Programs & Examples On #Register allocation

register allocation is the process of assigning a large number of target program variables onto a small number of available CPU registers.

Getting specified Node values from XML document

Just like you do for getting something from the CNode you also need to do for the ANode

XmlNodeList xnList = xml.SelectNodes("/Element[@*]");
foreach (XmlNode xn in xnList)
{
  XmlNode anode = xn.SelectSingleNode("ANode");
    if (anode!= null)
    {
        string id = anode["ID"].InnerText;
        string date = anode["Date"].InnerText;
        XmlNodeList CNodes = xn.SelectNodes("ANode/BNode/CNode");
        foreach (XmlNode node in CNodes)
        {
         XmlNode example = node.SelectSingleNode("Example");
         if (example != null)
         {
            string na = example["Name"].InnerText;
            string no = example["NO"].InnerText;
         }
        }
    }
}

How to add line break for UILabel?

// DO not forget to set numberOfLines to zero

UILabel* locationTitle = [[UILabel alloc] initWithFrame:CGRectMake(5, 30, 230, 40)];
locationTitle.font = [UIFont systemFontOfSize:13.0];
locationTitle.numberOfLines = 0;
locationTitle.text = [NSString stringWithFormat:@"Eaton industries pvt. Ltd \nUK Apr 12"];
[cell addSubview:locationTitle];

Is it possible to use Visual Studio on macOS?

Yes, you can! There's a Visual Studio for macs and there's Visual Studio Code if you only need a text editor like Sublime Text.

Select element by exact match of its content

No, there's no jQuery (or CSS) selector that does that.

You can readily use filter:

$("p").filter(function() {
    return $(this).text() === "hello";
}).css("font-weight", "bold");

It's not a selector, but it does the job. :-)

If you want to handle whitespace before or after the "hello", you might throw a $.trim in there:

return $.trim($(this).text()) === "hello";

For the premature optimizers out there, if you don't care that it doesn't match <p><span>hello</span></p> and similar, you can avoid the calls to $ and text by using innerHTML directly:

return this.innerHTML === "hello";

...but you'd have to have a lot of paragraphs for it to matter, so many that you'd probably have other issues first. :-)

How to JSON decode array elements in JavaScript?

JSON decoding in JavaScript is simply an eval() if you trust the string or the more safe code you can find on http://json.org if you don't.

You will then have a JavaScript datastructure that you can traverse for the data you need.

How to get video duration, dimension and size in PHP?

If you use Wordpress you can just use the wordpress build in function with the video id provided wp_get_attachment_metadata($videoID):

wp_get_attachment_metadata($videoID);

helped me a lot. thats why i'm posting it, although its just for wordpress users.

How can I ssh directly to a particular directory?

going one step further with the -t idea. I keep a set of scripts calling the one below to go to specific places in my frequently visited hosts. I keep them all in ~/bin and keep that directory in my path.

#!/bin/bash

# does ssh session switching to particular directory
# $1, hostname from config file 
# $2, directory to move to after login
# can save this as say 'con' then
# make another script calling this one, e.g.
# con myhost repos/i2c

ssh -t $1 "cd $2; exec \$SHELL --login"

Deploying Java webapp to Tomcat 8 running in Docker container

You are trying to copy the war file to a directory below webapps. The war file should be copied into the webapps directory.

Remove the mkdir command, and copy the war file like this:

COPY /1.0-SNAPSHOT/my-app-1.0-SNAPSHOT.war /usr/local/tomcat/webapps/myapp.war

Tomcat will extract the war if autodeploy is turned on.

What is the javascript filename naming convention?

The question in the link you gave talks about naming of JavaScript variables, not about file naming, so forget about that for the context in which you ask your question.

As to file naming, it is purely a matter of preference and taste. I prefer naming files with hyphens because then I don't have to reach for the shift key, as I do when dealing with camelCase file names; and because I don't have to worry about differences between Windows and Linux file names (Windows file names are case-insensitive, at least through XP).

So the answer, like so many, is "it depends" or "it's up to you."

The one rule you should follow is to be consistent in the convention you choose.

Alternative to Intersect in MySQL

Break your problem in 2 statements: firstly, you want to select all if

(id=3 and cut_name= '?????' and cut_name='??')

is true . Secondly, you want to select all if

(id=3) and ( cut_name='?????' or cut_name='??')

is true. So, we will join both by OR because we want to select all if anyone of them is true.

select * from emovis_reporting
    where (id=3 and cut_name= '?????' and cut_name='??') OR
        ( (id=3) and ( cut_name='?????' or cut_name='??') )

prevent property from being serialized in web API

For .NET Core 3.0 and above:

The default JSON serializer for ASP.NET Core is now System.Text.Json, which is new in .NET Core 3.0. Consider using System.Text.Json when possible. It's high-performance and doesn't require an additional library dependency.

https://docs.microsoft.com/en-us/aspnet/core/migration/22-to-30?view=aspnetcore-3.1&tabs=visual-studio#newtonsoftjson-jsonnet-support

Sample (Thanks cuongle)

using System.Text.Json.Serialization;

public class Foo
{
    public int Id { get; set; }
    public string Name { get; set; }

    [JsonIgnore]
    public List<Something> Somethings { get; set; }
}

If you already have Newtonsoft.Json intalled and chose to use it instead, by default, [JsonIgnore] won't work as expected.

Vector of structs initialization

You may also which to use aggregate initialization from a braced initialization list for situations like these.

#include <vector>
using namespace std;

struct subject {
    string name;
    int    marks;
    int    credits;
};

int main() {
    vector<subject> sub {
      {"english", 10, 0},
      {"math"   , 20, 5}
    };
}

Sometimes however, the members of a struct may not be so simple, so you must give the compiler a hand in deducing its types.

So extending on the above.

#include <vector>
using namespace std;

struct assessment {
    int   points;
    int   total;
    float percentage;
};

struct subject {
    string name;
    int    marks;
    int    credits;
    vector<assessment> assessments;
};

int main() {
    vector<subject> sub {
      {"english", 10, 0, {
                             assessment{1,3,0.33f},
                             assessment{2,3,0.66f},
                             assessment{3,3,1.00f}
                         }},
      {"math"   , 20, 5, {
                             assessment{2,4,0.50f}
                         }}
    };
}

Without the assessment in the braced initializer the compiler will fail when attempting to deduce the type.

The above has been compiled and tested with gcc in c++17. It should however work from c++11 and onward. In c++20 we may see the designator syntax, my hope is that it will allow for for the following

  {"english", 10, 0, .assessments{
                         {1,3,0.33f},
                         {2,3,0.66f},
                         {3,3,1.00f}
                     }},

source: http://en.cppreference.com/w/cpp/language/aggregate_initialization

PHPmailer sending HTML CODE

all you need to do is just add $mail->IsHTML(true); to the code it works fine..

Spring Bean Scopes

Also websocket scope is added:

Scopes a single bean definition to the lifecycle of a WebSocket. Only valid in the context of a web-aware Spring ApplicationContext.

As the per the content of the documentation, there is also thread scope, that is not registered by default.

jQuery UI Color Picker

Had the same problem (is not a method) with jQuery when working on autocomplete. It appeared the code was executed before the autocomplete.js was loaded. So make sure the ui.colorpicker.js is loaded before calling colorpicker.

Convert multiple rows into one with comma as separator

A clean and flexible solution in MS SQL Server 2005/2008 is to create a CLR Agregate function.

You'll find quite a few articles (with code) on google.

It looks like this article walks you through the whole process using C#.

How do I pass a method as a parameter in Python

Methods are objects like any other. So you can pass them around, store them in lists and dicts, do whatever you like with them. The special thing about them is they are callable objects so you can invoke __call__ on them. __call__ gets called automatically when you invoke the method with or without arguments so you just need to write methodToRun().

FirstOrDefault: Default value other than null

You can use DefaultIfEmpty followed by First:

T customDefault = ...;
IEnumerable<T> mySequence = ...;
mySequence.DefaultIfEmpty(customDefault).First();

How can I run specific migration in laravel

use this command php artisan migrate --path=/database/migrations/my_migration.php it worked for me..

Case insensitive comparison of strings in shell script

For zsh the syntax is slightly different, but still shorter than most answers here:

> str1='mAtCh'
> str2='MaTcH'
> [[ "$str1:u" = "$str2:u" ]] && echo 'Strings Match!'
Strings Match!
>

This will convert both strings to uppercase before the comparison.


Another method makes use zsh's globbing flags, which allows us to directly make use of case-insensitive matching by using the i glob flag:

setopt extendedglob
[[ $str1 = (#i)$str2 ]] && echo "Match success"
[[ $str1 = (#i)match ]] && echo "Match success"

Write to text file without overwriting in Java

JFileChooser c= new JFileChooser();
c.showOpenDialog(c);
File write_file = c.getSelectedFile();
String Content = "put here the data to be wriiten";
try
    {
    FileWriter fw = new FileWriter(write_file);
    BufferedWriter bw = new BufferedWriter(fw);
    bw.append(Content);
    bw.append("hiiiii");
    bw.close();
    fw.close();
    }
catch(Exception e)
   {
    System.out.println(e);
   `}

How to create a signed APK file using Cordova command line interface?

An update to @malcubierre for Cordova 4 (and later)-

Create a file called release-signing.properties and put in APPFOLDER\platforms\android folder

Contents of the file: edit after = for all except 2nd line

storeFile=C:/yourlocation/app.keystore
storeType=jks
keyAlias=aliasname
keyPassword=aliaspass
storePassword=password

Then this command should build a release version:

cordova build android --release

UPDATE - This was not working for me Cordova 10 with android 9 - The build was replacing the release-signing.properties file. I had to make a build.json file and drop it in the appfolder, same as root. And this is the contents - replace as above:

{
"android": {
    "release": {
       "keystore": "C:/yourlocation/app.keystore",
        "storePassword": "password",
        "alias": "aliasname",
        "password" : "aliaspass",
        "keystoreType": ""
    }
}
}

Run it and it will generate one of those release-signing.properties in the android folder

'if' statement in jinja2 template

Why the loop?

You could simply do this:

{% if 'priority' in data %}
    <p>Priority: {{ data['priority'] }}</p>
{% endif %}

When you were originally doing your string comparison, you should have used == instead.

curl -GET and -X GET

The use of -X [WHATEVER] merely changes the request's method string used in the HTTP request. This is easier to understand with two examples — one with -X [WHATEVER] and one without — and the associated HTTP request headers for each:

# curl -XPANTS -o nul -v http://neverssl.com/
* Connected to neverssl.com (13.224.86.126) port 80 (#0)
> PANTS / HTTP/1.1
> Host: neverssl.com
> User-Agent: curl/7.42.0
> Accept: */*

# curl -o nul -v http://neverssl.com/
* Connected to neverssl.com (13.33.50.167) port 80 (#0)
> GET / HTTP/1.1
> Host: neverssl.com
> User-Agent: curl/7.42.0
> Accept: */*

Why is php not running?

One big gotcha is that PHP is disabled in user home directories by default, so if you are testing from ~/public_html it doesn't work. Check /etc/apache2/mods-enabled/php5.conf

# Running PHP scripts in user directories is disabled by default
# 
# To re-enable PHP in user directories comment the following lines
# (from <IfModule ...> to </IfModule>.) Do NOT set it to On as it
# prevents .htaccess files from disabling it.
#<IfModule mod_userdir.c>
#    <Directory /home/*/public_html>
#        php_admin_flag engine Off
#    </Directory>
#</IfModule>

Other than that installing in Ubuntu is real easy, as all the stuff you used to have to put in httpd.conf is done automatically.

Prevent PDF file from downloading and printing

Okay, I take back what I commented earlier. Just talked to one of the senior guys in my shop and he said it is possible to lock it down hard. What you can do is convert the pdf to an image/flash/whatever and wrap it in an iFrame. Then, you create another image with 100% transparency and lay it over top the iFrame (not in it) and set it to have a higher Z-value than the iFrame.

What this will do is that if they right click on the 'image' to save it, they will be saving the transparent image instead. And since the image 'overrides' the iFrame, any attempt to use print screen should be shielded by the image, and they should only be able to snapshot the image that doesn't actually exist.

That leaves only one or two ways to get at the file...which requires digging straight into the source code to find the image file inside the iFrame. Still not totally secure, but protected from your average user.

AccessDenied for ListObjects for S3 bucket when permissions are s3:*

I faced with the same issue. I just added credentials config:

aws_access_key_id = your_aws_access_key_id
aws_secret_access_key = your_aws_secret_access_key

into "~/.aws/credentials" + restart terminal for default profile.

In the case of multi profiles --profile arg needs to be added:

aws s3 sync ./localDir s3://bucketName --profile=${PROFILE_NAME}

where PROFILE_NAME:

.bash_profile ( or .bashrc) -> export PROFILE_NAME="yourProfileName"

More info about how to config credentials and multi profiles can be found here

Landscape printing from HTML

You might be able to use the CSS 2 @page rule which allows you to set the 'size' property to landscape.

Set an empty DateTime variable

You can set a DateTime variable to be '1/1/0001 00:00:00' but the variable itself cannot be null. To get this MinTime use:

DateTime variableName = DateTime.MinValue;

Is it possible to indent JavaScript code in Notepad++?

I think you want a code beautifier, this one looks quick and easy: http://jsbeautifier.org/

Is there any kind of hash code function in JavaScript?

I put together a small JavaScript module a while ago to produce hashcodes for strings, objects, arrays, etc. (I just committed it to GitHub :) )

Usage:

Hashcode.value("stackoverflow")
// -2559914341
Hashcode.value({ 'site' : "stackoverflow" })
// -3579752159

Virtual Serial Port for Linux

Use socat for this:

For example:

socat PTY,link=/dev/ttyS10 PTY,link=/dev/ttyS11

Pick images of root folder from sub-folder

You can reference the image using relative path:

<img src="../images/logo.png">
          __ ______ ________
          |    |       |
          |    |       |___ 3. Get the file named "logo.png"
          |    |
          |    |___ 2. Go inside "images/" subdirectory
          | 
          | 
          |____ 1. Go one level up

Or you can use absolute path: / means that this is an absolute path on the server, So if your server is at https://example.org/, referencing /images/logo.png from any page would point to https://example.org/images/logo.png

<img src="/images/logo.png">
          |______ ________
          |    |       |
          |    |       |___ 3. Get the file named "logo.png"
          |    |
          |    |___ 2. Go inside "images/" subdirectory
          | 
          | 
          |____ 1. Go to the root folder

Callback when DOM is loaded in react.js

You can watch your container element using the useRef hook. Note that you need to watch the ref's current value specifically, otherwise it won't work.

Example:

  const containerRef = useRef();
  const { current } = containerRef;

  useEffect(setLinksData, [current]);

return (
    <div ref={containerRef}>
      // your child elements...
    </div>
)

How to detect if JavaScript is disabled?

You might, for instance, use something like document.location = 'java_page.html' to redirect the browser to a new, script-laden page. Failure to redirect implies that JavaScript is unavailable, in which case you can either resort to CGI ro utines or insert appropriate code between the tags. (NOTE: NOSCRIPT is only available in Netscape Navigator 3.0 and up.)

credit http://www.intranetjournal.com/faqs/jsfaq/how12.html

What's the difference between eval, exec, and compile?

The short answer, or TL;DR

Basically, eval is used to evaluate a single dynamically generated Python expression, and exec is used to execute dynamically generated Python code only for its side effects.

eval and exec have these two differences:

  1. eval accepts only a single expression, exec can take a code block that has Python statements: loops, try: except:, class and function/method definitions and so on.

    An expression in Python is whatever you can have as the value in a variable assignment:

    a_variable = (anything you can put within these parentheses is an expression)
    
  2. eval returns the value of the given expression, whereas exec ignores the return value from its code, and always returns None (in Python 2 it is a statement and cannot be used as an expression, so it really does not return anything).

In versions 1.0 - 2.7, exec was a statement, because CPython needed to produce a different kind of code object for functions that used exec for its side effects inside the function.

In Python 3, exec is a function; its use has no effect on the compiled bytecode of the function where it is used.


Thus basically:

>>> a = 5
>>> eval('37 + a')   # it is an expression
42
>>> exec('37 + a')   # it is an expression statement; value is ignored (None is returned)
>>> exec('a = 47')   # modify a global variable as a side effect
>>> a
47
>>> eval('a = 47')  # you cannot evaluate a statement
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    a = 47
      ^
SyntaxError: invalid syntax

The compile in 'exec' mode compiles any number of statements into a bytecode that implicitly always returns None, whereas in 'eval' mode it compiles a single expression into bytecode that returns the value of that expression.

>>> eval(compile('42', '<string>', 'exec'))  # code returns None
>>> eval(compile('42', '<string>', 'eval'))  # code returns 42
42
>>> exec(compile('42', '<string>', 'eval'))  # code returns 42,
>>>                                          # but ignored by exec

In the 'eval' mode (and thus with the eval function if a string is passed in), the compile raises an exception if the source code contains statements or anything else beyond a single expression:

>>> compile('for i in range(3): print(i)', '<string>', 'eval')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    for i in range(3): print(i)
      ^
SyntaxError: invalid syntax

Actually the statement "eval accepts only a single expression" applies only when a string (which contains Python source code) is passed to eval. Then it is internally compiled to bytecode using compile(source, '<string>', 'eval') This is where the difference really comes from.

If a code object (which contains Python bytecode) is passed to exec or eval, they behave identically, excepting for the fact that exec ignores the return value, still returning None always. So it is possible use eval to execute something that has statements, if you just compiled it into bytecode before instead of passing it as a string:

>>> eval(compile('if 1: print("Hello")', '<string>', 'exec'))
Hello
>>>

works without problems, even though the compiled code contains statements. It still returns None, because that is the return value of the code object returned from compile.

In the 'eval' mode (and thus with the eval function if a string is passed in), the compile raises an exception if the source code contains statements or anything else beyond a single expression:

>>> compile('for i in range(3): print(i)', '<string>'. 'eval')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    for i in range(3): print(i)
      ^
SyntaxError: invalid syntax

The longer answer, a.k.a the gory details

exec and eval

The exec function (which was a statement in Python 2) is used for executing a dynamically created statement or program:

>>> program = '''
for i in range(3):
    print("Python is cool")
'''
>>> exec(program)
Python is cool
Python is cool
Python is cool
>>> 

The eval function does the same for a single expression, and returns the value of the expression:

>>> a = 2
>>> my_calculation = '42 * a'
>>> result = eval(my_calculation)
>>> result
84

exec and eval both accept the program/expression to be run either as a str, unicode or bytes object containing source code, or as a code object which contains Python bytecode.

If a str/unicode/bytes containing source code was passed to exec, it behaves equivalently to:

exec(compile(source, '<string>', 'exec'))

and eval similarly behaves equivalent to:

eval(compile(source, '<string>', 'eval'))

Since all expressions can be used as statements in Python (these are called the Expr nodes in the Python abstract grammar; the opposite is not true), you can always use exec if you do not need the return value. That is to say, you can use either eval('my_func(42)') or exec('my_func(42)'), the difference being that eval returns the value returned by my_func, and exec discards it:

>>> def my_func(arg):
...     print("Called with %d" % arg)
...     return arg * 2
... 
>>> exec('my_func(42)')
Called with 42
>>> eval('my_func(42)')
Called with 42
84
>>> 

Of the 2, only exec accepts source code that contains statements, like def, for, while, import, or class, the assignment statement (a.k.a a = 42), or entire programs:

>>> exec('for i in range(3): print(i)')
0
1
2
>>> eval('for i in range(3): print(i)')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    for i in range(3): print(i)
      ^
SyntaxError: invalid syntax

Both exec and eval accept 2 additional positional arguments - globals and locals - which are the global and local variable scopes that the code sees. These default to the globals() and locals() within the scope that called exec or eval, but any dictionary can be used for globals and any mapping for locals (including dict of course). These can be used not only to restrict/modify the variables that the code sees, but are often also used for capturing the variables that the executed code creates:

>>> g = dict()
>>> l = dict()
>>> exec('global a; a, b = 123, 42', g, l)
>>> g['a']
123
>>> l
{'b': 42}

(If you display the value of the entire g, it would be much longer, because exec and eval add the built-ins module as __builtins__ to the globals automatically if it is missing).

In Python 2, the official syntax for the exec statement is actually exec code in globals, locals, as in

>>> exec 'global a; a, b = 123, 42' in g, l

However the alternate syntax exec(code, globals, locals) has always been accepted too (see below).

compile

The compile(source, filename, mode, flags=0, dont_inherit=False, optimize=-1) built-in can be used to speed up repeated invocations of the same code with exec or eval by compiling the source into a code object beforehand. The mode parameter controls the kind of code fragment the compile function accepts and the kind of bytecode it produces. The choices are 'eval', 'exec' and 'single':

  • 'eval' mode expects a single expression, and will produce bytecode that when run will return the value of that expression:

    >>> dis.dis(compile('a + b', '<string>', 'eval'))
      1           0 LOAD_NAME                0 (a)
                  3 LOAD_NAME                1 (b)
                  6 BINARY_ADD
                  7 RETURN_VALUE
    
  • 'exec' accepts any kinds of python constructs from single expressions to whole modules of code, and executes them as if they were module top-level statements. The code object returns None:

    >>> dis.dis(compile('a + b', '<string>', 'exec'))
      1           0 LOAD_NAME                0 (a)
                  3 LOAD_NAME                1 (b)
                  6 BINARY_ADD
                  7 POP_TOP                             <- discard result
                  8 LOAD_CONST               0 (None)   <- load None on stack
                 11 RETURN_VALUE                        <- return top of stack
    
  • 'single' is a limited form of 'exec' which accepts a source code containing a single statement (or multiple statements separated by ;) if the last statement is an expression statement, the resulting bytecode also prints the repr of the value of that expression to the standard output(!).

    An if-elif-else chain, a loop with else, and try with its except, else and finally blocks is considered a single statement.

    A source fragment containing 2 top-level statements is an error for the 'single', except in Python 2 there is a bug that sometimes allows multiple toplevel statements in the code; only the first is compiled; the rest are ignored:

    In Python 2.7.8:

    >>> exec(compile('a = 5\na = 6', '<string>', 'single'))
    >>> a
    5
    

    And in Python 3.4.2:

    >>> exec(compile('a = 5\na = 6', '<string>', 'single'))
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
      File "<string>", line 1
        a = 5
            ^
    SyntaxError: multiple statements found while compiling a single statement
    

    This is very useful for making interactive Python shells. However, the value of the expression is not returned, even if you eval the resulting code.

Thus greatest distinction of exec and eval actually comes from the compile function and its modes.


In addition to compiling source code to bytecode, compile supports compiling abstract syntax trees (parse trees of Python code) into code objects; and source code into abstract syntax trees (the ast.parse is written in Python and just calls compile(source, filename, mode, PyCF_ONLY_AST)); these are used for example for modifying source code on the fly, and also for dynamic code creation, as it is often easier to handle the code as a tree of nodes instead of lines of text in complex cases.


While eval only allows you to evaluate a string that contains a single expression, you can eval a whole statement, or even a whole module that has been compiled into bytecode; that is, with Python 2, print is a statement, and cannot be evalled directly:

>>> eval('for i in range(3): print("Python is cool")')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    for i in range(3): print("Python is cool")
      ^
SyntaxError: invalid syntax

compile it with 'exec' mode into a code object and you can eval it; the eval function will return None.

>>> code = compile('for i in range(3): print("Python is cool")',
                   'foo.py', 'exec')
>>> eval(code)
Python is cool
Python is cool
Python is cool

If one looks into eval and exec source code in CPython 3, this is very evident; they both call PyEval_EvalCode with same arguments, the only difference being that exec explicitly returns None.

Syntax differences of exec between Python 2 and Python 3

One of the major differences in Python 2 is that exec is a statement and eval is a built-in function (both are built-in functions in Python 3). It is a well-known fact that the official syntax of exec in Python 2 is exec code [in globals[, locals]].

Unlike majority of the Python 2-to-3 porting guides seem to suggest, the exec statement in CPython 2 can be also used with syntax that looks exactly like the exec function invocation in Python 3. The reason is that Python 0.9.9 had the exec(code, globals, locals) built-in function! And that built-in function was replaced with exec statement somewhere before Python 1.0 release.

Since it was desirable to not break backwards compatibility with Python 0.9.9, Guido van Rossum added a compatibility hack in 1993: if the code was a tuple of length 2 or 3, and globals and locals were not passed into the exec statement otherwise, the code would be interpreted as if the 2nd and 3rd element of the tuple were the globals and locals respectively. The compatibility hack was not mentioned even in Python 1.4 documentation (the earliest available version online); and thus was not known to many writers of the porting guides and tools, until it was documented again in November 2012:

The first expression may also be a tuple of length 2 or 3. In this case, the optional parts must be omitted. The form exec(expr, globals) is equivalent to exec expr in globals, while the form exec(expr, globals, locals) is equivalent to exec expr in globals, locals. The tuple form of exec provides compatibility with Python 3, where exec is a function rather than a statement.

Yes, in CPython 2.7 that it is handily referred to as being a forward-compatibility option (why confuse people over that there is a backward compatibility option at all), when it actually had been there for backward-compatibility for two decades.

Thus while exec is a statement in Python 1 and Python 2, and a built-in function in Python 3 and Python 0.9.9,

>>> exec("print(a)", globals(), {'a': 42})
42

has had identical behaviour in possibly every widely released Python version ever; and works in Jython 2.5.2, PyPy 2.3.1 (Python 2.7.6) and IronPython 2.6.1 too (kudos to them following the undocumented behaviour of CPython closely).

What you cannot do in Pythons 1.0 - 2.7 with its compatibility hack, is to store the return value of exec into a variable:

Python 2.7.11+ (default, Apr 17 2016, 14:00:29) 
[GCC 5.3.1 20160413] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> a = exec('print(42)')
  File "<stdin>", line 1
    a = exec('print(42)')
           ^
SyntaxError: invalid syntax

(which wouldn't be useful in Python 3 either, as exec always returns None), or pass a reference to exec:

>>> call_later(exec, 'print(42)', delay=1000)
  File "<stdin>", line 1
    call_later(exec, 'print(42)', delay=1000)
                  ^
SyntaxError: invalid syntax

Which a pattern that someone might actually have used, though unlikely;

Or use it in a list comprehension:

>>> [exec(i) for i in ['print(42)', 'print(foo)']
  File "<stdin>", line 1
    [exec(i) for i in ['print(42)', 'print(foo)']
        ^
SyntaxError: invalid syntax

which is abuse of list comprehensions (use a for loop instead!).

href="file://" doesn't work

The reason your URL is being rewritten to file///K:/AmberCRO%20SOP/2011-07-05/SOP-SOP-3.0.pdf is because you specified http://file://

The http:// at the beginning is the protocol being used, and your browser is stripping out the second colon (:) because it is invalid.

Note

If you link to something like

<a href="file:///K:/yourfile.pdf">yourfile.pdf</a>

The above represents a link to a file called k:/yourfile.pdf on the k: drive on the machine on which you are viewing the URL.

You can do this, for example the below creates a link to C:\temp\test.pdf

<a href="file:///C:/Temp/test.pdf">test.pdf</a>

By specifying file:// you are indicating that this is a local resource. This resource is NOT on the internet.

Most people do not have a K:/ drive.

But, if this is what you are trying to achieve, that's fine, but this is not how a "typical" link on a web page works, and you shouldn't being doing this unless everyone who is going to access your link has access to the (same?) K:/drive (this might be the case with a shared network drive).

You could try

<a href="file:///K:/AmberCRO-SOP/2011-07-05/SOP-SOP-3.0.pdf">test.pdf</a>
<a href="AmberCRO-SOP/2011-07-05/SOP-SOP-3.0.pdf">test.pdf</a>
<a href="2011-07-05/SOP-SOP-3.0.pdf">test.pdf</a>

Note that http://file:///K:/AmberCRO%20SOP/2011-07-05/SOP-SOP-3.0.pdf is a malformed

need to test if sql query was successful

if you're not using the -> format, you can do this:

$a = "SQL command...";
if ($b = mysqli_query($con,$a)) {
  // results was successful
} else {
  // result was not successful
}

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

The actual problem of this error has nothing to do with file_get_content, the problem is the requested url if the url is not throwing content of the page and redirecting the request to some where else file_get_content says "Failed to open stream", just before file_get_contents check whether the url is working and not redirecting, here is the code:

function checkRedirect404($url) {

$ch = curl_init();

curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

    curl_setopt($ch, CURLOPT_URL, $url);
    $out = curl_exec($ch);

    // line endings is the wonkiest piece of this whole thing
    $out = str_replace("\r", "", $out);

    // only look at the headers
    $headers_end = strpos($out, "\n\n");
    if( $headers_end !== false ) { 
        $out = substr($out, 0, $headers_end);
    }   

    $headers = explode("\n", $out);
    foreach($headers as $header) {
        if( substr($header, 0, 10) == "Location: " ) { 
            $target = substr($header, 10);

            //echo "Redirects: $target<br>";

            return true;
        }   
    }   

    return false;

}

Hide Text with CSS, Best Practice?

Add .hide-text class to your span that has the text

.hide-text{
display:none;
 }

or make the text transparent

.hide-text{
 color:rgba(0,0,0,0);
 }

use according to your use case.

Escape dot in a regex range

On this web page, I see that:

"Remember that the dot is not a metacharacter inside a character class, so we do not need to escape it with a backslash."

So I guess the escaping of it is unnecessary...

How can I compare time in SQL Server?

I believe you want to use DATEPART('hour', datetime).

Reference is here:

http://msdn.microsoft.com/en-us/library/ms174420.aspx

How to get unique values in an array

I have tried this problem in pure JS. I have followed following steps 1. Sort the given array, 2. loop through the sorted array, 3. Verify previous value and next value with current value

// JS
var inpArr = [1, 5, 5, 4, 3, 3, 2, 2, 2,2, 100, 100, -1];

//sort the given array
inpArr.sort(function(a, b){
    return a-b;
});

var finalArr = [];
//loop through the inpArr
for(var i=0; i<inpArr.length; i++){
    //check previous and next value 
  if(inpArr[i-1]!=inpArr[i] && inpArr[i] != inpArr[i+1]){
        finalArr.push(inpArr[i]);
  }
}
console.log(finalArr);

Demo

How to add jQuery in JS file

After lots of research, I solve this issue with hint from ofir_aghai answer about script load event.

Basically we need to use $ for jQuery code, but we can't use it till jQuery is loaded. I used document.createElement() to add a script for jQuery, but the issue is that it takes time to load while the next statement in JavaScript using $ fails. So, I used the below solution.

myscript.js is having code which uses jQuery main.js is used to load both jquery.min.js and myscript.js files making sure that jQuery is loaded.

main.js code

window.load = loadJQueryFile();
var heads = document.getElementsByTagName('head');

function loadJQueryFile(){
    var jqueryScript=document.createElement('script');
    jqueryScript.setAttribute("type","text/javascript");
    jqueryScript.setAttribute("src", "/js/jquery.min.js");

    jqueryScript.onreadystatechange = handler;
    jqueryScript.onload = handler;  
    heads[0].appendChild(jqueryScript);
}

function handler(){
    var myScriptFile=document.createElement('script');
    myScriptFile.setAttribute("type","text/javascript");
    myScriptFile.setAttribute("src", "myscript.js");
    heads[0].appendChild(myScriptFile);
 }

This way it worked. Using loadJQueryFile() from myscript.js didn't work. It immediately goes to the next statement which uses $.

Multiple Errors Installing Visual Studio 2015 Community Edition

I just found similar issue and I tried to fix it by uninstall, and reinstall several time both using the web installer and the ISO but it cannot solved the problem. Finally, I have fixed it by reset the PC and installing Visual Studio 2015 again by using the ISO.

Expand a random range from 1–5 to 1–7

A constant time solution that produces approximately uniform distribution. The trick is 625 happens to be cleanly divisible by 7 and you can get uniform distributions as you build up to that range.

Edit: My bad, I miscalculated, but instead of pulling it I'll leave it in case someone finds it useful/entertaining. It does actually work after all... :)

int rand5()
{
    return (rand() % 5) + 1;
}

int rand25()
{ 
    return (5 * (rand5() - 1) + rand5());
}

int rand625()
{
    return (25 * (rand25() - 1) + rand25());
}

int rand7()
{
    return ((625 * (rand625() - 1) + rand625()) - 1) % 7 + 1;
}

Expand Python Search Path to Other Source

The easiest way I find is to create a file "any_name.pth" and put it in your folder "\Lib\site-packages". You should find that folder wherever python is installed.

In that file, put a list of directories where you want to keep modules for importing. For instance, make a line in that file like this:

C:\Users\example...\example

You will be able to tell it works by running this in python:

import sys
for line in sys: print line

You will see your directory printed out, amongst others from where you can also import. Now you can import a "mymodule.py" file that sits in that directory as easily as:

import mymodule

This will not import subfolders. For that you could imagine creating a python script to create a .pth file containing all sub folders of a folder you define. Have it run at startup perhaps.

How can I upload fresh code at github?

git init
git add .
git commit -m "Initial commit"

After this, make a new GitHub repository and follow on-screen instructions.

How to use a client certificate to authenticate and authorize in a Web API

Tracing helped me find what the problem was (Thank you Fabian for that suggestion). I found with further testing that I could get the client certificate to work on another server (Windows Server 2012). I was testing this on my development machine (Window 7) so I could debug this process. So by comparing the trace to an IIS Server that worked and one that did not I was able to pinpoint the relevant lines in the trace log. Here is a portion of a log where the client certificate worked. This is the setup right before the send

System.Net Information: 0 : [17444] InitializeSecurityContext(In-Buffers count=2, Out-Buffer length=0, returned code=CredentialsNeeded).
System.Net Information: 0 : [17444] SecureChannel#54718731 - We have user-provided certificates. The server has not specified any issuers, so try all the certificates.
System.Net Information: 0 : [17444] SecureChannel#54718731 - Selected certificate:

Here is what the trace log looked like on the machine where the client certificate failed.

System.Net Information: 0 : [19616] InitializeSecurityContext(In-Buffers count=2, Out-Buffer length=0, returned code=CredentialsNeeded).
System.Net Information: 0 : [19616] SecureChannel#54718731 - We have user-provided certificates. The server has specified 137 issuer(s). Looking for certificates that match any of the issuers.
System.Net Information: 0 : [19616] SecureChannel#54718731 - Left with 0 client certificates to choose from.
System.Net Information: 0 : [19616] Using the cached credential handle.

Focusing on the line that indicated the server specified 137 issuers I found this Q&A that seemed similar to my issue. The solution for me was not the one marked as an answer since my certificate was in the trusted root. The answer is the one under it where you update the registry. I just added the value to the registry key.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL

Value name: SendTrustedIssuerList Value type: REG_DWORD Value data: 0 (False)

After adding this value to the registry it started to work on my Windows 7 machine. This appears to be a Windows 7 issue.

Passing html values into javascript functions

Try: if(parseInt(order)>0){....

String to HtmlDocument

you could get a htmldocument by:

 System.Net.WebClient wc = new System.Net.WebClient();

 System.IO.Stream stream = wc.OpenRead(url);
 System.IO.StreamReader reader = new System.IO.StreamReader(stream);
 string s = reader.ReadToEnd();

 HtmlDocument doc = new HtmlDocument();
 doc.LoadHtml(s);

so you have getbiyid and getbyname ... but any further you'd better of with
HTML Agility Pack as suggested . f.e you can do: doc.DocumentNode.SelectNodes(xpathselector) or regex to parse the doc ..

btw: why not regex ? . its soo cool if you can use it right... but xpath is also very mighty ... so "choose your poison"

cu

How can you dynamically create variables via a while loop?

Use the exec() method. For example, say you have a dictionary and you want to turn each key into a variable with its original dictionary value can do the following.

Python 2

>>> c = {"one": 1, "two": 2}
>>> for k,v in c.iteritems():
...    exec("%s=%s" % (k,v))

>>> one
1
>>> two
2

Python 3

>>> c = {"one": 1, "two": 2}
>>> for k,v in c.items():
...    exec("%s=%s" % (k,v))

>>> one
1
>>> two
2

How to exclude records with certain values in sql select

You can use EXCEPT syntax, for example:

SELECT var FROM table1
EXCEPT
SELECT var FROM table2

Change directory in PowerShell

Multiple posted answer here, but probably this can help who is newly using PowerShell

enter image description here

SO if any space is there in your directory path do not forgot to add double inverted commas "".

Converting bool to text in C++

C++20 std::format("{}"

https://en.cppreference.com/w/cpp/utility/format/formatter#Standard_format_specification claims that the default output format will be the string by default:

auto s6 = std::format("{:6}", true);  // value of s6 is "true  "

and:

The available bool presentation types are:

  • none, s: Copies textual representation (true or false, or the locale-specific form) to the output.
  • b, B, c, d, o, x, X: Uses integer presentation types with the value static_cast(value).

Related: std::string formatting like sprintf

Unable to convert MySQL date/time value to System.DateTime

I also faced the same problem, and get the columns name and its types. Then cast(col_Name as Char) from table name. From this way i get the problem as '0000-00-00 00:00:00' then I Update as valid date and time the error gets away for my case.

What's the best free C++ profiler for Windows?

I used Luke Stackwalker and it did the job for my Visual Studio project.

Other interesting projects are:

How to change the size of the font of a JLabel to take the maximum size

Just wanted to point out that the accepted answer has a couple of limitations (which I discovered when I tried to use it)

  1. As written, it actually keeps recalculating the font size based on a ratio of the previous font size... thus after just a couple of calls it has rendered the font size as much too large. (eg Start with 12 point as your DESIGNED Font, expand the label by just 1 pixel, and the published code will calculate the Font size as 12 * (say) 1.2 (ratio of field space to text) = 14.4 or 14 point font. 1 more Pixel and call and you are at 16 point !).

It is thus not suitable (without adaptation) for use in a repeated-call setting (eg a ComponentResizedListener, or a custom/modified LayoutManager).

The listed code effectively assumes a starting size of 10 pt but refers to the current font size and is thus suitable for calling once (to set the size of the font when the label is created). It would work better in a multi-call environment if it did int newFontSize = (int) (widthRatio * 10); rather than int newFontSize = (int)(labelFont.getSize() * widthRatio);

  1. Because it uses new Font(labelFont.getName(), Font.PLAIN, fontSizeToUse)) to generate the new font, there is no support for Bolding, Italic or Color etc from the original font in the updated font. It would be more flexible if it made use of labelFont.deriveFont instead.

  2. The solution does not provide support for HTML label Text. (I know that was probably not ever an intended outcome of the answer code offered, but as I had an HTML-text JLabel on my JPanel I formally discovered the limitation. The FontMetrics.stringWidth() calculates the text length as inclusive of the width of the html tags - ie as simply more text)

I recommend looking at the answer to this SO question where trashgod's answer points to a number of different answers (including this one) to an almost identical question. On that page I will provide an additional answer that speeds up one of the other answers by a factor of 30-100.

Convert string to float?

Use Float.valueOf(String) to do the conversion.

The difference between valueOf() and parseFloat() is only the return. Use the former if you want a Float (object) and the latter if you want the float number.

How to detect a remote side socket close?

The method Socket.Available will immediately throw a SocketException if the remote system has disconnected/closed the connection.

Are dictionaries ordered in Python 3.6+?

To fully answer this question in 2020, let me quote several statements from official Python docs:

Changed in version 3.7: Dictionary order is guaranteed to be insertion order. This behavior was an implementation detail of CPython from 3.6.

Changed in version 3.7: Dictionary order is guaranteed to be insertion order.

Changed in version 3.8: Dictionaries are now reversible.

Dictionaries and dictionary views are reversible.

A statement regarding OrderedDict vs Dict:

Ordered dictionaries are just like regular dictionaries but have some extra capabilities relating to ordering operations. They have become less important now that the built-in dict class gained the ability to remember insertion order (this new behavior became guaranteed in Python 3.7).

SET NOCOUNT ON usage

  • SET NOCOUNT ON- It will show "Command(s) completed successfully".
  • SET NOCOUNT OFF- it will show "(No. Of row(s) affected)".

mysqldump data only

Would suggest using the following snippet. Works fine even with huge tables (otherwise you'd open dump in editor and strip unneeded stuff, right? ;)

mysqldump --no-create-info --skip-triggers --extended-insert --lock-tables --quick DB TABLE > dump.sql

At least mysql 5.x required, but who runs old stuff nowadays.. :)

AttributeError: 'list' object has no attribute 'encode'

You need to do encode on tmp[0], not on tmp.

tmp is not a string. It contains a (Unicode) string.

Try running type(tmp) and print dir(tmp) to see it for yourself.

postgresql - replace all instances of a string within text field

The Regular Expression Way

If you need stricter replacement matching, PostgreSQL's regexp_replace function can match using POSIX regular expression patterns. It has the syntax regexp_replace(source, pattern, replacement [, flags ]).

I will use flags i and g for case-insensitive and global matching, respectively. I will also use \m and \M to match the beginning and the end of a word, respectively.

There are usually quite a few gotchas when performing regex replacment. Let's see how easy it is to replace a cat with a dog.

SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat', 'dog');
-->                    Cat bobdog cat cats catfish

SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat', 'dog', 'i');
-->                    dog bobcat cat cats catfish

SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat', 'dog', 'g');
-->                    Cat bobdog dog dogs dogfish

SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat', 'dog', 'gi');
-->                    dog bobdog dog dogs dogfish

SELECT regexp_replace('Cat bobcat cat cats catfish', '\mcat', 'dog', 'gi');
-->                    dog bobcat dog dogs dogfish

SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat\M', 'dog', 'gi');
-->                    dog bobdog dog cats catfish

SELECT regexp_replace('Cat bobcat cat cats catfish', '\mcat\M', 'dog', 'gi');
-->                    dog bobcat dog cats catfish

SELECT regexp_replace('Cat bobcat cat cats catfish', '\mcat(s?)\M', 'dog\1', 'gi');
-->                    dog bobcat dog dogs catfish

Even after all of that, there is at least one unresolved condition. For example, sentences that begin with "Cat" will be replaced with lower-case "dog" which break sentence capitalization.

Check out the current PostgreSQL pattern matching docs for all the details.

Update entire column with replacement text

Given my examples, maybe the safest option would be:

UPDATE table SET field = regexp_replace(field, '\mcat\M', 'dog', 'gi');

Show Youtube video source into HTML5 video tag?

how about doing it the way hooktube does it? they don't actually use the video URL for the html5 element, but the google video redirector url that calls upon that video. check out here's how they present some despacito random video...

<video id="player-obj" controls="" src="https://redirector.googlevideo.com/videoplayback?ratebypass=yes&amp;mt=1510077993----SKIPPED----amp;utmg=ytap1,,hd720"><source>Your browser does not support HTML5 video.</video>

the code is for the following video page https://hooktube.com/watch?v=72UO0v5ESUo

youtube to mp3 on the other hand has turned into extremely monetized monster that returns now download.html on half of video download requests... annoying...

the 2 links in this answer are to my personal experiences with both resources. how hooktube is nice and fresh and actually helps avoid censorship and geo restrictions.. check it out, it's pretty cool. and youtubeinmp4 is a popup monster now known as ConvertInMp4...

How to extract base URL from a string in JavaScript?

This works:

location.href.split(location.pathname)[0];

How to identify if a webpage is being loaded inside an iframe or directly into the browser window?

Browsers can block access to window.top due to same origin policy. IE bugs also take place. Here's the working code:

function inIframe () {
    try {
        return window.self !== window.top;
    } catch (e) {
        return true;
    }
}

top and self are both window objects (along with parent), so you're seeing if your window is the top window.

Specifying ssh key in ansible playbook file

The variable name you're looking for is ansible_ssh_private_key_file.

You should set it at 'vars' level:

  • in the inventory file:

    myHost ansible_ssh_private_key_file=~/.ssh/mykey1.pem
    myOtherHost ansible_ssh_private_key_file=~/.ssh/mykey2.pem
    
  • in the host_vars:

    # hosts_vars/myHost.yml
    ansible_ssh_private_key_file: ~/.ssh/mykey1.pem
    
    # hosts_vars/myOtherHost.yml
    ansible_ssh_private_key_file: ~/.ssh/mykey2.pem
    
  • in a group_vars file if you use the same key for a group of hosts

  • in the vars section of your play:

    - hosts: myHost
      remote_user: ubuntu
      vars_files:
        - vars.yml
      vars:
        ansible_ssh_private_key_file: "{{ key1 }}"
      tasks:
        - name: Echo a hello message
          command: echo hello
    

Inventory documentation

Cannot open include file: 'unistd.h': No such file or directory

If you're using ZLib in your project, then you need to find :

#if 1

in zconf.h and replace(uncomment) it with :

#if HAVE_UNISTD_H /* ...the rest of the line

If it isn't ZLib I guess you should find some alternative way to do this. GL.

The breakpoint will not currently be hit. No symbols have been loaded for this document in a Silverlight application

I took the easiest path, actually in my multiple projects solution, including one class library, I had an issue with a .dll file created by that class library project which was not allowing me to have breakpoints while executing, because it was not building for some reason, I separately build that project and referenced it's output .dll and now the breakpoints are functional

Not sure, maybe this helps you; if not you then someone new like me just because it worked for me:)

How to find available directory objects on Oracle 11g system?

The ALL_DIRECTORIES data dictionary view will have information about all the directories that you have access to. That includes the operating system path

SELECT owner, directory_name, directory_path
  FROM all_directories

Java 8 optional: ifPresent return object orElseThrow exception

Use the map-function instead. It transforms the value inside the optional.

Like this:

private String getStringIfObjectIsPresent(Optional<Object> object) {
    return object.map(() -> {
        String result = "result";
        //some logic with result and return it
        return result;
    }).orElseThrow(MyCustomException::new);
}

socket programming multiple client to one server

I guess the problem is that you need to start a separate thread for each connection and call serverSocket.accept() in a loop to accept more than one connection.

It is not a problem to have more than one connection on the same port.

Best way to access a control on another form in Windows Forms?

You can

  1. Create a public method with needed parameter on child form and call it from parent form (with valid cast)
  2. Create a public property on child form and access it from parent form (with valid cast)
  3. Create another constructor on child form for setting form's initialization parameters
  4. Create custom events and/or use (static) classes

Best practice would be #4 if you are using non-modal forms.

Shell script to get the process ID on Linux

Using grep on the results of ps is a bad idea in a script, since some proportion of the time it will also match the grep process you've just invoked. The command pgrep avoids this problem, so if you need to know the process ID, that's a better option. (Note that, of course, there may be many processes matched.)

However, in your example, you could just use the similar command pkill to kill all matching processes:

pkill ruby

Incidentally, you should be aware that using -9 is overkill (ho ho) in almost every case - there's some useful advice about that in the text of the "Useless Use of kill -9 form letter ":

No no no. Don't use kill -9.

It doesn't give the process a chance to cleanly:

  1. shut down socket connections
  2. clean up temp files
  3. inform its children that it is going away
  4. reset its terminal characteristics

and so on and so on and so on.

Generally, send 15, and wait a second or two, and if that doesn't work, send 2, and if that doesn't work, send 1. If that doesn't, REMOVE THE BINARY because the program is badly behaved!

Don't use kill -9. Don't bring out the combine harvester just to tidy up the flower pot.

ASP.NET MVC Razor: How to render a Razor Partial View's HTML inside the controller action

@Html.Partial("nameOfPartial", Model)

Update

protected string RenderPartialViewToString(string viewName, object model)
{
    if (string.IsNullOrEmpty(viewName))
        viewName = ControllerContext.RouteData.GetRequiredString("action");

    ViewData.Model = model;

    using (StringWriter sw = new StringWriter()) {
        ViewEngineResult viewResult = ViewEngines.Engines.FindPartialView(ControllerContext, viewName);
        ViewContext viewContext = new ViewContext(ControllerContext, viewResult.View, ViewData, TempData, sw);
        viewResult.View.Render(viewContext, sw);

        return sw.GetStringBuilder().ToString();
    }
}

For Restful API, can GET method use json data?

To answer your question, yes you may pass JSON in the URI as part of a GET request (provided you URL-encode). However, considering your reason for doing this is due to the length of the URI, using JSON will be self-defeating (introducing more characters than required).

I suggest you send your parameters in body of a POST request, either in regular CGI style (param1=val1&param2=val2) or JSON (parsed by your API upon receipt)

Handling exceptions from Java ExecutorService tasks

Another solution would be to use the ManagedTask and ManagedTaskListener.

You need a Callable or Runnable which implements the interface ManagedTask.

The method getManagedTaskListener returns the instance you want.

public ManagedTaskListener getManagedTaskListener() {

And you implement in ManagedTaskListener the taskDone method:

@Override
public void taskDone(Future<?> future, ManagedExecutorService executor, Object task, Throwable exception) {
    if (exception != null) {
        LOGGER.log(Level.SEVERE, exception.getMessage());
    }
}

More details about managed task lifecycle and listener.

How to change column datatype in SQL database without losing data

Replace datatype without losing data

alter table tablename modify columnn  newdatatype(size);

Which is better, return value or out parameter?

I suspect I'm not going to get a look-in on this question, but I am a very experienced programmer, and I hope some of the more open-minded readers will pay attention.

I believe that it suits object-oriented programming languages better for their value-returning procedures (VRPs) to be deterministic and pure.

'VRP' is the modern academic name for a function that is called as part of an expression, and has a return value that notionally replaces the call during evaluation of the expression. E.g. in a statement such as x = 1 + f(y) the function f is serving as a VRP.

'Deterministic' means that the result of the function depends only on the values of its parameters. If you call it again with the same parameter values, you are certain to get the same result.

'Pure' means no side-effects: calling the function does nothing except computing the result. This can be interpreted to mean no important side-effects, in practice, so if the VRP outputs a debugging message every time it is called, for example, that can probably be ignored.

Thus, if, in C#, your function is not deterministic and pure, I say you should make it a void function (in other words, not a VRP), and any value it needs to return should be returned in either an out or a ref parameter.

For example, if you have a function to delete some rows from a database table, and you want it to return the number of rows it deleted, you should declare it something like this:

public void DeleteBasketItems(BasketItemCategory category, out int count);

If you sometimes want to call this function but not get the count, you could always declare an overloading.

You might want to know why this style suits object-oriented programming better. Broadly, it fits into a style of programming that could be (a little imprecisely) termed 'procedural programming', and it is a procedural programming style that fits object-oriented programming better.

Why? The classical model of objects is that they have properties (aka attributes), and you interrogate and manipulate the object (mainly) through reading and updating those properties. A procedural programming style tends to make it easier to do this, because you can execute arbitrary code in between operations that get and set properties.

The downside of procedural programming is that, because you can execute arbitrary code all over the place, you can get some very obtuse and bug-vulnerable interactions via global variables and side-effects.

So, quite simply, it is good practice to signal to someone reading your code that a function could have side-effects by making it non-value returning.

Maven Install on Mac OS X

% sudo port selfupdate; 
% sudo port upgrade outdated;
% sudo port install maven3;
% sudo port select --set maven maven3;

— add following to .zshenv -- start using zsh if you dont —
set -a
[[ -d /opt/local/share/java/maven3 ]] &&
    M3_HOME=/opt/local/share/java/maven3 &&
    M2_HOME=/opt/local/share/java/maven3 &&
    MAVEN_OPTS="-Xmx1024m" &&
    M2=${M2_HOME}/bin
set +a

How to find minimum value from vector?

template <class ForwardIterator>
ForwardIterator min_element ( ForwardIterator first, ForwardIterator last )
{
    ForwardIterator lowest = first;
    if (first == last) return last;
    while (++first != last)
    if (*first < *lowest) 
        lowest = first;
    return lowest;
}

ssh: connect to host github.com port 22: Connection timed out

Restart computer solved it for me.
Git version: 2.27.0.windows.1
OS version: Windows 10 v1909

Get IFrame's document, from JavaScript in main document

In case you get a cross-domain error:

If you have control over the content of the iframe - that is, if it is merely loaded in a cross-origin setup such as on Amazon Mechanical Turk - you can circumvent this problem with the <body onload='my_func(my_arg)'> attribute for the inner html.

For example, for the inner html, use the this html parameter (yes - this is defined and it refers to the parent window of the inner body element):

<body onload='changeForm(this)'>

In the inner html :

    function changeForm(window) {
        console.log('inner window loaded: do whatever you want with the inner html');
        window.document.getElementById('mturk_form').style.display = 'none';
    </script>

python: changing row index of pandas data frame

you can do

followers_df.index = range(20)

How to configure the web.config to allow requests of any length

Something else to check: if your site is using MVC, this can happen if you added [Authorize] to your login controller class. It can't access the login method because it's not authorized so it redirects to the login method --> boom.

Unable to start Service Intent

I've found the same problem. I lost almost a day trying to start a service from OnClickListener method - outside the onCreate and after 1 day, I still failed!!!! Very frustrating! I was looking at the sample example RemoteServiceController. Theirs works, but my implementation does not work!

The only way that was working for me, was from inside onCreate method. None of the other variants worked and believe me I've tried them all.

Conclusion:

  • If you put your service class in different package than the mainActivity, I'll get all kind of errors
  • Also the one "/" couldn't find path to the service, tried starting with Intent(package,className) and nothing , also other type of Intent starting

  • I moved the service class in the same package of the activity Final form that works

  • Hopefully this helps someone by defining the listerners onClick inside the onCreate method like this:

    public void onCreate() {
    //some code......
        Button btnStartSrv  = (Button)findViewById(R.id.btnStartService);
        Button btnStopSrv  = (Button)findViewById(R.id.btnStopService);
    
        btnStartSrv.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                startService(new Intent("RM_SRV_AIDL"));
            }
        });
    
        btnStopSrv.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                stopService(new Intent("RM_SRV_AIDL"));
            }
        });
    
    } // end onCreate
    

Also very important for the Manifest file, be sure that service is child of application:

<application ... >
    <activity ... >
     ...
    </activity>
    <service
        android:name="com.mainActivity.MyRemoteGPSService"
        android:label="GPSService"
        android:process=":remote">

        <intent-filter>
             <action android:name="RM_SRV_AIDL" />
        </intent-filter>
    </service>
</application>

Getting a UnhandledPromiseRejectionWarning when testing using mocha/chai

I faced this issue:

(node:1131004) UnhandledPromiseRejectionWarning: Unhandled promise rejection (re jection id: 1): TypeError: res.json is not a function (node:1131004) DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.j s process with a non-zero exit code.

It was my mistake, I was replacing res object in then(function(res), so changed res to result and now it is working.

Wrong

module.exports.update = function(req, res){
        return Services.User.update(req.body)
                .then(function(res){//issue was here, res overwrite
                    return res.json(res);
                }, function(error){
                    return res.json({error:error.message});
                }).catch(function () {
                   console.log("Promise Rejected");
              });

Correction

module.exports.update = function(req, res){
        return Services.User.update(req.body)
                .then(function(result){//res replaced with result
                    return res.json(result);
                }, function(error){
                    return res.json({error:error.message});
                }).catch(function () {
                   console.log("Promise Rejected");
              });

Service code:

function update(data){
   var id = new require('mongodb').ObjectID(data._id);
        userData = {
                    name:data.name,
                    email:data.email,
                    phone: data.phone
                };
 return collection.findAndModify(
          {_id:id}, // query
          [['_id','asc']],  // sort order
          {$set: userData}, // replacement
          { "new": true }
          ).then(function(doc) {
                if(!doc)
                    throw new Error('Record not updated.');
                return doc.value;   
          });
    }

module.exports = {
        update:update
}

C# Version Of SQL LIKE

Simply .Contains() would do the work for you.

"Example String".Contains("amp");   //like '%amp%'

This would return true, and performing a select on it would return the desired output.

Get the element with the highest occurrence in an array

Here is my way to do it so just using .filter.

_x000D_
_x000D_
var arr = ['pear', 'apple', 'orange', 'apple'];

function dup(arrr) {
    let max = { item: 0, count: 0 };
    for (let i = 0; i < arrr.length; i++) {
        let arrOccurences = arrr.filter(item => { return item === arrr[i] }).length;
        if (arrOccurences > max.count) {
            max = { item: arrr[i], count: arrr.filter(item => { return item === arrr[i] }).length };
        }
    }
    return max.item;
}
console.log(dup(arr));
_x000D_
_x000D_
_x000D_

Safely casting long to int in Java

Java integer types are represented as signed. With an input between 231 and 232 (or -231 and -232) the cast would succeed but your test would fail.

What to check for is whether all of the high bits of the long are all the same:

public static final long LONG_HIGH_BITS = 0xFFFFFFFF80000000L;
public static int safeLongToInt(long l) {
    if ((l & LONG_HIGH_BITS) == 0 || (l & LONG_HIGH_BITS) == LONG_HIGH_BITS) {
        return (int) l;
    } else {
        throw new IllegalArgumentException("...");
    }
}

How to get rid of punctuation using NLTK tokenizer?

I use this code to remove punctuation:

import nltk
def getTerms(sentences):
    tokens = nltk.word_tokenize(sentences)
    words = [w.lower() for w in tokens if w.isalnum()]
    print tokens
    print words

getTerms("hh, hh3h. wo shi 2 4 A . fdffdf. A&&B ")

And If you want to check whether a token is a valid English word or not, you may need PyEnchant

Tutorial:

 import enchant
 d = enchant.Dict("en_US")
 d.check("Hello")
 d.check("Helo")
 d.suggest("Helo")

How to reset Jenkins security settings from the command line?

The simplest solution is to completely disable security - change true to false in /var/lib/jenkins/config.xml file.

<useSecurity>true</useSecurity>

Then just restart Jenkins, by

sudo service jenkins restart

And then go to admin panel and set everything once again.

If you in case are running your Jenkins inside k8s pod from a docker, which is my case and can not run service command, then you can just restart Jenkins by deleting the pod:

kubectl delete pod <jenkins-pod-name>

Once the command was issued, the k8s will terminate the old pod and start a new one.

Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array

In this post was useful for duplication check if u are using Jquery.

How to find the duplicates in an array using jquery

var unique_values = {}; var list_of_values = []; $('input[name$="recordset"]').     each(function(item) {          if ( ! unique_values[item.value] ) {             unique_values[item.value] = true;             list_of_values.push(item.value);         } else {             // We have duplicate values!         }     });

Barcode scanner for mobile phone for Website in form

There's a JS QrCode scanner, that works on mobile sites with a camera:

https://github.com/LazarSoft/jsqrcode

I have worked with it for one of my project and it works pretty good !

Code coverage for Jest built on top of Jasmine

I had the same issue and I fixed it as below.

  1. install yarn npm install --save-dev yarn
  2. install jest-cli npm install --save-dev jest-cli
  3. add this to the package.json "jest-coverage": "yarn run jest -- --coverage"

After you write the tests, run the command npm run jest-coverage. This will create a coverage folder in the root directory. /coverage/icov-report/index.html has the HTML view of the code coverage.

Iterating through a range of dates in Python

> pip install DateTimeRange

from datetimerange import DateTimeRange

def dateRange(start, end, step):
        rangeList = []
        time_range = DateTimeRange(start, end)
        for value in time_range.range(datetime.timedelta(days=step)):
            rangeList.append(value.strftime('%m/%d/%Y'))
        return rangeList

    dateRange("2018-09-07", "2018-12-25", 7)  

    Out[92]: 
    ['09/07/2018',
     '09/14/2018',
     '09/21/2018',
     '09/28/2018',
     '10/05/2018',
     '10/12/2018',
     '10/19/2018',
     '10/26/2018',
     '11/02/2018',
     '11/09/2018',
     '11/16/2018',
     '11/23/2018',
     '11/30/2018',
     '12/07/2018',
     '12/14/2018',
     '12/21/2018']

Bootstrap center heading

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

.text-center {
  text-align: center;
}

bootstrap has added three css classes for text align.

How to empty a list in C#?

It's really easy:

myList.Clear();

How do I set environment variables from Java?

Like most people who have found this thread, I was writing some unit tests and needed to modify the environment variables to set the correct conditions for the test to run. However, I found the most upvoted answers had some issues and/or were very cryptic or overly complicated. Hopefully this will help others to sort out the solution more quickly.

First off, I finally found @Hubert Grzeskowiak's solution to be the simplest and it worked for me. I wish I would have come to that one first. It's based on @Edward Campbell's answer, but without the complicating for loop search.

However, I started with @pushy's solution, which got the most upvotes. It is a combo of @anonymous and @Edward Campbell's. @pushy claims both approaches are needed to cover both Linux and Windows environments. I'm running under OS X and find that both work (once an issue with @anonymous approach is fixed). As others have noted, this solution works most of the time, but not all.

I think the source of most of the confusion comes from @anonymous's solution operating on the 'theEnvironment' field. Looking at the definition of the ProcessEnvironment structure, 'theEnvironment' is not a Map< String, String > but rather it is a Map< Variable, Value >. Clearing the map works fine, but the putAll operation rebuilds the map a Map< String, String >, which potentially causes problems when subsequent operations operate on the data structure using the normal API that expects Map< Variable, Value >. Also, accessing/removing individual elements is a problem. The solution is to access 'theEnvironment' indirectly through 'theUnmodifiableEnvironment'. But since this is a type UnmodifiableMap the access must be done through the private variable 'm' of the UnmodifiableMap type. See getModifiableEnvironmentMap2 in code below.

In my case I needed to remove some of the environment variables for my test (the others should be unchanged). Then I wanted to restore the environment variables to their prior state after the test. The routines below make that straight forward to do. I tested both versions of getModifiableEnvironmentMap on OS X, and both work equivalently. Though based on comments in this thread, one may be a better choice than the other depending on the environment.

Note: I did not include access to the 'theCaseInsensitiveEnvironmentField' since that seems to be Windows specific and I had no way to test it, but adding it should be straight forward.

private Map<String, String> getModifiableEnvironmentMap() {
    try {
        Map<String,String> unmodifiableEnv = System.getenv();
        Class<?> cl = unmodifiableEnv.getClass();
        Field field = cl.getDeclaredField("m");
        field.setAccessible(true);
        Map<String,String> modifiableEnv = (Map<String,String>) field.get(unmodifiableEnv);
        return modifiableEnv;
    } catch(Exception e) {
        throw new RuntimeException("Unable to access writable environment variable map.");
    }
}

private Map<String, String> getModifiableEnvironmentMap2() {
    try {
        Class<?> processEnvironmentClass = Class.forName("java.lang.ProcessEnvironment");
        Field theUnmodifiableEnvironmentField = processEnvironmentClass.getDeclaredField("theUnmodifiableEnvironment");
        theUnmodifiableEnvironmentField.setAccessible(true);
        Map<String,String> theUnmodifiableEnvironment = (Map<String,String>)theUnmodifiableEnvironmentField.get(null);

        Class<?> theUnmodifiableEnvironmentClass = theUnmodifiableEnvironment.getClass();
        Field theModifiableEnvField = theUnmodifiableEnvironmentClass.getDeclaredField("m");
        theModifiableEnvField.setAccessible(true);
        Map<String,String> modifiableEnv = (Map<String,String>) theModifiableEnvField.get(theUnmodifiableEnvironment);
        return modifiableEnv;
    } catch(Exception e) {
        throw new RuntimeException("Unable to access writable environment variable map.");
    }
}

private Map<String, String> clearEnvironmentVars(String[] keys) {

    Map<String,String> modifiableEnv = getModifiableEnvironmentMap();

    HashMap<String, String> savedVals = new HashMap<String, String>();

    for(String k : keys) {
        String val = modifiableEnv.remove(k);
        if (val != null) { savedVals.put(k, val); }
    }
    return savedVals;
}

private void setEnvironmentVars(Map<String, String> varMap) {
    getModifiableEnvironmentMap().putAll(varMap);   
}

@Test
public void myTest() {
    String[] keys = { "key1", "key2", "key3" };
    Map<String, String> savedVars = clearEnvironmentVars(keys);

    // do test

    setEnvironmentVars(savedVars);
}

How to pass values between Fragments

Communicating between fragments is fairly complicated (I find the listeners concept a little challenging to implement).

It is common to use a 'Event Bus" to abstract these communications. This is a 3rd party library that takes care of this communication for you.

'Otto' is one that is used often to do this, and might be worth looking into: http://square.github.io/otto/

Convert DataTable to IEnumerable<T>

        PagedDataSource objPage = new PagedDataSource();

        DataView dataView = listData.DefaultView;
        objPage.AllowPaging = true;
        objPage.DataSource = dataView;
        objPage.PageSize = PageSize;

        TotalPages = objPage.PageCount;

        objPage.CurrentPageIndex = CurrentPage - 1;

        //Convert PagedDataSource to DataTable
        System.Collections.IEnumerator pagedData = objPage.GetEnumerator();

        DataTable filteredData = new DataTable();
        bool flagToCopyDTStruct = false;
        while (pagedData.MoveNext())
        {
            DataRowView rowView = (DataRowView)pagedData.Current;
            if (!flagToCopyDTStruct)
            {
                filteredData = rowView.Row.Table.Clone();
                flagToCopyDTStruct = true;
            }
            filteredData.LoadDataRow(rowView.Row.ItemArray, true);
        }

        //Here is your filtered DataTable
        return filterData; 

Trim a string in C

You can use the standard isspace() function in ctype.h to achieve this. Simply compare the beginning and end characters of your character array until both ends no longer have spaces.

"spaces" include:

' ' (0x20) space (SPC)

'\t' (0x09) horizontal tab (TAB)

'\n' (0x0a) newline (LF)

'\v' (0x0b) vertical tab (VT)

'\f' (0x0c) feed (FF)

'\r' (0x0d) carriage return (CR)

although there is no function which will do all of the work for you, you will have to roll your own solution to compare each side of the given character array repeatedly until no spaces remain.

Edit:

Since you have access to C++, Boost has a trim implementation waiting for you to make your life a lot easier.

What to use instead of "addPreferencesFromResource" in a PreferenceActivity?

@Garret Wilson Thank you so much! As a noob to android coding, I've been stuck with the preferences incompatibility issue for so many hours, and I find it so disappointing they deprecated the use of some methods/approaches for new ones that aren't supported by the older APIs thus having to resort to all sorts of workarounds to make your app work in a wide range of devices. It's really frustrating!

Your class is great, for it allows you to keep working in new APIs wih preferences the way it used to be, but it's not backward compatible. Since I'm trying to reach a wide range of devices I tinkered with it a bit to make it work in pre API 11 devices as well as in newer APIs:

import android.annotation.TargetApi;
import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;

public class MyPrefsActivity extends PreferenceActivity
{
    private static int prefs=R.xml.myprefs;

    @Override
    protected void onCreate(final Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        try {
            getClass().getMethod("getFragmentManager");
            AddResourceApi11AndGreater();
        } catch (NoSuchMethodException e) { //Api < 11
            AddResourceApiLessThan11();
        }
    }

    @SuppressWarnings("deprecation")
    protected void AddResourceApiLessThan11()
    {
        addPreferencesFromResource(prefs);
    }

    @TargetApi(11)
    protected void AddResourceApi11AndGreater()
    {
        getFragmentManager().beginTransaction().replace(android.R.id.content,
                new PF()).commit();
    }

    @TargetApi(11)
    public static class PF extends PreferenceFragment
    {       
        @Override
        public void onCreate(final Bundle savedInstanceState)
        {
            super.onCreate(savedInstanceState);
            addPreferencesFromResource(MyPrefsActivity.prefs); //outer class
            // private members seem to be visible for inner class, and
            // making it static made things so much easier
        }
    }
}

Tested in two emulators (2.2 and 4.2) with success.

Why my code looks so crappy:

I'm a noob to android coding, and I'm not the greatest java fan.

In order to avoid the deprecated warning and to force Eclipse to allow me to compile I had to resort to annotations, but these seem to affect only classes or methods, so I had to move the code onto two new methods to take advantage of this.

I wouldn't like having to write my xml resource id twice anytime I copy&paste the class for a new PreferenceActivity, so I created a new variable to store this value.

I hope this will be useful to somebody else.

P.S.: Sorry for my opinionated views, but when you come new and find such handicaps, you can't help it but to get frustrated!

How to use XPath in Python?

If you are going to need it for html:

import lxml.html as html
root  = html.fromstring(string)
root.xpath('//meta')

Complex numbers usage in python

The following example for complex numbers should be self explanatory including the error message at the end

>>> x=complex(1,2)
>>> print x
(1+2j)
>>> y=complex(3,4)
>>> print y
(3+4j)
>>> z=x+y
>>> print x
(1+2j)
>>> print z
(4+6j)
>>> z=x*y
>>> print z
(-5+10j)
>>> z=x/y
>>> print z
(0.44+0.08j)
>>> print x.conjugate()
(1-2j)
>>> print x.imag
2.0
>>> print x.real
1.0
>>> print x>y

Traceback (most recent call last):
  File "<pyshell#149>", line 1, in <module>
    print x>y
TypeError: no ordering relation is defined for complex numbers
>>> print x==y
False
>>> 

Python try-else

try:
    statements # statements that can raise exceptions
except:
    statements # statements that will be executed to handle exceptions
else:
    statements # statements that will be executed if there is no exception

Example :

try:
    age=int(input('Enter your age: '))
except:
    print ('You have entered an invalid value.')
else:
    if age <= 21:
        print('You are not allowed to enter, you are too young.')
    else:
        print('Welcome, you are old enough.')

The Output :

>>> 
Enter your age: a
You have entered an invalid value.
>>> RESTART
>>> 
Enter your age: 25
Welcome, you are old enough.
>>>RESTART
>>> 
Enter your age: 13
You are not allowed to enter, you are too young.
>>>

Copied from : https://geek-university.com/python/the-try-except-else-statements/

How can I represent an 'Enum' in Python?

davidg recommends using dicts. I'd go one step further and use sets:

months = set('January', 'February', ..., 'December')

Now you can test whether a value matches one of the values in the set like this:

if m in months:

like dF, though, I usually just use string constants in place of enums.

Pdf.js: rendering a pdf file using a base64 file source instead of url

According to the examples base64 encoding is directly supported, although I've not tested it myself. Take your base64 string (derived from a file or loaded with any other method, POST/GET, websockets etc), turn it to a binary with atob, and then parse this to getDocument on the PDFJS API likePDFJS.getDocument({data: base64PdfData}); Codetoffel answer does work just fine for me though.

how to add value to a tuple?

I was going through some details related to tuple and list, and what I understood is:

  • Tuples are Heterogeneous collection data type
  • Tuple has Fixed length (per tuple type)
  • Tuple are Always finite

So for appending new item to a tuple, need to cast it to list, and do append() operation on it, then again cast it back to tuple.

But personally what I felt about the Question is, if Tuples are supposed to be finite, fixed length items and if we are using those data types in our application logics then there should not be a scenario to appending new items OR updating an item value in it. So instead of list of tuples it should be list of list itself, Am I right on this?

How do I catch a numpy warning like it's an exception (not just for testing)?

It seems that your configuration is using the print option for numpy.seterr:

>>> import numpy as np
>>> np.array([1])/0   #'warn' mode
__main__:1: RuntimeWarning: divide by zero encountered in divide
array([0])
>>> np.seterr(all='print')
{'over': 'warn', 'divide': 'warn', 'invalid': 'warn', 'under': 'ignore'}
>>> np.array([1])/0   #'print' mode
Warning: divide by zero encountered in divide
array([0])

This means that the warning you see is not a real warning, but it's just some characters printed to stdout(see the documentation for seterr). If you want to catch it you can:

  1. Use numpy.seterr(all='raise') which will directly raise the exception. This however changes the behaviour of all the operations, so it's a pretty big change in behaviour.
  2. Use numpy.seterr(all='warn'), which will transform the printed warning in a real warning and you'll be able to use the above solution to localize this change in behaviour.

Once you actually have a warning, you can use the warnings module to control how the warnings should be treated:

>>> import warnings
>>> 
>>> warnings.filterwarnings('error')
>>> 
>>> try:
...     warnings.warn(Warning())
... except Warning:
...     print 'Warning was raised as an exception!'
... 
Warning was raised as an exception!

Read carefully the documentation for filterwarnings since it allows you to filter only the warning you want and has other options. I'd also consider looking at catch_warnings which is a context manager which automatically resets the original filterwarnings function:

>>> import warnings
>>> with warnings.catch_warnings():
...     warnings.filterwarnings('error')
...     try:
...         warnings.warn(Warning())
...     except Warning: print 'Raised!'
... 
Raised!
>>> try:
...     warnings.warn(Warning())
... except Warning: print 'Not raised!'
... 
__main__:2: Warning: 

Reference alias (calculated in SELECT) in WHERE clause

You can't reference an alias except in ORDER BY because SELECT is the second last clause that's evaluated. Two workarounds:

SELECT BalanceDue FROM (
  SELECT (InvoiceTotal - PaymentTotal - CreditTotal) AS BalanceDue
  FROM Invoices
) AS x
WHERE BalanceDue > 0;

Or just repeat the expression:

SELECT (InvoiceTotal - PaymentTotal - CreditTotal) AS BalanceDue
FROM Invoices
WHERE  (InvoiceTotal - PaymentTotal - CreditTotal)  > 0;

I prefer the latter. If the expression is extremely complex (or costly to calculate) you should probably consider a computed column (and perhaps persisted) instead, especially if a lot of queries refer to this same expression.

PS your fears seem unfounded. In this simple example at least, SQL Server is smart enough to only perform the calculation once, even though you've referenced it twice. Go ahead and compare the plans; you'll see they're identical. If you have a more complex case where you see the expression evaluated multiple times, please post the more complex query and the plans.

Here are 5 example queries that all yield the exact same execution plan:

SELECT LEN(name) + column_id AS x
FROM sys.all_columns
WHERE LEN(name) + column_id > 30;

SELECT x FROM (
SELECT LEN(name) + column_id AS x
FROM sys.all_columns
) AS x
WHERE x > 30;

SELECT LEN(name) + column_id AS x
FROM sys.all_columns
WHERE column_id + LEN(name) > 30;

SELECT name, column_id, x FROM (
SELECT name, column_id, LEN(name) + column_id AS x
FROM sys.all_columns
) AS x
WHERE x > 30;

SELECT name, column_id, x FROM (
SELECT name, column_id, LEN(name) + column_id AS x
FROM sys.all_columns
) AS x
WHERE LEN(name) + column_id > 30;

Resulting plan for all five queries:

enter image description here

How to call multiple functions with @click in vue?

On Vue 2.3 and above you can do this:

<div v-on:click="firstFunction(); secondFunction();"></div>
// or
<div @click="firstFunction(); secondFunction();"></div>

How can I get Git to follow symlinks?

I used to add files beyond symlinks for quite some time now. This used to work just fine, without making any special arrangements. Since I updated to Git 1.6.1, this does not work any more.

You may be able to switch to Git 1.6.0 to make this work. I hope that a future version of Git will have a flag to git-add allowing it to follow symlinks again.

Ternary operation in CoffeeScript

CoffeeScript has no ternary operator. That's what the docs say.

You can still use a syntax like

a = true then 5 else 10

It's way much clearer.

PostgreSQL DISTINCT ON with different ORDER BY

Window function may solve that in one pass:

SELECT DISTINCT ON (address_id) 
   LAST_VALUE(purchases.address_id) OVER wnd AS address_id
FROM "purchases"
WHERE "purchases"."product_id" = 1
WINDOW wnd AS (
   PARTITION BY address_id ORDER BY purchases.purchased_at DESC
   ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)

Uncaught TypeError: undefined is not a function on loading jquery-min.js

This solution worked for me


    ;(function($){
        // your code
    })(jQuery);

Move your code inside the closure and use $ instead of jQuery

I found the above solution in https://magento.stackexchange.com/questions/33348/uncaught-typeerror-undefined-is-not-a-function-when-using-a-jquery-plugin-in-ma

after seraching too much

How can I create a memory leak in Java?

If you don't use a compacting garbage collector, you can have some sort of a memory leak due to heap fragmentation.

TypeError: 'type' object is not subscriptable when indexing in to a dictionary

Normally Python throws NameError if the variable is not defined:

>>> d[0]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'd' is not defined

However, you've managed to stumble upon a name that already exists in Python.

Because dict is the name of a built-in type in Python you are seeing what appears to be a strange error message, but in reality it is not.

The type of dict is a type. All types are objects in Python. Thus you are actually trying to index into the type object. This is why the error message says that the "'type' object is not subscriptable."

>>> type(dict)
<type 'type'>
>>> dict[0]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'type' object is not subscriptable

Note that you can blindly assign to the dict name, but you really don't want to do that. It's just going to cause you problems later.

>>> dict = {1:'a'}
>>> type(dict)
<class 'dict'>
>>> dict[1]
'a'

The true source of the problem is that you must assign variables prior to trying to use them. If you simply reorder the statements of your question, it will almost certainly work:

d = {1: "walk1.png", 2: "walk2.png", 3: "walk3.png"}
m1 = pygame.image.load(d[1])
m2 = pygame.image.load(d[2])
m3 = pygame.image.load(d[3])
playerxy = (375,130)
window.blit(m1, (playerxy))

QString to char* conversion

Qt provides the simplest API

const char *qPrintable(const QString &str)
const char *qUtf8Printable(const QString &str)

If you want non-const data pointer use

str.toLocal8Bit().data()
str.toUtf8().data()

Turn ON/OFF Camera LED/flash light in Samsung Galaxy Ace 2.2.1 & Galaxy Tab

I will soon released a new version of my app to support to galaxy ace.

You can download here: https://play.google.com/store/apps/details?id=droid.pr.coolflashlightfree

In order to solve your problem you should do this:

this._camera = Camera.open();     
this._camera.startPreview();
this._camera.autoFocus(new AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
}
});

Parameters params = this._camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_ON);
this._camera.setParameters(params);

params = this._camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_OFF);
this._camera.setParameters(params);

don't worry about FLASH_MODE_OFF because this will keep the light on, strange but it's true

to turn off the led just release the camera

How to set the environmental variable LD_LIBRARY_PATH in linux

Add

LD_LIBRARY_PATH="/path/you/want1:/path/you/want/2"

to /etc/environment

See the Ubuntu Documentation.

CORRECTION: I should take my own advice and actually read the documentation. It says that this does not apply to LD_LIBRARY_PATH: Since Ubuntu 9.04 Jaunty Jackalope, LD_LIBRARY_PATH cannot be set in $HOME/.profile, /etc/profile, nor /etc/environment files. You must use /etc/ld.so.conf.d/.conf configuration files.* So user1824407's answer is spot on.

Adding a directory to PATH in Ubuntu

The file .bashrc is read when you start an interactive shell. This is the file that you should update. E.g:

export PATH=$PATH:/opt/ActiveTcl-8.5/bin

Restart the shell for the changes to take effect or source it, i.e.:

source .bashrc

Force update of an Android app when a new version is available

Officially google provide an Android API for this.

The API is currently being tested with a handful of partners, and will become available to all developers soon.

Update API is available now - https://developer.android.com/guide/app-bundle/in-app-updates

Why do symbols like apostrophes and hyphens get replaced with black diamonds on my website?

It's an encoding problem. You have to set the correct encoding in the HTML head via meta tag:

<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

Replace "ISO-8859-1" with whatever your encoding is (e.g. 'UTF-8'). You must find out what encoding your HTML files are. If you're on an Unix system, just type file file.html and it should show you the encoding. If this is not possible, you should be able to find out somewhere what encoding your editor produces.

pass JSON to HTTP POST Request

You don't want multipart, but a "plain" POST request (with Content-Type: application/json) instead. Here is all you need:

var request = require('request');

var requestData = {
  request: {
    slice: [
      {
        origin: "ZRH",
        destination: "DUS",
        date: "2014-12-02"
      }
    ],
    passengers: {
      adultCount: 1,
      infantInLapCount: 0,
      infantInSeatCount: 0,
      childCount: 0,
      seniorCount: 0
    },
    solutions: 2,
    refundable: false
  }
};

request('https://www.googleapis.com/qpxExpress/v1/trips/search?key=myApiKey',
        { json: true, body: requestData },
        function(err, res, body) {
  // `body` is a js object if request was successful
});

Android Respond To URL in Intent

You might need to allow different combinations of data in your intent filter to get it to work in different cases (http/ vs https/, www. vs no www., etc).

For example, I had to do the following for an app which would open when the user opened a link to Google Drive forms (www.docs.google.com/forms)

Note that path prefix is optional.

        <intent-filter>
            <action android:name="android.intent.action.VIEW" />
            <category android:name="android.intent.category.DEFAULT" />
            <category android:name="android.intent.category.BROWSABLE" />

            <data android:scheme="http" />
            <data android:scheme="https" />

            <data android:host="www.docs.google.com" />
            <data android:host="docs.google.com" />

            <data android:pathPrefix="/forms" />
        </intent-filter>

How to add to the PYTHONPATH in Windows, so it finds my modules/packages?

From Windows command line:

set PYTHONPATH=%PYTHONPATH%;C:\My_python_lib

To set the PYTHONPATH permanently, add the line to your autoexec.bat. Alternatively, if you edit the system variable through the System Properties, it will also be changed permanently.

Trouble using ROW_NUMBER() OVER (PARTITION BY ...)

I would do something like this:

;WITH x 
 AS (SELECT *, 
            Row_number() 
              OVER( 
                partition BY employeeid 
                ORDER BY datestart) rn 
     FROM   employeehistory) 
SELECT * 
FROM   x x1 
   LEFT OUTER JOIN x x2 
                ON x1.rn = x2.rn + 1 

Or maybe it would be x2.rn - 1. You'll have to see. In any case, you get the idea. Once you have the table joined on itself, you can filter, group, sort, etc. to get what you need.

Plot two histograms on single chart with matplotlib

As a completion to Gustavo Bezerra's answer:

If you want each histogram to be normalized (normed for mpl<=2.1 and density for mpl>=3.1) you cannot just use normed/density=True, you need to set the weights for each value instead:

import numpy as np
import matplotlib.pyplot as plt

x = np.random.normal(1, 2, 5000)
y = np.random.normal(-1, 3, 2000)
x_w = np.empty(x.shape)
x_w.fill(1/x.shape[0])
y_w = np.empty(y.shape)
y_w.fill(1/y.shape[0])
bins = np.linspace(-10, 10, 30)

plt.hist([x, y], bins, weights=[x_w, y_w], label=['x', 'y'])
plt.legend(loc='upper right')
plt.show()

enter image description here

As a comparison, the exact same x and y vectors with default weights and density=True:

enter image description here

Difference between natural join and inner join

SQL is not faithful to the relational model in many ways. The result of a SQL query is not a relation because it may have columns with duplicate names, 'anonymous' (unnamed) columns, duplicate rows, nulls, etc. SQL doesn't treat tables as relations because it relies on column ordering etc.

The idea behind NATURAL JOIN in SQL is to make it easier to be more faithful to the relational model. The result of the NATURAL JOIN of two tables will have columns de-duplicated by name, hence no anonymous columns. Similarly, UNION CORRESPONDING and EXCEPT CORRESPONDING are provided to address SQL's dependence on column ordering in the legacy UNION syntax.

However, as with all programming techniques it requires discipline to be useful. One requirement for a successful NATURAL JOIN is consistently named columns, because joins are implied on columns with the same names (it is a shame that the syntax for renaming columns in SQL is verbose but the side effect is to encourage discipline when naming columns in base tables and VIEWs :)

Note a SQL NATURAL JOIN is an equi-join**, however this is no bar to usefulness. Consider that if NATURAL JOIN was the only join type supported in SQL it would still be relationally complete.

While it is indeed true that any NATURAL JOIN may be written using INNER JOIN and projection (SELECT), it is also true that any INNER JOIN may be written using product (CROSS JOIN) and restriction (WHERE); further note that a NATURAL JOIN between tables with no column names in common will give the same result as CROSS JOIN. So if you are only interested in results that are relations (and why ever not?!) then NATURAL JOIN is the only join type you need. Sure, it is true that from a language design perspective shorthands such as INNER JOIN and CROSS JOIN have their value, but also consider that almost any SQL query can be written in 10 syntactically different, but semantically equivalent, ways and this is what makes SQL optimizers so very hard to develop.

Here are some example queries (using the usual parts and suppliers database) that are semantically equivalent:

SELECT *
  FROM S NATURAL JOIN SP;

-- Must disambiguate and 'project away' duplicate SNO attribute
SELECT S.SNO, SNAME, STATUS, CITY, PNO, QTY
  FROM S INNER JOIN SP 
          USING (SNO);                        

-- Alternative projection
SELECT S.*, PNO, QTY
  FROM S INNER JOIN SP 
          ON S.SNO = SP.SNO;

-- Same columns, different order == equivalent?!
SELECT SP.*, S.SNAME, S.STATUS, S.CITY
  FROM S INNER JOIN SP 
      ON S.SNO = SP.SNO;

-- 'Old school'
SELECT S.*, PNO, QTY
  FROM S, SP 
 WHERE S.SNO = SP.SNO;

** Relational natural join is not an equijoin, it is a projection of one. – philipxy

Is there a way to use PhantomJS in Python?

The answer by @Pykler is great but the Node requirement is outdated. The comments in that answer suggest the simpler answer, which I've put here to save others time:

  1. Install PhantomJS

    As @Vivin-Paliath points out, it's a standalone project, not part of Node.

    Mac:

    brew install phantomjs
    

    Ubuntu:

    sudo apt-get install phantomjs
    

    etc

  2. Set up a virtualenv (if you haven't already):

    virtualenv mypy  # doesn't have to be "mypy". Can be anything.
    . mypy/bin/activate
    

    If your machine has both Python 2 and 3 you may need run virtualenv-3.6 mypy or similar.

  3. Install selenium:

    pip install selenium
    
  4. Try a simple test, like this borrowed from the docs:

    from selenium import webdriver
    from selenium.webdriver.common.keys import Keys
    
    driver = webdriver.PhantomJS()
    driver.get("http://www.python.org")
    assert "Python" in driver.title
    elem = driver.find_element_by_name("q")
    elem.clear()
    elem.send_keys("pycon")
    elem.send_keys(Keys.RETURN)
    assert "No results found." not in driver.page_source
    driver.close()
    

Can't bind to 'ngIf' since it isn't a known property of 'div'

Just for anyone who still has an issue, I also had an issue where I typed ngif rather than ngIf (notice the capital 'I').

Create PDF from a list of images

How about this??

from fpdf import FPDF
from PIL import Image
import glob
import os


# set here
image_directory = '/path/to/imageDir'
extensions = ('*.jpg','*.png','*.gif') #add your image extentions
# set 0 if you want to fit pdf to image
# unit : pt
margin = 10

imagelist=[]
for ext in extensions:
    imagelist.extend(glob.glob(os.path.join(image_directory,ext)))

for imagePath in imagelist:
    cover = Image.open(imagePath)
    width, height = cover.size

pdf = FPDF(unit="pt", format=[width + 2*margin, height + 2*margin])
pdf.add_page()

pdf.image(imagePath, margin, margin)

destination = os.path.splitext(imagePath)[0]
pdf.output(destination + ".pdf", "F")

How to check if a String contains another String in a case insensitive manner in Java?

A simpler way of doing this (without worrying about pattern matching) would be converting both Strings to lowercase:

String foobar = "fooBar";
String bar = "FOO";
if (foobar.toLowerCase().contains(bar.toLowerCase()) {
    System.out.println("It's a match!");
}

Maximum concurrent connections to MySQL

As per the MySQL docs: http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html#sysvar_max_user_connections

 maximum range: 4,294,967,295  (e.g. 2**32 - 1)

You'd probably run out of memory, file handles, and network sockets, on your server long before you got anywhere close to that limit.

List of zeros in python

$ python3
>>> from itertools import repeat
>>> list(repeat(0, 7))
[0, 0, 0, 0, 0, 0, 0]

filtering NSArray into a new NSArray in Objective-C

If you are OS X 10.6/iOS 4.0 or later, you're probably better off with blocks than NSPredicate. See -[NSArray indexesOfObjectsPassingTest:] or write your own category to add a handy -select: or -filter: method (example).

Want somebody else to write that category, test it, etc.? Check out BlocksKit (array docs). And there are many more examples to be found by, say, searching for e.g. "nsarray block category select".

Why is the Android emulator so slow? How can we speed up the Android emulator?

I tried booting the emulator from Eclipse (Indigo and Android 1.5, no Snapshot) and after 45 minutes I stopped it, because nothing had happened.

Statistics: Phenom Quad @2.6 MHz with 4 GB DDR2 Corsair Dominator @800 MHz. The AVD is on an SSD drive and the emulator on a 7200 RPM HDD.

I started the emulator manually with the -no-boot-anim option and it loaded in 30 seconds. :)

In CMD, navigate to folder where the emulator.exe file is and type

emulator.exe @<YourAVDFromEclipse> -no-boot-anim

The emulator.exe file is located in the Android SDK folder under Tools.

In Windows, you can find the the Android Virtual Device(AVD) under C:\Users\<NAME>\.android\avd.

The projects run from inside Eclipse, targeting the AVD you booted, show up just nicely :D

How big can a MySQL database get before performance starts to degrade

I once was called upon to look at a mysql that had "stopped working". I discovered that the DB files were residing on a Network Appliance filer mounted with NFS2 and with a maximum file size of 2GB. And sure enough, the table that had stopped accepting transactions was exactly 2GB on disk. But with regards to the performance curve I'm told that it was working like a champ right up until it didn't work at all! This experience always serves for me as a nice reminder that there're always dimensions above and below the one you naturally suspect.

Get commit list between tags in git

Consider also this:

git range-diff tagA...tagB

Source: https://git-scm.com/docs/git-range-diff

How can I clear the content of a file?

Use FileMode.Truncate everytime you create the file. Also place the File.Create inside a try catch.

Angular.js and HTML5 date input value -- how to get Firefox to show a readable date value in a date input?

You can use this, it works fine:

<input type="date" class="form1"  
  value="{{date | date:MM/dd/yyyy}}"
  ng-model="date" 
  name="id" 
  validatedateformat 
  data-date-format="mm/dd/yyyy"
  maxlength="10" 
  id="id" 
  calendar 
  maxdate="todays"
  ng-click="openCalendar('id')">
    <span class="input-group-addon">
      <span class="glyphicon glyphicon-calendar" ng-click="openCalendar('id')"></span>
    </span>
</input>

Why won't bundler install JSON gem?

For OS X make sure you have coreutils

$ brew install coreutils
$ bundle

How to write a simple Java program that finds the greatest common divisor between two numbers?

import java.util.Scanner;

class CalculateGCD 
{   
  public static int calGCD(int a, int b) 
  { 
   int c=0,d=0;  
   if(a>b){c=b;} 
   else{c=a;}  
   for(int i=c; i>0; i--) 
   { 
    if(((a%i)+(b%i))==0) 
    { 
     d=i; 
     break; 
    } 
   } 
   return d;  
  }  

  public static void main(String args[]) 
  { 
   Scanner sc=new Scanner(System.in); 
   System.out.println("Enter the nos whose GCD is to be calculated:"); 
   int a=sc.nextInt(); 
   int b=sc.nextInt(); 
   System.out.println(calGCD(a,b));  
  } 
 } 

Get time difference between two dates in seconds

Below code will give the time difference in second.

var date1 = new Date(); // current date
var date2 = new Date("06/26/2018"); // mm/dd/yyyy format
var timeDiff = Math.abs(date2.getTime() - date1.getTime()); // in miliseconds
var timeDiffInSecond = Math.ceil(timeDiff / 1000); // in second

alert(timeDiffInSecond );

How to print variables in Perl

How do I print out my $ids and $nIds?
print "$ids\n";
print "$nIds\n";
I tried simply print $ids, but Perl complains.

Complains about what? Uninitialised value? Perhaps your loop was never entered due to an error opening the file. Be sure to check if open returned an error, and make sure you are using use strict; use warnings;.

my ($ids, $nIds) is a list, right? With two elements?

It's a (very special) function call. $ids,$nIds is a list with two elements.

How to call on a function found on another file?

Your sprite is created mid way through the playerSprite function... it also goes out of scope and ceases to exist at the end of that same function. The sprite must be created where you can pass it to playerSprite to initialize it and also where you can pass it to your draw function.

Perhaps declare it above your first while?

Using JAXB to unmarshal/marshal a List<String>

Finally I've solved it using JacksonJaxbJsonProvider It requires few changes in your Spring context.xml and Maven pom.xml

In your Spring context.xml add JacksonJaxbJsonProvider to the <jaxrs:server>:

<jaxrs:server id="restService" address="/resource">
    <jaxrs:providers>
        <bean class="org.codehaus.jackson.jaxrs.JacksonJaxbJsonProvider"/>
    </jaxrs:providers>
</jaxrs:server>

In your Maven pom.xml add:

<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-jaxrs</artifactId>
    <version>1.9.0</version>
</dependency>

SecurityError: The operation is insecure - window.history.pushState()

We experienced the SecurityError: The operation is insecure when a user disabled their cookies prior to visiting our site, any subsequent XHR requests trying to use the session would obviously fail and cause this error.

Changing image size in Markdown

This one works for me it's not in one line but i hope it works for you.

<div>
<img src="attachment:image.png" width="500" height="300"/>
</div>

SQL Case Expression Syntax?

Here are the CASE statement examples from the PostgreSQL docs (Postgres follows the SQL standard here):

SELECT a,
   CASE WHEN a=1 THEN 'one'
        WHEN a=2 THEN 'two'
        ELSE 'other'
   END
FROM test;

or

SELECT a,
   CASE a WHEN 1 THEN 'one'
          WHEN 2 THEN 'two'
          ELSE 'other'
   END
FROM test;

Obviously the second form is cleaner when you are just checking one field against a list of possible values. The first form allows more complicated expressions.

How do I simulate a low bandwidth, high latency environment?

You can try this: CovenantSQL/GNTE just write YAML like this:

group:
  - 
    name: china
    nodes:
      - 
        ip: 10.250.1.2
        cmd: "cd /scripts && ./YourBin args"
      - 
        ip: 10.250.1.3
        cmd: "cd /scripts && ./YourBin args"
    delay: "100ms 10ms 30%"
    loss: "1% 10%"
  - 
    name: us
    nodes:
      - 
        ip: 10.250.2.2
        cmd: "cd /scripts && ./YourBin args"
      - 
        ip: 10.250.2.3
        cmd: "cd /scripts && ./YourBin args"
    delay: "1000ms 10ms 30%"
    loss: "1% 10%"

network:
  -
    groups:
      - china
      - us
    delay: "200ms 10ms 1%"
    corrupt: "0.2%"
    rate: "10mbit"

run ./generate scripts/your.yaml

Get Image Height and Width as integer values?

Try like this:

list($width, $height) = getimagesize('path_to_image');

Make sure that:

  1. You specify the correct image path there
  2. The image has read access
  3. Chmod image dir to 755

Also try to prefix path with $_SERVER["DOCUMENT_ROOT"], this helps sometimes when you are not able to read files.

Print DIV content by JQuery

your question doesn't sound as if you even tried it yourself, so i shouldn't even think of answering, but: if a hidden div can't be printed with that one line:

$('SelectorToPrint').printElement();

simply change it to:

$('SelectorToPrint').show().printElement();

which should make it work in all cases.

for the rest, there's no solution. the plugin will open the print-dialog for you where the user has to choose his printer. you simply can't find out if a printer is attached with javascript (and you (almost) can't print without print-dialog - if you're thinking about that).

NOTE:

The $.browser object has been removed in version 1.9.x of jQuery making this library unsupported.

Do we need type="text/css" for <link> in HTML5

For LINK elements the content-type is determined in the HTTP-response so the type attribute is superfluous. This is OK for all browsers.

Custom Authentication in ASP.Net-Core

I would like to add something to brilliant @AmiNadimi answer for everyone who going implement his solution in .NET Core 3:

First of all, you should change signature of SignIn method in UserManager class from:

public async void SignIn(HttpContext httpContext, UserDbModel user, bool isPersistent = false)

to:

public async Task SignIn(HttpContext httpContext, UserDbModel user, bool isPersistent = false)

It's because you should never use async void, especially if you work with HttpContext. Source: Microsoft Docs

The last, but not least, your Configure() method in Startup.cs should contains app.UseAuthorization and app.UseAuthentication in proper order:

if (env.IsDevelopment())
{
    app.UseDeveloperExceptionPage();
}
else
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseAuthentication();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
    endpoints.MapControllerRoute(
        name: "default",
        pattern: "{controller=Home}/{action=Index}/{id?}");
});

How do you set the document title in React?

If you're a beginner you can just save yourself from all that by going to the public folder of your react project folder and edit the title in "index.html" and put yours. Don't forget to save so it will reflect.

How to set JFrame to appear centered, regardless of monitor resolution?

Use setLocationRelativeTo(null)

This method has a special effect when you pass it a null. According to the Javadoc:

If the component is null, or the GraphicsConfiguration associated with this component is null, the window is placed in the center of the screen.

This should be done after setting the size or calling pack(), but before setting it visible, like this:

frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);

Proper usage of .net MVC Html.CheckBoxFor

I had trouble getting this to work and added another solution for anyone wanting/ needing to use FromCollection.

Instead of:

@Html.CheckBoxFor(model => true, item.TemplateId) 

Format html helper like so:

@Html.CheckBoxFor(model => model.SomeProperty, new { @class = "form-control", Name = "SomeProperty"})

Then in the viewmodel/model wherever your logic is:

public void Save(FormCollection frm)
{   
    // to do instantiate object.

    instantiatedItem.SomeProperty = (frm["SomeProperty"] ?? "").Equals("true", StringComparison.CurrentCultureIgnoreCase);

    // to do and save changes in database.
}

How to convert number to words in java

This program can convert up to 102 digits long number. Suggestions and comments are highly appreciated.

package com.kegeesoft;
/**
 * @author Chandana Gamage +94 710 980 120
 * @author [email protected]
 * @author KeGee Software Solutions
 */
import java.math.BigDecimal;
import java.math.BigInteger;

public class Converter {
    private final BigInteger zero = new BigInteger("0");        
    private final BigInteger scale[] = new BigInteger[33];                                        
    private final String scaleName[] = {" Duotrigintillion"," Untrigintillion"," Trigintillion",
                                        " Nonvigintillion"," Octovigintillion"," Septvigintillion",
                                        " Sexvigintillion"," Quinvigintillion"," Quattuorvigintillion",
                                        " Trevigintillion"," Duovigintillion"," Unvigintillion",
                                        " Vigintillion"," Novemdecillion"," Octodecillion",
                                        " Septemdecillion"," Sexdecillion"," Quindecillion",
                                        " Quattuordecillion "," Tredecillion"," Duodecillion",
                                        " Undecillion"," Decillion"," Nonillion"," Octillion",
                                        " Septillion"," Sextillion"," Quintillion"," Quadrillion",
                                        " Trillion"," Billion"," Million"," Thousand"};
    private final String ones[] = {""," One"," Two"," Three"," Four"," Five"," Six"," Seven"," Eight"," Nine",
                                   " Ten"," Eleven"," Twelve"," Thirteen"," Fourteen"," Fifteen"," Sixteen",
                                   " Seventeen"," Eighteen"," Nineteen"};    
    private final String tens[] = {"",""," Twenty"," Thirty"," Forty"," Fifty"," Sixty"," Seventy"," Eighty"," Ninety"};
    private int index = 0;    
    private String shortValueInWords = "";
    private String output = "";
    private String decimalInWords = "";
    private String valueInWords;

    public String setValue(BigInteger value) throws Exception{
        return this.bigValueInWords(value);
    }

    public String setValue(BigDecimal value) throws Exception{
        int indexOfDecimalPoint = (value.toString()).indexOf(".");

        // Split and pass interger value of given decimal value to constructor
        String tempIntValue = (value.toString()).substring(0, indexOfDecimalPoint);
        BigInteger intValue = new BigInteger(tempIntValue);

        // Split and pass decimal value of given decimal value to constructor
        String tempDeciValue = (value.toString()).substring(indexOfDecimalPoint+1, value.toString().length());
        BigInteger deciValue = new BigInteger(tempDeciValue);

        this.bigValueInWords(intValue);
        this.decimalValueInWords(deciValue);
        return null;
    }

    public String setValue(BigDecimal value, String currencyName, String centsName) throws Exception{
        int indexOfDecimalPoint = (value.toString()).indexOf(".");

        // Split and pass interger value of given decimal value to constructor
        String tempIntValue = (value.toString()).substring(0, indexOfDecimalPoint);
        BigInteger intValue = new BigInteger(tempIntValue);

        // Split and pass decimal value of given decimal value to constructor
        String tempDeciValue = (value.toString()).substring(indexOfDecimalPoint+1, value.toString().length());
        @SuppressWarnings("UnusedAssignment")
        BigInteger deciValue = null;

        // Concatenate "0" if decimal value has only single digit
        if(tempDeciValue.length() == 1){
            deciValue = new BigInteger(tempDeciValue.concat("0"));
        }else{
            deciValue = new BigInteger(tempDeciValue);
        }

        this.output = currencyName+" ";
        this.bigValueInWords(intValue);
        this.centsValueInWords(deciValue, centsName);

        return null;
    }

    private String bigValueInWords(BigInteger value) throws Exception{
        // Build scale array
        int exponent = 99;
        for (int i = 0; i < scale.length; i++) {
            scale[i] = new BigInteger("10").pow(exponent);
            exponent = exponent - 3;
        }

        /* Idntify whether given value is a minus value or not
            if == yes then pass value without minus sign
            and pass Minus word to output
        */
        if(value.compareTo(zero) == -1){
            value = new BigInteger(value.toString().substring(1,value.toString().length()));
            output += "Minus ";
        }

        // Get value in words of big numbers (duotrigintillions to thousands)
        for (int i=0; i < scale.length; i++) {
            if((value.divide(scale[i])).compareTo(zero)==1){
            this.index = (int)(value.divide(scale[i])).intValue();
            output += shortValueInWords(this.index) + scaleName[i];
            value = value.mod(scale[i]);
            }
        }

        // Get value in words of short numbers (hundreds, tens and ones)
        output += shortValueInWords((int)(value.intValue()));

        // Get rid of any space at the beginning of output and return value in words
        return this.valueInWords = output.replaceFirst("\\s", "");
    }

    private String shortValueInWords(int shortValue) throws Exception{
        // Get hundreds
        if(String.valueOf(shortValue).length()==3){
            shortValueInWords = ones[shortValue / 100]+" Hundred"+shortValueInWords(shortValue % 100);
        }

        // Get tens
        if(String.valueOf(shortValue).length()== 2 && shortValue >= 20){
            if((shortValue / 10)>=2 && (shortValue % 10)>=0){
                shortValueInWords = tens[shortValue / 10] + ones[shortValue % 10];
            }
        }

        // Get tens between 10 and 20
        if(String.valueOf(shortValue).length()== 2 && shortValue >= 10 && shortValue < 20){
            shortValueInWords = ones[shortValue];
        }

        // Get ones
        if(String.valueOf(shortValue).length()==1){
            shortValueInWords = ones[shortValue];
        }

        return this.shortValueInWords;
    }

    private String decimalValueInWords(BigInteger decimalValue) throws Exception{
        decimalInWords = " Point";
        // Get decimals in point form (0.563 = zero point five six three)
        for(int i=0; i < (decimalValue.toString().length()); i++){
            decimalInWords += ones[Integer.parseInt(String.valueOf(decimalValue.toString().charAt(i)))];
        }

        return this.decimalInWords;
    }

    private String centsValueInWords(BigInteger decimalValue, String centsName) throws Exception{
        decimalInWords = " and"+" "+centsName;

        // Get cents in words (5.52 = five and cents fifty two)
        if(decimalValue.intValue() == 0){
            decimalInWords += shortValueInWords(decimalValue.intValue())+" Zero only";
        }else{
            decimalInWords += shortValueInWords(decimalValue.intValue())+" only";
        }


        return this.decimalInWords;
    }

    public String getValueInWords(){
        return this.valueInWords + decimalInWords;
    }

    public static void main(String args[]){
        Converter c1 = new Converter();
        Converter c2 = new Converter();
        Converter c3 = new Converter();
        Converter c4 = new Converter();

        try{
            // Get integer value in words
            c1.setValue(new BigInteger("15634886"));
            System.out.println(c1.getValueInWords());

            // Get minus integer value in words
            c2.setValue(new BigInteger("-15634886"));
            System.out.println(c2.getValueInWords());

            // Get decimal value in words
            c3.setValue(new BigDecimal("358621.56895"));
            System.out.println(c3.getValueInWords());

            // Get currency value in words
            c4.setValue(new BigDecimal("358621.56"),"Dollar","Cents");
            System.out.println(c4.getValueInWords());
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}

How to remove list elements in a for loop in Python?

Probably a bit late to answer this but I just found this thread and I had created my own code for it previously...

    list = [1,2,3,4,5]
    deleteList = []
    processNo = 0
    for item in list:
        if condition:
            print item
            deleteList.insert(0, processNo)
        processNo += 1

    if len(deleteList) > 0:
        for item in deleteList:
            del list[item]

It may be a long way of doing it but seems to work well. I create a second list that only holds numbers that relate to the list item to delete. Note the "insert" inserts the list item number at position 0 and pushes the remainder along so when deleting the items, the list is deleted from the highest number back to the lowest number so the list stays in sequence.

Accessing attributes from an AngularJS directive

See section Attributes from documentation on directives.

observing interpolated attributes: Use $observe to observe the value changes of attributes that contain interpolation (e.g. src="{{bar}}"). Not only is this very efficient but it's also the only way to easily get the actual value because during the linking phase the interpolation hasn't been evaluated yet and so the value is at this time set to undefined.

printf \t option

A tab is a tab. How many spaces it consumes is a display issue, and depends on the settings of your shell.

If you want to control the width of your data, then you could use the width sub-specifiers in the printf format string. Eg. :

printf("%5d", 2);

It's not a complete solution (if the value is longer than 5 characters, it will not be truncated), but might be ok for your needs.

If you want complete control, you'll probably have to implement it yourself.

How to execute AngularJS controller function on page load?

Try this?

$scope.$on('$viewContentLoaded', function() {
    //call it here
});

AngularJS format JSON string output

You can use an optional parameter of JSON.stringify()

JSON.stringify(value[, replacer [, space]])

Parameters

  • value The value to convert to a JSON string.
  • replacer If a function, transforms values and properties encountered while stringifying; if an array, specifies the set of properties included in objects in the final string. A detailed description of the replacer function is provided in the javaScript guide article Using native JSON.
  • space Causes the resulting string to be pretty-printed.

For example:

JSON.stringify({a:1,b:2,c:{d:3, e:4}},null,"    ")

will give you following result:

"{
    "a": 1,
    "b": 2,
    "c": {
        "d": 3,
        "e": 4
    }
}"

How to create a fixed sidebar layout with Bootstrap 4?

I used this in my code:

<div class="sticky-top h-100">
    <nav id="sidebar" class="vh-100">
        ....

this cause your sidebar height become 100% and fixed at top.

How to check if a file exists in a folder?

Since nobody said how to check if the file exists AND get the current folder the executable is in (Working Directory):

if (File.Exists(Directory.GetCurrentDirectory() + @"\YourFile.txt")) {
                //do stuff
}

The @"\YourFile.txt" is not case sensitive, that means stuff like @"\YoUrFiLe.txt" and @"\YourFile.TXT" or @"\yOuRfILE.tXt" is interpreted the same.

In oracle, how do I change my session to display UTF8?

The character set is part of the locale, which is determined by the value of NLS_LANG. As the documentation makes clear this is an operating system variable:

NLS_LANG is set as an environment variable on UNIX platforms. NLS_LANG is set in the registry on Windows platforms.

Now we can use ALTER SESSION to change the values for a couple of locale elements, NLS_LANGUAGE and NLS_TERRITORY. But not, alas, the character set. The reason for this discrepancy is - I think - that the language and territory simply effect how Oracle interprets the stored data, e.g. whether to display a comma or a period when displaying a large number. Wheareas the character set is concerned with how the client application renders the displayed data. This information is picked up by the client application at startup time, and cannot be changed from within.

What is the difference between require() and library()?

Always use library. Never use require.

In a nutshell, this is because, when using require, your code might yield different, erroneous results, without signalling an error. This is rare but not hypothetical! Consider this code, which yields different results depending on whether {dplyr} can be loaded:

require(dplyr)

x = data.frame(y = seq(100))
y = 1
filter(x, y == 1)

This can lead to subtly wrong results. Using library instead of require throws an error here, signalling clearly that something is wrong. This is good.

It also makes debugging all other failures more difficult: If you require a package at the start of your script and use its exports in line 500, you’ll get an error message “object ‘foo’ not found” in line 500, rather than an error “there is no package called ‘bla’”.

The only acceptable use case of require is when its return value is immediately checked, as some of the other answers show. This is a fairly common pattern but even in these cases it is better (and recommended, see below) to instead separate the existence check and the loading of the package. That is: use requireNamespace instead of require in these cases.

More technically, require actually calls library internally (if the package wasn’t already attached — require thus performs a redundant check, because library also checks whether the package was already loaded). Here’s a simplified implementation of require to illustrate what it does:

require = function (package) {
    already_attached = paste('package:', package) %in% search()
    if (already_attached) return(TRUE)
    maybe_error = try(library(package, character.only = TRUE)) 
    success = ! inherits(maybe_error, 'try-error')
    if (! success) cat("Failed")
    success
}

Experienced R developers agree:

Yihui Xie, author of {knitr}, {bookdown} and many other packages says:

Ladies and gentlemen, I've said this before: require() is the wrong way to load an R package; use library() instead

Hadley Wickham, author of more popular R packages than anybody else, says

Use library(x) in data analysis scripts. […] You never need to use require() (requireNamespace() is almost always better)

Using Mockito with multiple calls to the same method with the same arguments

Related to @[Igor Nikolaev]'s answer from 8 years ago, using an Answer can be simplified somewhat using a lambda expression available in Java 8.

when(someMock.someMethod()).thenAnswer(invocation -> {
    doStuff();
    return;
});

or more simply:

when(someMock.someMethod()).thenAnswer(invocation -> doStuff());

What is the difference between And and AndAlso in VB.NET?

Interestingly none of the answers mentioned that And and Or in VB.NET are bit operators whereas OrElse and AndAlso are strictly Boolean operators.

Dim a = 3 OR 5 ' Will set a to the value 7, 011 or 101 = 111
Dim a = 3 And 5 ' Will set a to the value 1, 011 and 101 = 001
Dim b = 3 OrElse 5 ' Will set b to the value true and not evaluate the 5
Dim b = 3 AndAlso 5 ' Will set b to the value true after evaluating the 5
Dim c = 0 AndAlso 5 ' Will set c to the value false and not evaluate the 5

Note: a non zero integer is considered true; Dim e = not 0 will set e to -1 demonstrating Not is also a bit operator.

|| and && (the C# versions of OrElse and AndAlso) return the last evaluated expression which would be 3 and 5 respectively. This lets you use the idiom v || 5 in C# to give 5 as the value of the expression when v is null or (0 and an integer) and the value of v otherwise. The difference in semantics can catch a C# programmer dabbling in VB.NET off guard as this "default value idiom" doesn't work in VB.NET.

So, to answer the question: Use Or and And for bit operations (integer or Boolean). Use OrElse and AndAlso to "short circuit" an operation to save time, or test the validity of an evaluation prior to evaluating it. If valid(evaluation) andalso evaluation then or if not (unsafe(evaluation) orelse (not evaluation)) then

Bonus: What is the value of the following?

Dim e = Not 0 And 3

UILabel Align Text to center

In Swift 4.2 and Xcode 10

let lbl = UILabel(frame: CGRect(x: 10, y: 50, width: 230, height: 21))
lbl.textAlignment = .center //For center alignment
lbl.text = "This is my label fdsjhfg sjdg dfgdfgdfjgdjfhg jdfjgdfgdf end..."
lbl.textColor = .white
lbl.backgroundColor = .lightGray//If required
lbl.font = UIFont.systemFont(ofSize: 17)

 //To display multiple lines in label
lbl.numberOfLines = 0
lbl.lineBreakMode = .byWordWrapping

lbl.sizeToFit()//If required
yourView.addSubview(lbl)

How does numpy.newaxis work and when to use it?

Simply put, numpy.newaxis is used to increase the dimension of the existing array by one more dimension, when used once. Thus,

  • 1D array will become 2D array

  • 2D array will become 3D array

  • 3D array will become 4D array

  • 4D array will become 5D array

and so on..

Here is a visual illustration which depicts promotion of 1D array to 2D arrays.

newaxis canva visualization


Scenario-1: np.newaxis might come in handy when you want to explicitly convert a 1D array to either a row vector or a column vector, as depicted in the above picture.

Example:

# 1D array
In [7]: arr = np.arange(4)
In [8]: arr.shape
Out[8]: (4,)

# make it as row vector by inserting an axis along first dimension
In [9]: row_vec = arr[np.newaxis, :]     # arr[None, :]
In [10]: row_vec.shape
Out[10]: (1, 4)

# make it as column vector by inserting an axis along second dimension
In [11]: col_vec = arr[:, np.newaxis]     # arr[:, None]
In [12]: col_vec.shape
Out[12]: (4, 1)

Scenario-2: When we want to make use of numpy broadcasting as part of some operation, for instance while doing addition of some arrays.

Example:

Let's say you want to add the following two arrays:

 x1 = np.array([1, 2, 3, 4, 5])
 x2 = np.array([5, 4, 3])

If you try to add these just like that, NumPy will raise the following ValueError :

ValueError: operands could not be broadcast together with shapes (5,) (3,)

In this situation, you can use np.newaxis to increase the dimension of one of the arrays so that NumPy can broadcast.

In [2]: x1_new = x1[:, np.newaxis]    # x1[:, None]
# now, the shape of x1_new is (5, 1)
# array([[1],
#        [2],
#        [3],
#        [4],
#        [5]])

Now, add:

In [3]: x1_new + x2
Out[3]:
array([[ 6,  5,  4],
       [ 7,  6,  5],
       [ 8,  7,  6],
       [ 9,  8,  7],
       [10,  9,  8]])

Alternatively, you can also add new axis to the array x2:

In [6]: x2_new = x2[:, np.newaxis]    # x2[:, None]
In [7]: x2_new     # shape is (3, 1)
Out[7]: 
array([[5],
       [4],
       [3]])

Now, add:

In [8]: x1 + x2_new
Out[8]: 
array([[ 6,  7,  8,  9, 10],
       [ 5,  6,  7,  8,  9],
       [ 4,  5,  6,  7,  8]])

Note: Observe that we get the same result in both cases (but one being the transpose of the other).


Scenario-3: This is similar to scenario-1. But, you can use np.newaxis more than once to promote the array to higher dimensions. Such an operation is sometimes needed for higher order arrays (i.e. Tensors).

Example:

In [124]: arr = np.arange(5*5).reshape(5,5)

In [125]: arr.shape
Out[125]: (5, 5)

# promoting 2D array to a 5D array
In [126]: arr_5D = arr[np.newaxis, ..., np.newaxis, np.newaxis]    # arr[None, ..., None, None]

In [127]: arr_5D.shape
Out[127]: (1, 5, 5, 1, 1)

As an alternative, you can use numpy.expand_dims that has an intuitive axis kwarg.

# adding new axes at 1st, 4th, and last dimension of the resulting array
In [131]: newaxes = (0, 3, -1)
In [132]: arr_5D = np.expand_dims(arr, axis=newaxes)
In [133]: arr_5D.shape
Out[133]: (1, 5, 5, 1, 1)

More background on np.newaxis vs np.reshape

newaxis is also called as a pseudo-index that allows the temporary addition of an axis into a multiarray.

np.newaxis uses the slicing operator to recreate the array while numpy.reshape reshapes the array to the desired layout (assuming that the dimensions match; And this is must for a reshape to happen).

Example

In [13]: A = np.ones((3,4,5,6))
In [14]: B = np.ones((4,6))
In [15]: (A + B[:, np.newaxis, :]).shape     # B[:, None, :]
Out[15]: (3, 4, 5, 6)

In the above example, we inserted a temporary axis between the first and second axes of B (to use broadcasting). A missing axis is filled-in here using np.newaxis to make the broadcasting operation work.


General Tip: You can also use None in place of np.newaxis; These are in fact the same objects.

In [13]: np.newaxis is None
Out[13]: True

P.S. Also see this great answer: newaxis vs reshape to add dimensions

Send mail via CMD console

From Linux you can use 'swaks' which is available as an official packages on many distros including Debian/Ubuntu and Redhat/CentOS on EPEL:

swaks -f [email protected] -t [email protected] \
    --server mail.example.com

Why use def main()?

Without the main sentinel, the code would be executed even if the script were imported as a module.

Maven: Failed to retrieve plugin descriptor error

I had the same error. In my case I am using Netbeans 7.1.2, I am posting this because maybe someone end up here same as I did.

I tried to configure the proxy options from the GUI, but the documentation says that maven doesn't read those. So I checked the NetBeans FAQ here :

What mainly you have to do is create (if it does not exist) a settings.xml under

user.home/.m2/settings.xml

if you don't have it you can copy from

netbeans.home/java/maven/conf/settings.xml

then uncomment if you already have it otherwise just fill this section:

<proxies>
 <proxy>
   <active>true</active>
   <host>myproxy.host.net</host>
   <port>80</port>
 </proxy>
</proxies>

you have to check your proxy configuration and replace it there

How to show full object in Chrome console?

I made a function of the Trident D'Gao answer.

function print(obj) {
  console.log(JSON.stringify(obj, null, 4));
}

How to use it

print(obj);

How to return a table from a Stored Procedure?

In SQL Server 2008 you can use

http://www.sommarskog.se/share_data.html#tableparam

or else simple and same as common execution

CREATE PROCEDURE OrderSummary @MaxQuantity INT OUTPUT AS

SELECT Ord.EmployeeID, SummSales = SUM(OrDet.UnitPrice * OrDet.Quantity)
FROM Orders AS Ord
     JOIN [Order Details] AS OrDet ON (Ord.OrderID = OrDet.OrderID)
GROUP BY Ord.EmployeeID
ORDER BY Ord.EmployeeID

SELECT @MaxQuantity = MAX(Quantity) FROM [Order Details]

RETURN (SELECT SUM(Quantity) FROM [Order Details])
GO

I hopes its help to you

How to export settings?

Your user settings are in ~/Library/Application\ Support/Code/User.

If you're not concerned about syncing and it's a one time thing, you can just copy the files keybindings.json and settings.json to the corresponding folder on your new machine.

Your extensions are in the ~/.vscode folder. Most extensions aren't using any native bindings and they should be working properly when copied over. You can manually re-install those who do not.

Read Session Id using Javascript

The following can be used to retrieve JSESSIONID:

function getJSessionId(){
    var jsId = document.cookie.match(/JSESSIONID=[^;]+/);
    if(jsId != null) {
        if (jsId instanceof Array)
            jsId = jsId[0].substring(11);
        else
            jsId = jsId.substring(11);
    }
    return jsId;
}

jquery append external html file into my page

You can use jquery's load function here.

$("#your_element_id").load("file_name.html");

If you need more info, here is the link.

Node.js: get path from the request

simply call req.url. that should do the work. you'll get something like /something?bla=foo

How to set min-font-size in CSS

The font-min-size and font-max-size CSS properties were removed from the CSS Fonts Module Level 4 specification (and never implemented in browsers AFAIK). And the CSS Working Group replaced the CSS examples with font-size: clamp(...) which doesn't have the greatest browser support yet so we'll have to wait for browsers to support it. See example in https://developer.mozilla.org/en-US/docs/Web/CSS/clamp#Examples.

Find the number of columns in a table

Or use the sys.columns

--SQL 2005
SELECT  *
FROM    sys.columns
WHERE   OBJECT_NAME(object_id) = 'spt_values'
-- returns 6 rows = 6 columns

--SQL 2000
SELECT  *
FROM    syscolumns
WHERE   OBJECT_NAME(id) = 'spt_values'
-- returns 6 rows = 6 columns

SELECT  *
FROM    dbo.spt_values
    -- 6 columns indeed

Replacing column values in a pandas DataFrame

Using Series.map with Series.fillna

If your column contains more strings than only female and male, Series.map will fail in this case since it will return NaN for other values.

That's why we have to chain it with fillna:

Example why .map fails:

df = pd.DataFrame({'female':['male', 'female', 'female', 'male', 'other', 'other']})

   female
0    male
1  female
2  female
3    male
4   other
5   other
df['female'].map({'female': '1', 'male': '0'})

0      0
1      1
2      1
3      0
4    NaN
5    NaN
Name: female, dtype: object

For the correct method, we chain map with fillna, so we fill the NaN with values from the original column:

df['female'].map({'female': '1', 'male': '0'}).fillna(df['female'])

0        0
1        1
2        1
3        0
4    other
5    other
Name: female, dtype: object

How can I get zoom functionality for images?

You can try using the LayoutParams for this

public void zoom(boolean flag){
    if(flag){
        int width=40;
        int height=40;
    }
    else{
        int width=20;
        int height=20;
    }
    RelativeLayout.LayoutParams param=new RelativeLayout.LayoutParams(width,height); //use the parent layout of the ImageView;
    imageView.setLayoutParams(param); //imageView is the view which needs zooming.
}

ZoomIn = zoom(true); ZoomOut = zoom(false);

OpenCV & Python - Image too big to display

The other answers perform a fixed (width, height) resize. If you wanted to resize to a specific size while maintaining aspect ratio, use this

def ResizeWithAspectRatio(image, width=None, height=None, inter=cv2.INTER_AREA):
    dim = None
    (h, w) = image.shape[:2]

    if width is None and height is None:
        return image
    if width is None:
        r = height / float(h)
        dim = (int(w * r), height)
    else:
        r = width / float(w)
        dim = (width, int(h * r))

    return cv2.resize(image, dim, interpolation=inter)

Example

image = cv2.imread('img.png')
resize = ResizeWithAspectRatio(image, width=1280) # Resize by width OR
# resize = ResizeWithAspectRatio(image, height=1280) # Resize by height 

cv2.imshow('resize', resize)
cv2.waitKey()

Include an SVG (hosted on GitHub) in MarkDown

Update 2020: how they made it work while avoiding XSS attacks

GitHub appears to use two security approaches, this is a good article: https://digi.ninja/blog/svg_xss.php see also: https://security.stackexchange.com/questions/148507/how-to-prevent-xss-in-svg-file-upload

Update 2017

A GitHub dev is currently looking into this: https://github.com/github/markup/issues/556#issuecomment-306103203

Update 2014-12: GitHub now renders SVG on blob show, so I don't see any reason why not to render on README renderings:

Also note that that SVG does have an XSS attempt but it does not run: https://raw.githubusercontent.com/cirosantilli/test/2144a93333be144152e8b0d4144b77b211afce63/svg.svg

The billion laugh SVG does make Firefox 44 Freeze, but Chromium 48 is OK: https://github.com/cirosantilli/web-cheat/blob/master/svg-billion-laughs.svg

Petah mentioned that blobs are fine because the SVG is inside an iframe.

Possible rationale for GitHub not serving SVG images

The following questions asks about the risks of SVG in general: https://security.stackexchange.com/questions/11384/exploits-or-other-security-risks-with-svg-upload

How do I create a transparent Activity on Android?

Note 1:In Drawable folder create test.xml and copy the following code

   <?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >

    <stroke android:width="2dp" />

    <gradient
        android:angle="90"
        android:endColor="#29000000"
        android:startColor="#29000000" />

    <corners
        android:bottomLeftRadius="7dp"
        android:bottomRightRadius="7dp"
        android:topLeftRadius="7dp"
        android:topRightRadius="7dp" />

</shape>

// Note: Corners and shape is as per your requirement.

// Note 2:Create xml:

    <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/test"
        android:orientation="vertical" >

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1.09"
            android:gravity="center"
         android:background="@drawable/transperent_shape"
            android:orientation="vertical" >
     </LinearLayout>
    </LinearLayout>

How to force div to appear below not next to another?

what u can also do i place an extra "dummy" div before your last div.

Make it 1 px heigh and the width as much needed to cover the container div/body

This will make the last div appear under it, starting from the left.

Click toggle with jQuery

try changing this:

$(this).find(':checkbox').attr('checked', true ); 

to this:

$(this).find(':checkbox').attr('checked', 'checked'); 

Not 100% sure if that will do it, but I seem to recall having a similar problem. Good luck!