

You are then free to adjust the locations of the axis as required.

Mocking a class: Mock() or patch()?

Key points which explain difference and provide guidance upon working with unittest.mock

  1. Use Mock if you want to replace some interface elements(passing args) of the object under test
  2. Use patch if you want to replace internal call to some objects and imported modules of the object under test
  3. Always provide spec from the object you are mocking
    • With patch you can always provide autospec
    • With Mock you can provide spec
    • Instead of Mock, you can use create_autospec, which intended to create Mock objects with specification.

In the question above the right answer would be to use Mock, or to be more precise create_autospec (because it will add spec to the mock methods of the class you are mocking), the defined spec on the mock will be helpful in case of an attempt to call method of the class which doesn't exists ( regardless signature), please see some

from unittest import TestCase
from unittest.mock import Mock, create_autospec, patch


class MyClass:
    
    @staticmethod
    def method(foo, bar):
        print(foo)


def something(some_class: MyClass):
    arg = 1
    # Would fail becuase of wrong parameters passed to methd.
    return some_class.method(arg)


def second(some_class: MyClass):
    arg = 1
    return some_class.unexisted_method(arg)


class TestSomethingTestCase(TestCase):
    def test_something_with_autospec(self):
        mock = create_autospec(MyClass)
        mock.method.return_value = True
        # Fails because of signature misuse.
        result = something(mock)
        self.assertTrue(result)
        self.assertTrue(mock.method.called)
    
    def test_something(self):
        mock = Mock()  # Note that Mock(spec=MyClass) will also pass, because signatures of mock don't have spec.
        mock.method.return_value = True
        
        result = something(mock)
        
        self.assertTrue(result)
        self.assertTrue(mock.method.called)
        
    def test_second_with_patch_autospec(self):
        with patch(f'{__name__}.MyClass', autospec=True) as mock:
            # Fails because of signature misuse.
            result = second(mock)
        self.assertTrue(result)
        self.assertTrue(mock.unexisted_method.called)


class TestSecondTestCase(TestCase):
    def test_second_with_autospec(self):
        mock = Mock(spec=MyClass)
        # Fails because of signature misuse.
        result = second(mock)
        self.assertTrue(result)
        self.assertTrue(mock.unexisted_method.called)
    
    def test_second_with_patch_autospec(self):
        with patch(f'{__name__}.MyClass', autospec=True) as mock:
            # Fails because of signature misuse.
            result = second(mock)
        self.assertTrue(result)
        self.assertTrue(mock.unexisted_method.called)
    
    def test_second(self):
        mock = Mock()
        mock.unexisted_method.return_value = True
        
        result = second(mock)
        
        self.assertTrue(result)
        self.assertTrue(mock.unexisted_method.called)

The test cases with defined spec used fail because methods called from something and second functions aren't complaint with MyClass, which means - they catch bugs, whereas default Mock will display.

As a side note there is one more option: use patch.object to mock just the class method which is called with.

The good use cases for patch would be the case when the class is used as inner part of function:

def something():
    arg = 1
    return MyClass.method(arg)

Then you will want to use patch as a decorator to mock the MyClass.

Difference between socket and websocket?

Websockets use sockets in their implementation. Websockets are based on a standard protocol (now in final call, but not yet final) that defines a connection "handshake" and message "frame." The two sides go through the handshake procedure to mutually accept a connection and then use the standard message format ("frame") to pass messages back and forth.

I'm developing a framework that will allow you to communicate directly machine to machine with installed software. It might suit your purpose. You can follow my blog if you wish: http://highlevellogic.blogspot.com/2011/09/websocket-server-demonstration_26.html

Loading a .json file into c# program

Another good way to serialize json into c# is below:

RootObject ro = new RootObject();
     try
    {

        StreamReader sr = new StreamReader(FileLoc);
        string jsonString = sr.ReadToEnd();
        JavaScriptSerializer ser = new JavaScriptSerializer();
        ro = ser.Deserialize<RootObject>(jsonString);


   }

you need to add a reference to system.web.extensions in .net 4.0 this is in program files (x86) > reference assemblies> framework> system.web.extensions.dll and you need to be sure you're using just regular 4.0 framework not 4.0 client

Sorting Python list based on the length of the string

I can do it using below two methods, using function

def lensort(x):
    list1 = []
    for i in x:
        list1.append([len(i),i])
    return sorted(list1)

lista = ['a', 'bb', 'ccc', 'dddd']
a=lensort(lista)
print([l[1] for l in a])

In one Liner using Lambda, as below, a already answered above.

 lista = ['a', 'bb', 'ccc', 'dddd']
 lista.sort(key = lambda x:len(x))
 print(lista)

Use C# HttpWebRequest to send json to web service

First of all you missed ScriptService attribute to add in webservice.

[ScriptService]

After then try following method to call webservice via JSON.

        var webAddr = "http://Domain/VBRService.asmx/callJson";
        var httpWebRequest = (HttpWebRequest)WebRequest.Create(webAddr);
        httpWebRequest.ContentType = "application/json; charset=utf-8";
        httpWebRequest.Method = "POST";            

        using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
        {
            string json = "{\"x\":\"true\"}";

            streamWriter.Write(json);
            streamWriter.Flush();
        }

        var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
        using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
        {
            var result = streamReader.ReadToEnd();
            return result;
        }

Advantage of switch over if-else statement

I would say use SWITCH. This way you only have to implement differing outcomes. Your ten identical cases can use the default. Should one change all you need to is explicitly implement the change, no need to edit the default. It's also far easier to add or remove cases from a SWITCH than to edit IF and ELSEIF.

switch(numerror){
    ERROR_20 : { fire_special_event(); } break;
    default : { null; } break;
}

Maybe even test your condition (in this case numerror) against a list of possibilities, an array perhaps so your SWITCH isn't even used unless there definately will be an outcome.

What is a Sticky Broadcast?

The value of a sticky broadcast is the value that was last broadcast and is currently held in the sticky cache. This is not the value of a broadcast that was received right now. I suppose you can say it is like a browser cookie that you can access at any time. The sticky broadcast is now deprecated, per the docs for sticky broadcast methods (e.g.):

This method was deprecated in API level 21. Sticky broadcasts should not be used. They provide no security (anyone can access them), no protection (anyone can modify them), and many other problems. The recommended pattern is to use a non-sticky broadcast to report that something has changed, with another mechanism for apps to retrieve the current value whenever desired.

JavaScript to scroll long page to DIV

<a href="#myAnchorALongWayDownThePage">Click here to scroll</a>

<A name='myAnchorALongWayDownThePage"></a>

No fancy scrolling but it should take you there.

add string to String array

you would have to write down some method to create a temporary array and then copy it like

public String[] increaseArray(String[] theArray, int increaseBy)  
{  
    int i = theArray.length;  
    int n = ++i;  
    String[] newArray = new String[n];  
    for(int cnt=0;cnt<theArray.length;cnt++)
    {  
        newArray[cnt] = theArray[cnt];  
    }  
    return newArray;  
}  

or The ArrayList would be helpful to resolve your problem.

Enter triggers button click

I would do it like the following: In the handler for the onclick event of the button (not submit) check the event object's keycode. If it is "enter" I would return false.

How to truncate a foreign key constrained table?

You cannot TRUNCATE a table that has FK constraints applied on it (TRUNCATE is not the same as DELETE).

To work around this, use either of these solutions. Both present risks of damaging the data integrity.

Option 1:

  1. Remove constraints
  2. Perform TRUNCATE
  3. Delete manually the rows that now have references to nowhere
  4. Create constraints

Option 2: suggested by user447951 in their answer

SET FOREIGN_KEY_CHECKS = 0; 
TRUNCATE table $table_name; 
SET FOREIGN_KEY_CHECKS = 1;

How to read keyboard-input?

Non-blocking, multi-threaded example:

As blocking on keyboard input (since the input() function blocks) is frequently not what we want to do (we'd frequently like to keep doing other stuff), here's a very-stripped-down multi-threaded example to demonstrate how to keep running your main application while still reading in keyboard inputs whenever they arrive.

This works by creating one thread to run in the background, continually calling input() and then passing any data it receives to a queue.

In this way, your main thread is left to do anything it wants, receiving the keyboard input data from the first thread whenever there is something in the queue.

1. Bare Python 3 code example (no comments):

import threading
import queue
import time

def read_kbd_input(inputQueue):
    print('Ready for keyboard input:')
    while (True):
        input_str = input()
        inputQueue.put(input_str)

def main():
    EXIT_COMMAND = "exit"
    inputQueue = queue.Queue()

    inputThread = threading.Thread(target=read_kbd_input, args=(inputQueue,), daemon=True)
    inputThread.start()

    while (True):
        if (inputQueue.qsize() > 0):
            input_str = inputQueue.get()
            print("input_str = {}".format(input_str))

            if (input_str == EXIT_COMMAND):
                print("Exiting serial terminal.")
                break
            
            # Insert your code here to do whatever you want with the input_str.

        # The rest of your program goes here.

        time.sleep(0.01) 
    print("End.")

if (__name__ == '__main__'): 
    main()

2. Same Python 3 code as above, but with extensive explanatory comments:

"""
read_keyboard_input.py

Gabriel Staples
www.ElectricRCAircraftGuy.com
14 Nov. 2018

References:
- https://pyserial.readthedocs.io/en/latest/pyserial_api.html
- *****https://www.tutorialspoint.com/python/python_multithreading.htm
- *****https://en.wikibooks.org/wiki/Python_Programming/Threading
- https://stackoverflow.com/questions/1607612/python-how-do-i-make-a-subclass-from-a-superclass
- https://docs.python.org/3/library/queue.html
- https://docs.python.org/3.7/library/threading.html

To install PySerial: `sudo python3 -m pip install pyserial`

To run this program: `python3 this_filename.py`

"""

import threading
import queue
import time

def read_kbd_input(inputQueue):
    print('Ready for keyboard input:')
    while (True):
        # Receive keyboard input from user.
        input_str = input()
        
        # Enqueue this input string.
        # Note: Lock not required here since we are only calling a single Queue method, not a sequence of them 
        # which would otherwise need to be treated as one atomic operation.
        inputQueue.put(input_str)

def main():

    EXIT_COMMAND = "exit" # Command to exit this program

    # The following threading lock is required only if you need to enforce atomic access to a chunk of multiple queue
    # method calls in a row.  Use this if you have such a need, as follows:
    # 1. Pass queueLock as an input parameter to whichever function requires it.
    # 2. Call queueLock.acquire() to obtain the lock.
    # 3. Do your series of queue calls which need to be treated as one big atomic operation, such as calling
    # inputQueue.qsize(), followed by inputQueue.put(), for example.
    # 4. Call queueLock.release() to release the lock.
    # queueLock = threading.Lock() 

    #Keyboard input queue to pass data from the thread reading the keyboard inputs to the main thread.
    inputQueue = queue.Queue()

    # Create & start a thread to read keyboard inputs.
    # Set daemon to True to auto-kill this thread when all other non-daemonic threads are exited. This is desired since
    # this thread has no cleanup to do, which would otherwise require a more graceful approach to clean up then exit.
    inputThread = threading.Thread(target=read_kbd_input, args=(inputQueue,), daemon=True)
    inputThread.start()

    # Main loop
    while (True):

        # Read keyboard inputs
        # Note: if this queue were being read in multiple places we would need to use the queueLock above to ensure
        # multi-method-call atomic access. Since this is the only place we are removing from the queue, however, in this
        # example program, no locks are required.
        if (inputQueue.qsize() > 0):
            input_str = inputQueue.get()
            print("input_str = {}".format(input_str))

            if (input_str == EXIT_COMMAND):
                print("Exiting serial terminal.")
                break # exit the while loop
            
            # Insert your code here to do whatever you want with the input_str.

        # The rest of your program goes here.

        # Sleep for a short time to prevent this thread from sucking up all of your CPU resources on your PC.
        time.sleep(0.01) 
    
    print("End.")

# If you run this Python file directly (ex: via `python3 this_filename.py`), do the following:
if (__name__ == '__main__'): 
    main()

Sample output:

$ python3 read_keyboard_input.py
Ready for keyboard input:
hey
input_str = hey
hello
input_str = hello
7000
input_str = 7000
exit
input_str = exit
Exiting serial terminal.
End.

The Python Queue library is thread-safe:

Note that Queue.put() and Queue.get() and other Queue class methods are thread-safe! That means they implement all the internal locking semantics required for inter-thread operations, so each function call in the queue class can be considered as a single, atomic operation. See the notes at the top of the documentation: https://docs.python.org/3/library/queue.html (emphasis added):

The queue module implements multi-producer, multi-consumer queues. It is especially useful in threaded programming when information must be exchanged safely between multiple threads. The Queue class in this module implements all the required locking semantics.

References:

  1. https://pyserial.readthedocs.io/en/latest/pyserial_api.html
  2. *****https://www.tutorialspoint.com/python/python_multithreading.htm
  3. *****https://en.wikibooks.org/wiki/Python_Programming/Threading
  4. Python: How do I make a subclass from a superclass?
  5. https://docs.python.org/3/library/queue.html
  6. https://docs.python.org/3.7/library/threading.html

Related/Cross-Linked:

  1. PySerial non-blocking read loop

How do I merge two dictionaries in a single expression (taking union of dictionaries)?

It's so silly that .update returns nothing.
I just use a simple helper function to solve the problem:

def merge(dict1,*dicts):
    for dict2 in dicts:
        dict1.update(dict2)
    return dict1

Examples:

merge(dict1,dict2)
merge(dict1,dict2,dict3)
merge(dict1,dict2,dict3,dict4)
merge({},dict1,dict2)  # this one returns a new copy

How to Identify Microsoft Edge browser via CSS?

More accurate for Edge (do not include latest IE 15) is:

@supports (display:-ms-grid) { ... }

@supports (-ms-ime-align:auto) { ... } works for all Edge versions (currently up to IE15).

How do I match any character across multiple lines in a regular expression?

For Eclipse worked following expression:

Foo

jadajada Bar"

Regular-Expression:

Foo[\S\s]{1,10}.*Bar*

Equivalent of explode() to work with strings in MySQL

I faced same issue today and resolved it like below, please note in my case, I know the number of items in the concatenated string, hence I can recover them this way:

set @var1=0;
set @var2=0;
SELECT SUBSTRING_INDEX('value1,value2', ',', 1) into @var1;
SELECT SUBSTRING_INDEX('value1,value2', ',', -1) into @var2;

variables @var1 and @var2 would have the values similar to explode().

How to pass an event object to a function in Javascript?

I would change your binding to be:

<button type="button" value="click me" onclick="check_me" />

I would then change your check_me() function declaration to be:

function check_me() {   
  //event.preventDefault();
  var hello = document.myForm.username.value;
  var err = '';

  if(hello == '' || hello == null) {
    err = 'User name required';
  }

  if(err != '') { 
     alert(err); 
     $('username').focus(); 
     event.preventDefault(); 
   } else { 
    return true; }
}

Add a auto increment primary key to existing table in oracle

If you have the column and the sequence, you first need to populate a new key for all the existing rows. Assuming you don't care which key is assigned to which row

UPDATE table_name
   SET new_pk_column = sequence_name.nextval;

Once that's done, you can create the primary key constraint (this assumes that either there is no existing primary key constraint or that you have already dropped the existing primary key constraint)

ALTER TABLE table_name
  ADD CONSTRAINT pk_table_name PRIMARY KEY( new_pk_column )

If you want to generate the key automatically, you'd need to add a trigger

CREATE TRIGGER trigger_name
  BEFORE INSERT ON table_name
  FOR EACH ROW
BEGIN
  :new.new_pk_column := sequence_name.nextval;
END;

If you are on an older version of Oracle, the syntax is a bit more cumbersome

CREATE TRIGGER trigger_name
  BEFORE INSERT ON table_name
  FOR EACH ROW
BEGIN
  SELECT sequence_name.nextval
    INTO :new.new_pk_column
    FROM dual;
END;

Install sbt on ubuntu

As an alternative approach, you can save the SBT Extras script to a file called sbt.sh and set the permission to executable. Then add this file to your path, or just put it under your ~/bin directory.

The bonus here, is that it will download and use the correct version of SBT depending on your project properties. This is a nice convenience if you tend to compile open source projects that you pull from GitHub and other.

Matrix Transpose in Python

The "best" answer has already been submitted, but I thought I would add that you can use nested list comprehensions, as seen in the Python Tutorial.

Here is how you could get a transposed array:

def matrixTranspose( matrix ):
    if not matrix: return []
    return [ [ row[ i ] for row in matrix ] for i in range( len( matrix[ 0 ] ) ) ]

Get all photos from Instagram which have a specific hashtag with PHP

I have set a php code which can help in case you want to access Instagram images without api on basis of hashtag

Php Code for Instagram hashtag images

Oracle error : ORA-00905: Missing keyword

First, I thought:

"...In Microsoft SQL Server the SELECT...INTO automatically creates the new table whereas Oracle seems to require you to manually create it before executing the SELECT...INTO statement..."

But after manually generating a table, it still did not work, still showing the "missing keyword" error.

So I gave up this time and solved it by first manually creating the table, then using the "classic" SELECT statement:

INSERT INTO assignment_20081120 SELECT * FROM assignment;

Which worked as expected. If anyone come up with an explanaition on how to use the SELECT...INTO in a correct way, I would be happy!

How to set HTML5 required attribute in Javascript?

try out this..

document.getElementById("edName").required = true;

How to write to Console.Out during execution of an MSTest test

I had the same issue and I was "Running" the tests. If I instead "Debug" the tests the Debug output shows just fine like all others Trace and Console. I don't know though how to see the output if you "Run" the tests.

How to select an item from a dropdown list using Selenium WebDriver with java?

Just wrap your WebElement into Select Object as shown below

Select dropdown = new Select(driver.findElement(By.id("identifier")));

Once this is done you can select the required value in 3 ways. Consider an HTML file like this

<html>
<body>
<select id = "designation">
<option value = "MD">MD</option>
<option value = "prog"> Programmer </option>
<option value = "CEO"> CEO </option>
</option>
</select>
<body>
</html>

Now to identify dropdown do

Select dropdown = new Select(driver.findElement(By.id("designation")));

To select its option say 'Programmer' you can do

dropdown.selectByVisibleText("Programmer ");

or

dropdown.selectByIndex(1);

or

dropdown.selectByValue("prog");

Happy Coding :)

Convert a Pandas DataFrame to a dictionary

df = pd.DataFrame([['p',1,3,2], ['q',4,3,2], ['r',4,0,9]], columns=['ID','A','B','C'])
my_dict = {k:list(v) for k,v in zip(df['ID'], df.drop(columns='ID').values)}
print(my_dict)

with output

{'p': [1, 3, 2], 'q': [4, 3, 2], 'r': [4, 0, 9]}

How to execute a raw update sql with dynamic binding in rails

It doesn't look like the Rails API exposes methods to do this generically. You could try accessing the underlying connection and using it's methods, e.g. for MySQL:

st = ActiveRecord::Base.connection.raw_connection.prepare("update table set f1=? where f2=? and f3=?")
st.execute(f1, f2, f3)
st.close

I'm not sure if there are other ramifications to doing this (connections left open, etc). I would trace the Rails code for a normal update to see what it's doing aside from the actual query.

Using prepared queries can save you a small amount of time in the database, but unless you're doing this a million times in a row, you'd probably be better off just building the update with normal Ruby substitution, e.g.

ActiveRecord::Base.connection.execute("update table set f1=#{ActiveRecord::Base.sanitize(f1)}")

or using ActiveRecord like the commenters said.

How to get back to the latest commit after checking out a previous commit?

If your latest commit is on the master branch, you can simply use

git checkout master

Convert JS date time to MySQL datetime

new Date().toISOString().slice(0, 10)+" "+new Date().toLocaleTimeString('en-GB');

Redirect from an HTML page

You should use JavaScript. Place the following code in your head tags:

<script type="text/javascript">
 window.location.assign("http://www.example.com")
</script>

mysql-python install error: Cannot open include file 'config-win.h'

For me, it worked when I selected the correct bit of my Python version, NOT the one of my computer version.

Mine is 32bit, and my computer is 64bit. That was the problem and the 32bit version of fixed it.

to be exact, here is the one that worked for me: mysqlclient-1.3.13-cp37-cp37m-win32.whl

Increment a database field by 1

This is more a footnote to a number of the answers above which suggest the use of ON DUPLICATE KEY UPDATE, BEWARE that this is NOT always replication safe, so if you ever plan on growing beyond a single server, you'll want to avoid this and use two queries, one to verify the existence, and then a second to either UPDATE when a row exists, or INSERT when it does not.

How to increment a pointer address and pointer's value?

        Note:
        1) Both ++ and * have same precedence(priority), so the associativity comes into picture.
        2) in this case Associativity is from **Right-Left**

        important table to remember in case of pointers and arrays: 

        operators           precedence        associativity

    1)  () , []                1               left-right
    2)  *  , identifier        2               right-left
    3)  <data type>            3               ----------

        let me give an example, this might help;

        char **str;
        str = (char **)malloc(sizeof(char*)*2); // allocate mem for 2 char*
        str[0]=(char *)malloc(sizeof(char)*10); // allocate mem for 10 char
        str[1]=(char *)malloc(sizeof(char)*10); // allocate mem for 10 char

        strcpy(str[0],"abcd");  // assigning value
        strcpy(str[1],"efgh");  // assigning value

        while(*str)
        {
            cout<<*str<<endl;   // printing the string
            *str++;             // incrementing the address(pointer)
                                // check above about the prcedence and associativity
        }
        free(str[0]);
        free(str[1]);
        free(str);

Passing string to a function in C - with or without pointers?

Assuming that you meant to write

char *functionname(char *string[256])

Here you are declaring a function that takes an array of 256 pointers to char as argument and returns a pointer to char. Here, on the other hand,

char functionname(char string[256])

You are declaring a function that takes an array of 256 chars as argument and returns a char.

In other words the first function takes an array of strings and returns a string, while the second takes a string and returns a character.

How can I troubleshoot Python "Could not find platform independent libraries <prefix>"

If you made a virtual env, then deleted that python installation, you'll get the same error. Just rm -r your venv folder, then recreate it with a valid python location and do pip install -r requirements.txt and you'll be all set (assuming you got your requirements.txt right).

How can I change CSS display none or block property using jQuery?

you can do it by button

<button onclick"document.getElementById('elementid').style.display = 'none or block';">

Typescript es6 import module "File is not a module error"

The file needs to add Component from core hence add the following import to the top

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

How to convert 2D float numpy array to 2D int numpy array?

If you're not sure your input is going to be a Numpy array, you can use asarray with dtype=int instead of astype:

>>> np.asarray([1,2,3,4], dtype=int)
array([1, 2, 3, 4])

If the input array already has the correct dtype, asarray avoids the array copy while astype does not (unless you specify copy=False):

>>> a = np.array([1,2,3,4])
>>> a is np.asarray(a)  # no copy :)
True
>>> a is a.astype(int)  # copy :(
False
>>> a is a.astype(int, copy=False)  # no copy :)
True

Call to getLayoutInflater() in places not in activity

or

View.inflate(context, layout, parent)

Cannot refer to a non-final variable inside an inner class defined in a different method

You can only access final variables from the containing class when using an anonymous class. Therefore you need to declare the variables being used final (which is not an option for you since you are changing lastPrice and price), or don't use an anonymous class.

So your options are to create an actual inner class, in which you can pass in the variables and use them in a normal fashion

or:

There is a quick (and in my opinion ugly) hack for your lastPrice and price variable which is to declare it like so

final double lastPrice[1];
final double price[1];

and in your anonymous class you can set the value like this

price[0] = priceObject.getNextPrice(lastPrice[0]);
System.out.println();
lastPrice[0] = price[0];

iOS Launching Settings -> Restrictions URL Scheme

AS @Nix Wang's ANSWER THIS IS NOT WORK IN IOS 10


WARNING: This method will not work for devices running iOS 5.1 and greater - See Hlung's comment below.

It's possible that the path component has a different name than the actual section, but it's also possible that you can't currently access that section straight from a URL. I found a list of possible URLs and Restrictions is not on it, maybe it's just not found out yet.

List of currently known URLs in the Settings app:

  • prefs:root=General&path=About
  • prefs:root=General&path=ACCESSIBILITY
  • prefs:root=AIRPLANE_MODE
  • prefs:root=General&path=AUTOLOCK
  • prefs:root=General&path=USAGE/CELLULAR_USAGE
  • prefs:root=Brightness
  • prefs:root=General&path=Bluetooth
  • prefs:root=General&path=DATE_AND_TIME
  • prefs:root=FACETIME
  • prefs:root=General
  • prefs:root=General&path=Keyboard
  • prefs:root=CASTLE
  • prefs:root=CASTLE&path=STORAGE_AND_BACKUP
  • prefs:root=General&path=INTERNATIONAL
  • prefs:root=LOCATION_SERVICES
  • prefs:root=ACCOUNT_SETTINGS
  • prefs:root=MUSIC
  • prefs:root=MUSIC&path=EQ
  • prefs:root=MUSIC&path=VolumeLimit
  • prefs:root=General&path=Network
  • prefs:root=NIKE_PLUS_IPOD
  • prefs:root=NOTES
  • prefs:root=NOTIFICATIONS_ID
  • prefs:root=Phone
  • prefs:root=Photos
  • prefs:root=General&path=ManagedConfigurationList
  • prefs:root=General&path=Reset
  • prefs:root=Sounds&path=Ringtone
  • prefs:root=Safari
  • prefs:root=General&path=Assistant
  • prefs:root=Sounds
  • prefs:root=General&path=SOFTWARE_UPDATE_LINK
  • prefs:root=STORE
  • prefs:root=TWITTER
  • prefs:root=General&path=USAGE
  • prefs:root=VIDEO
  • prefs:root=General&path=Network/VPN
  • prefs:root=Wallpaper
  • prefs:root=WIFI
  • prefs:root=INTERNET_TETHERING

Reading output of a command into an array in Bash

You can use

my_array=( $(<command>) )

to store the output of command <command> into the array my_array.

You can access the length of that array using

my_array_length=${#my_array[@]}

Now the length is stored in my_array_length.

mvn clean install vs. deploy vs. release

The clean, install and deploy phases are valid lifecycle phases and invoking them will trigger all the phases preceding them, and the goals bound to these phases.

mvn clean install

This command invokes the clean phase and then the install phase sequentially:

  • clean: removes files generated at build-time in a project's directory (target by default)
  • install: installs the package into the local repository, for use as a dependency in other projects locally.

mvn deploy

This command invokes the deploy phase:

  • deploy: copies the final package to the remote repository for sharing with other developers and projects.

mvn release

This is not a valid phase nor a goal so this won't do anything. But if refers to the Maven Release Plugin that is used to automate release management. Releasing a project is done in two steps: prepare and perform. As documented:

Preparing a release goes through the following release phases:

  • Check that there are no uncommitted changes in the sources
  • Check that there are no SNAPSHOT dependencies
  • Change the version in the POMs from x-SNAPSHOT to a new version (you will be prompted for the versions to use)
  • Transform the SCM information in the POM to include the final destination of the tag
  • Run the project tests against the modified POMs to confirm everything is in working order
  • Commit the modified POMs
  • Tag the code in the SCM with a version name (this will be prompted for)
  • Bump the version in the POMs to a new value y-SNAPSHOT (these values will also be prompted for)
  • Commit the modified POMs

And then:

Performing a release runs the following release phases:

  • Checkout from an SCM URL with optional tag
  • Run the predefined Maven goals to release the project (by default, deploy site-deploy)

See also

Implementing SearchView in action bar

If anyone else is having a nullptr on the searchview variable, I found out that the item setup is a tiny bit different:

old:

android:showAsAction="ifRoom"
android:actionViewClass="android.widget.SearchView"

new:

app:showAsAction="ifRoom|collapseActionView"
app:actionViewClass="androidx.appcompat.widget.SearchView"

pre-android x:

app:showAsAction="ifRoom|collapseActionView"
app:actionViewClass="android.support.v7.widget.SearchView"

For more information, it's updated documentation is located here.

Sticky and NON-Sticky sessions

When your website is served by only one web server, for each client-server pair, a session object is created and remains in the memory of the web server. All the requests from the client go to this web server and update this session object. If some data needs to be stored in the session object over the period of interaction, it is stored in this session object and stays there as long as the session exists.

However, if your website is served by multiple web servers which sit behind a load balancer, the load balancer decides which actual (physical) web-server should each request go to. For example, if there are 3 web servers A, B and C behind the load balancer, it is possible that www.mywebsite.com/index.jsp is served from server A, www.mywebsite.com/login.jsp is served from server B and www.mywebsite.com/accoutdetails.php are served from server C.

Now, if the requests are being served from (physically) 3 different servers, each server has created a session object for you and because these session objects sit on three independent boxes, there's no direct way of one knowing what is there in the session object of the other. In order to synchronize between these server sessions, you may have to write/read the session data into a layer which is common to all - like a DB. Now writing and reading data to/from a db for this use-case may not be a good idea. Now, here comes the role of sticky-session.

If the load balancer is instructed to use sticky sessions, all of your interactions will happen with the same physical server, even though other servers are present. Thus, your session object will be the same throughout your entire interaction with this website.

To summarize, In case of Sticky Sessions, all your requests will be directed to the same physical web server while in case of a non-sticky loadbalancer may choose any webserver to serve your requests.

As an example, you may read about Amazon's Elastic Load Balancer and sticky sessions here : http://aws.typepad.com/aws/2010/04/new-elastic-load-balancing-feature-sticky-sessions.html

How to disable spring security for particular url

<http pattern="/resources/**" security="none"/>

Or with Java configuration:

web.ignoring().antMatchers("/resources/**");

Instead of the old:

 <intercept-url pattern="/resources/**" filters="none"/>

for exp . disable security for a login page :

  <intercept-url pattern="/login*" filters="none" />

Concatenation of strings in Lua

If you are asking whether there's shorthand version of operator .. - no there isn't. You cannot write a ..= b. You'll have to type it in full: filename = filename .. ".tmp"

How do you know if Tomcat Server is installed on your PC

In case of Windows(in my case XP):-

  1. Check the directory where tomcat is installed.
  2. Open the directory called \conf in it.
  3. Then search file server.xml
  4. Open that file and check what is the connector port for HTTP,whre you will found something like 8009,8080 etc.
  5. Suppose it found 8009,use that port as "/localhost:8009/" in your web-browser with HTTP protocol. Hope this will work !

How to hide the border for specified rows of a table?

You can simply add these lines of codes here to hide a row,

Either you can write border:0 or border-style:hidden; border: none or it will happen the same thing

_x000D_
_x000D_
<style type="text/css">_x000D_
              table, th, td {_x000D_
               border: 1px solid;_x000D_
              }_x000D_
              _x000D_
              tr.hide_all > td, td.hide_all{_x000D_
                 border: 0;_x000D_
                _x000D_
              }_x000D_
          }_x000D_
        </style>_x000D_
    <table>_x000D_
      <tr>_x000D_
        <th>Firstname</th>_x000D_
        <th>Lastname</th>_x000D_
        <th>Savings</th>_x000D_
      </tr>_x000D_
      <tr>_x000D_
        <td>Peter</td>_x000D_
        <td>Griffin</td>_x000D_
        <td>$100</td>_x000D_
      </tr>_x000D_
      <tr class= hide_all>_x000D_
        <td>Lois</td>_x000D_
        <td>Griffin</td>_x000D_
        <td>$150</td>_x000D_
      </tr>_x000D_
      <tr>_x000D_
        <td>Joe</td>_x000D_
        <td>Swanson</td>_x000D_
        <td>$300</td>_x000D_
      </tr>_x000D_
      <tr>_x000D_
        <td>Cleveland</td>_x000D_
        <td>Brown</td>_x000D_
        <td>$250</td>_x000D_
      </tr>_x000D_
    </table>
_x000D_
_x000D_
_x000D_

running these lines of codes can solve the problem easily

Get the string within brackets in Python

This should do the job:

re.match(r"[^[]*\[([^]]*)\]", yourstring).groups()[0]

Receiving login prompt using integrated windows authentication

If your URL has dots in the domain name, IE will treat it like it's an internet address and not local. You have at least two options:

  1. Get an alias to use in the URL to replace server.domain. For example, myapp.
  2. Follow the steps below on your computer.

Go to the site and cancel the login dialog. Let this happen:

enter image description here

In IE’s settings:

enter image description here

enter image description here

enter image description here

How to validate a file upload field using Javascript/jquery

Simple and powerful way(dynamic validation)

place formats in array like "image/*"

_x000D_
_x000D_
var upload=document.getElementById("upload");
var array=["video/mp4","image/png"];
upload.accept=array;
upload.addEventListener("change",()=>{

console.log(upload.value)
})
_x000D_
<input type="file" id="upload" >
_x000D_
_x000D_
_x000D_

How to customize the configuration file of the official PostgreSQL Docker image?

My solution is for colleagues who needs to make changes in config before launching docker-entrypoint-initdb.d

I was needed to change 'shared_preload_libraries' setting so during it's work postgres already has new library preloaded and code in docker-entrypoint-initdb.d can use it.

So I just patched postgresql.conf.sample file in Dockerfile:

RUN echo "shared_preload_libraries='citus,pg_cron'" >> /usr/share/postgresql/postgresql.conf.sample
RUN echo "cron.database_name='newbie'" >> /usr/share/postgresql/postgresql.conf.sample

And with this patch it become possible to add extension in .sql file in docker-entrypoint-initdb.d/:

CREATE EXTENSION pg_cron;

Using BeautifulSoup to extract text without tags

I think you could solve this with .strip() in gazpacho:

Input:

html = """\
<p>
  <strong class="offender">YOB:</strong> 1987<br />
  <strong class="offender">RACE:</strong> WHITE<br />
  <strong class="offender">GENDER:</strong> FEMALE<br />
  <strong class="offender">HEIGHT:</strong> 5'05''<br />
  <strong class="offender">WEIGHT:</strong> 118<br />
  <strong class="offender">EYE COLOR:</strong> GREEN<br />
  <strong class="offender">HAIR COLOR:</strong> BROWN<br />
</p>
"""

Code:

soup = Soup(html)
text = soup.find("p").strip(whitespace=False) # to keep \n characters intact
lines = [
    line.strip()
    for line in text.split("\n")
    if line != ""
]
data = dict([line.split(": ") for line in lines])

Output:

print(data)
# {'YOB': '1987',
#  'RACE': 'WHITE',
#  'GENDER': 'FEMALE',
#  'HEIGHT': "5'05''",
#  'WEIGHT': '118',
#  'EYE COLOR': 'GREEN',
#  'HAIR COLOR': 'BROWN'}

How can I trigger another job from a jenkins pipeline (jenkinsfile) with GitHub Org Plugin?

First of all, it is a waste of an executor slot to wrap the build step in node. Your upstream executor will just be sitting idle for no reason.

Second, from a multibranch project, you can use the environment variable BRANCH_NAME to make logic conditional on the current branch.

Third, the job parameter takes an absolute or relative job name. If you give a name without any path qualification, that would refer to another job in the same folder, which in the case of a multibranch project would mean another branch of the same repository.

Thus what you meant to write is probably

if (env.BRANCH_NAME == 'master') {
    build '../other-repo/master'
}

printf a variable in C

As Shafik already wrote you need to use the right format because scanf gets you a char. Don't hesitate to look here if u aren't sure about the usage: http://www.cplusplus.com/reference/cstdio/printf/

Hint: It's faster/nicer to write x=x+1; the shorter way: x++;

Sorry for answering what's answered just wanted to give him the link - the site was really useful to me all the time dealing with C.