Programs & Examples On #Cffunction

Calling @Html.Partial to display a partial view belonging to a different controller

As GvS said, but I also find it useful to use strongly typed views so that I can write something like

@Html.Partial(MVC.Student.Index(), model)

without magic strings.

Convert XML String to Object

You can generate class as described above, or write them manually:

[XmlRoot("msg")]
public class Message
{
    [XmlElement("id")]
    public string Id { get; set; }
    [XmlElement("action")]
    public string Action { get; set; }
}

Then you can use ExtendedXmlSerializer to serialize and deserialize.

Instalation You can install ExtendedXmlSerializer from nuget or run the following command:

Install-Package ExtendedXmlSerializer

Serialization:

var serializer = new ConfigurationContainer().Create();
var obj = new Message();
var xml = serializer.Serialize(obj);

Deserialization

var obj2 = serializer.Deserialize<Message>(xml);

This serializer support:

  • Deserialization xml from standard XMLSerializer
  • Serialization class, struct, generic class, primitive type, generic list and dictionary, array, enum
  • Serialization class with property interface
  • Serialization circular reference and reference Id
  • Deserialization of old version of xml
  • Property encryption
  • Custom serializer
  • Support XmlElementAttribute and XmlRootAttribute
  • POCO - all configurations (migrations, custom serializer...) are outside the class

ExtendedXmlSerializer support .NET 4.5 or higher and .NET Core. You can integrate it with WebApi and AspCore.

const char* concatenation

If you don't know the size of the strings, you can do something like this:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main(){
    const char* q1 = "First String";
    const char* q2 = " Second String";

    char * qq = (char*) malloc((strlen(q1)+ strlen(q2))*sizeof(char));
    strcpy(qq,q1);
    strcat(qq,q2);

    printf("%s\n",qq);

    return 0;
}

How do I capture the output into a variable from an external process in PowerShell?

I tried the answers, but in my case I did not get the raw output. Instead it was converted to a PowerShell exception.

The raw result I got with:

$rawOutput = (cmd /c <command> 2`>`&1)

iOS for VirtualBox

You could try qemu, which is what the Android emulator uses. I believe it actually emulates the ARM hardware.

How to write a CSS hack for IE 11?

In the light of the evolving thread, I have updated the below:

IE 11 (and above..)

_:-ms-fullscreen, :root .foo { property:value; }

IE 10 and above

_:-ms-lang(x), .foo { property:value; }

or

@media all and (-ms-high-contrast: none), (-ms-high-contrast: active) {
   .foo{property:value;}
}

IE 10 only

_:-ms-lang(x), .foo { property:value\9; }

IE 9 and above

@media screen and (min-width:0\0) and (min-resolution: +72dpi) {
  //.foo CSS
  .foo{property:value;}
}

IE 9 and 10

@media screen and (min-width:0\0) {
    .foo /* backslash-9 removes.foo & old Safari 4 */
}

IE 9 only

@media screen and (min-width:0\0) and (min-resolution: .001dpcm) { 
 //.foo CSS
 .foo{property:value;}
}

IE 8,9 and 10

@media screen\0 {
    .foo {property:value;}
}

IE 8 Standards Mode Only

.foo { property /*\**/: value\9 }

IE 8

html>/**/body .foo {property:value;}

or

@media \0screen {
    .foo {property:value;}
}

IE 7

*+html .foo {property:value;}

or

*:first-child+html .foo {property:value;}

IE 6, 7 and 8

@media \0screen\,screen\9 {
    .foo {property:value;}
}

IE 6 and 7

@media screen\9 {
    .foo {property:value;}
}

or

.foo { *property:value;}

or

.foo { #property:value;}

IE 6, 7 and 8

@media \0screen\,screen\9 {
    .foo {property:value;}
}

IE 6

* html .foo {property:value;}

or

.foo { _property:value;}

Javascript alternatives

Modernizr

Modernizr runs quickly on page load to detect features; it then creates a JavaScript object with the results, and adds classes to the html element

User agent selection

Javascript:

var b = document.documentElement;
        b.setAttribute('data-useragent',  navigator.userAgent);
        b.setAttribute('data-platform', navigator.platform );
        b.className += ((!!('ontouchstart' in window) || !!('onmsgesturechange' in window))?' touch':'');

Adds (e.g) the below to html element:

data-useragent='Mozilla/5.0 (compatible; M.foo 9.0; Windows NT 6.1; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C)'
data-platform='Win32'

Allowing very targetted CSS selectors, e.g.:

html[data-useragent*='Chrome/13.0'] .nav{
    background:url(img/radial_grad.png) center bottom no-repeat;
}

Footnote

If possible, identify and fix any issue(s) without hacks. Support progressive enhancement and graceful degradation. However, this is an 'ideal world' scenario not always obtainable, as such- the above should help provide some good options.


Attribution / Essential Reading

How to plot a very simple bar chart (Python, Matplotlib) using input *.txt file?

First, what you are looking for is a column or bar diagram, not really a histogram. A histogram is made from a frequency distribution of a continuous variable that is separated into bins. Here you have a column against separate labels.

To make a bar diagram with matplotlib, use the matplotlib.pyplot.bar() method. Have a look at this page of the matplotlib documentation that explains very well with examples and source code how to do it.

If it is possible though, I would just suggest that for a simple task like this if you could avoid writing code that would be better. If you have any spreadsheet program this should be a piece of cake because that's exactly what they are for, and you won't have to 'reinvent the wheel'. The following is the plot of your data in Excel:

Bar diagram plot in Excel

I just copied your data from the question, used the text import wizard to put it in two columns, then I inserted a column diagram.

Unable to run Java GUI programs with Ubuntu

I too had OpenJDK on my Ubuntu machine:

$ java -version
java version "1.7.0_51"
OpenJDK Runtime Environment (IcedTea 2.4.4) (7u51-2.4.4-0ubuntu0.13.04.2)
OpenJDK 64-Bit Server VM (build 24.45-b08, mixed mode)

Replacing OpenJDK with the HotSpot VM works fine:

sudo apt-get autoremove openjdk-7-jre-headless

How to install the JDK on Ubuntu (Linux)

Python's equivalent of && (logical-and) in an if-statement

I'm getting an error in the IF conditional. What am I doing wrong?

There reason that you get a SyntaxError is that there is no && operator in Python. Likewise || and ! are not valid Python operators.

Some of the operators you may know from other languages have a different name in Python. The logical operators && and || are actually called and and or. Likewise the logical negation operator ! is called not.

So you could just write:

if len(a) % 2 == 0 and len(b) % 2 == 0:

or even:

if not (len(a) % 2 or len(b) % 2):

Some additional information (that might come in handy):

I summarized the operator "equivalents" in this table:

+------------------------------+---------------------+
|  Operator (other languages)  |  Operator (Python)  |
+==============================+=====================+
|              &&              |         and         |
+------------------------------+---------------------+
|              ||              |         or          |
+------------------------------+---------------------+
|              !               |         not         |
+------------------------------+---------------------+

See also Python documentation: 6.11. Boolean operations.

Besides the logical operators Python also has bitwise/binary operators:

+--------------------+--------------------+
|  Logical operator  |  Bitwise operator  |
+====================+====================+
|        and         |         &          |
+--------------------+--------------------+
|         or         |         |          |
+--------------------+--------------------+

There is no bitwise negation in Python (just the bitwise inverse operator ~ - but that is not equivalent to not).

See also 6.6. Unary arithmetic and bitwise/binary operations and 6.7. Binary arithmetic operations.

The logical operators (like in many other languages) have the advantage that these are short-circuited. That means if the first operand already defines the result, then the second operator isn't evaluated at all.

To show this I use a function that simply takes a value, prints it and returns it again. This is handy to see what is actually evaluated because of the print statements:

>>> def print_and_return(value):
...     print(value)
...     return value

>>> res = print_and_return(False) and print_and_return(True)
False

As you can see only one print statement is executed, so Python really didn't even look at the right operand.

This is not the case for the binary operators. Those always evaluate both operands:

>>> res = print_and_return(False) & print_and_return(True);
False
True

But if the first operand isn't enough then, of course, the second operator is evaluated:

>>> res = print_and_return(True) and print_and_return(False);
True
False

To summarize this here is another Table:

+-----------------+-------------------------+
|   Expression    |  Right side evaluated?  |
+=================+=========================+
| `True` and ...  |           Yes           |
+-----------------+-------------------------+
| `False` and ... |           No            |
+-----------------+-------------------------+
|  `True` or ...  |           No            |
+-----------------+-------------------------+
| `False` or ...  |           Yes           |
+-----------------+-------------------------+

The True and False represent what bool(left-hand-side) returns, they don't have to be True or False, they just need to return True or False when bool is called on them (1).

So in Pseudo-Code(!) the and and or functions work like these:

def and(expr1, expr2):
    left = evaluate(expr1)
    if bool(left):
        return evaluate(expr2)
    else:
        return left

def or(expr1, expr2):
    left = evaluate(expr1)
    if bool(left):
        return left
    else:
        return evaluate(expr2)

Note that this is pseudo-code not Python code. In Python you cannot create functions called and or or because these are keywords. Also you should never use "evaluate" or if bool(...).

Customizing the behavior of your own classes

This implicit bool call can be used to customize how your classes behave with and, or and not.

To show how this can be customized I use this class which again prints something to track what is happening:

class Test(object):
    def __init__(self, value):
        self.value = value

    def __bool__(self):
        print('__bool__ called on {!r}'.format(self))
        return bool(self.value)

    __nonzero__ = __bool__  # Python 2 compatibility

    def __repr__(self):
        return "{self.__class__.__name__}({self.value})".format(self=self)

So let's see what happens with that class in combination with these operators:

>>> if Test(True) and Test(False):
...     pass
__bool__ called on Test(True)
__bool__ called on Test(False)

>>> if Test(False) or Test(False):
...     pass
__bool__ called on Test(False)
__bool__ called on Test(False)

>>> if not Test(True):
...     pass
__bool__ called on Test(True)

If you don't have a __bool__ method then Python also checks if the object has a __len__ method and if it returns a value greater than zero. That might be useful to know in case you create a sequence container.

See also 4.1. Truth Value Testing.

NumPy arrays and subclasses

Probably a bit beyond the scope of the original question but in case you're dealing with NumPy arrays or subclasses (like Pandas Series or DataFrames) then the implicit bool call will raise the dreaded ValueError:

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

>>> import pandas as pd
>>> s = pd.Series([1,2,3])
>>> bool(s)
ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().
>>> s and s
ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

In these cases you can use the logical and function from NumPy which performs an element-wise and (or or):

>>> np.logical_and(np.array([False,False,True,True]), np.array([True, False, True, False]))
array([False, False,  True, False])
>>> np.logical_or(np.array([False,False,True,True]), np.array([True, False, True, False]))
array([ True, False,  True,  True])

If you're dealing just with boolean arrays you could also use the binary operators with NumPy, these do perform element-wise (but also binary) comparisons:

>>> np.array([False,False,True,True]) & np.array([True, False, True, False])
array([False, False,  True, False])
>>> np.array([False,False,True,True]) | np.array([True, False, True, False])
array([ True, False,  True,  True])

(1)

That the bool call on the operands has to return True or False isn't completely correct. It's just the first operand that needs to return a boolean in it's __bool__ method:

class Test(object):
    def __init__(self, value):
        self.value = value

    def __bool__(self):
        return self.value

    __nonzero__ = __bool__  # Python 2 compatibility

    def __repr__(self):
        return "{self.__class__.__name__}({self.value})".format(self=self)

>>> x = Test(10) and Test(10)
TypeError: __bool__ should return bool, returned int
>>> x1 = Test(True) and Test(10)
>>> x2 = Test(False) and Test(10)

That's because and actually returns the first operand if the first operand evaluates to False and if it evaluates to True then it returns the second operand:

>>> x1
Test(10)
>>> x2
Test(False)

Similarly for or but just the other way around:

>>> Test(True) or Test(10)
Test(True)
>>> Test(False) or Test(10)
Test(10)

However if you use them in an if statement the if will also implicitly call bool on the result. So these finer points may not be relevant for you.

mysql alphabetical order

You can use:

SELECT name FROM user WHERE name like 'b%' ORDER BY name

Get current date/time in seconds

var seconds = new Date().getTime() / 1000;

....will give you the seconds since midnight, 1 Jan 1970

Reference

Text editor to open big (giant, huge, large) text files

Tips and tricks

less

Why are you using editors to just look at a (large) file?

Under *nix or Cygwin, just use less. (There is a famous saying – "less is more, more or less" – because "less" replaced the earlier Unix command "more", with the addition that you could scroll back up.) Searching and navigating under less is very similar to Vim, but there is no swap file and little RAM used.

There is a Win32 port of GNU less. See the "less" section of the answer above.

Perl

Perl is good for quick scripts, and its .. (range flip-flop) operator makes for a nice selection mechanism to limit the crud you have to wade through.

For example:

$ perl -n -e 'print if ( 1000000 .. 2000000)' humongo.txt | less

This will extract everything from line 1 million to line 2 million, and allow you to sift the output manually in less.

Another example:

$ perl -n -e 'print if ( /regex one/ .. /regex two/)' humongo.txt | less

This starts printing when the "regular expression one" finds something, and stops when the "regular expression two" find the end of an interesting block. It may find multiple blocks. Sift the output...

logparser

This is another useful tool you can use. To quote the Wikipedia article:

logparser is a flexible command line utility that was initially written by Gabriele Giuseppini, a Microsoft employee, to automate tests for IIS logging. It was intended for use with the Windows operating system, and was included with the IIS 6.0 Resource Kit Tools. The default behavior of logparser works like a "data processing pipeline", by taking an SQL expression on the command line, and outputting the lines containing matches for the SQL expression.

Microsoft describes Logparser as a powerful, versatile tool that provides universal query access to text-based data such as log files, XML files and CSV files, as well as key data sources on the Windows operating system such as the Event Log, the Registry, the file system, and Active Directory. The results of the input query can be custom-formatted in text based output, or they can be persisted to more specialty targets like SQL, SYSLOG, or a chart.

Example usage:

C:\>logparser.exe -i:textline -o:tsv "select Index, Text from 'c:\path\to\file.log' where line > 1000 and line < 2000"
C:\>logparser.exe -i:textline -o:tsv "select Index, Text from 'c:\path\to\file.log' where line like '%pattern%'"

The relativity of sizes

100 MB isn't too big. 3 GB is getting kind of big. I used to work at a print & mail facility that created about 2% of U.S. first class mail. One of the systems for which I was the tech lead accounted for about 15+% of the pieces of mail. We had some big files to debug here and there.

And more...

Feel free to add more tools and information here. This answer is community wiki for a reason! We all need more advice on dealing with large amounts of data...

Is it better practice to use String.format over string Concatenation in Java?

You cannot compare String Concatenation and String.Format by the program above.

You may try this also be interchanging the position of using your String.Format and Concatenation in your code block like the below

public static void main(String[] args) throws Exception {      
  long start = System.currentTimeMillis();

  for( int i=0;i<1000000; i++){
    String s = String.format( "Hi %s; Hi to you %s",i, + i*2);
  }

  long end = System.currentTimeMillis();
  System.out.println("Format = " + ((end - start)) + " millisecond");
  start = System.currentTimeMillis();

  for( int i=0;i<1000000; i++){
    String s = "Hi " + i + "; Hi to you " + i*2;
  }

  end = System.currentTimeMillis();
  System.out.println("Concatenation = " + ((end - start)) + " millisecond") ;
}

You will be surprised to see that Format works faster here. This is since the intial objects created might not be released and there can be an issue with memory allocation and thereby the performance.

jQuery ajax request being block because Cross-Origin

Try with cURL request for cross-domain.

If you are working through third party APIs or getting data through CROSS-DOMAIN, it is always recommended to use cURL script (server side) which is more secure.

I always prefer cURL script.

How to start debug mode from command prompt for apache tomcat server?

On windows
$ catalina.bat jpda start
On Linux/Unix
$ catalina.sh jpda start

More info ----> https://cwiki.apache.org/confluence/display/TOMCAT/Developing

How do I retrieve query parameters in Spring Boot?

Use @RequestParam

@RequestMapping(value="user", method = RequestMethod.GET)
public @ResponseBody Item getItem(@RequestParam("data") String itemid){

    Item i = itemDao.findOne(itemid);              
    String itemName = i.getItemName();
    String price = i.getPrice();
    return i;
}

Getter and Setter of Model object in Angular 4

The way you declare the date property as an input looks incorrect but its hard to say if it's the only problem without seeing all your code. Rather than using @Input('date') declare the date property like so: private _date: string;. Also, make sure you are instantiating the model with the new keyword. Lastly, access the property using regular dot notation.

Check your work against this example from https://www.typescriptlang.org/docs/handbook/classes.html :

let passcode = "secret passcode";

class Employee {
    private _fullName: string;

    get fullName(): string {
        return this._fullName;
    }

    set fullName(newName: string) {
        if (passcode && passcode == "secret passcode") {
            this._fullName = newName;
        }
        else {
            console.log("Error: Unauthorized update of employee!");
        }
    }
}

let employee = new Employee();
employee.fullName = "Bob Smith";
if (employee.fullName) {
    console.log(employee.fullName);
}

And here is a plunker demonstrating what it sounds like you're trying to do: https://plnkr.co/edit/OUoD5J1lfO6bIeME9N0F?p=preview

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Sample jdbc connection class file. simply call the getConnection method when you want to get a connection. include related mysql-connector.jar

import java.sql.Connection;
import java.sql.DriverManager;


public class DBConnection {

    public Connection getConnection() {
        Connection con = null;

        String dbhost;
        String user;
        String password;
// get properties
dbhost="jdbc:mysql://localhost:3306/cardmaildb";
user="root";
password="123";

 System.out.println("S=======db Connecting======");

        try {
            Class.forName("com.mysql.jdbc.Driver");

            con = DriverManager.getConnection(dbhost, user, password);
            //if you are facing with SSl issue please try this 
            //con = DriverManager.getConnection("jdbc:mysql://192.168.23.100:3306/cardmaildb?useUnicode=yes&characterEncoding=UTF-8&useSSL=false",user, password);

        } catch (Exception e) {
            System.err.println("error in connection");
            e.printStackTrace();
        }
        System.out.println("E=======db Connecting======");
        return con;
    }

    public static void main(String[] args) {
        new DBConnection().getConnection();
    }
}

Getting the filenames of all files in a folder

You could do it like that:

File folder = new File("your/path");
File[] listOfFiles = folder.listFiles();

for (int i = 0; i < listOfFiles.length; i++) {
  if (listOfFiles[i].isFile()) {
    System.out.println("File " + listOfFiles[i].getName());
  } else if (listOfFiles[i].isDirectory()) {
    System.out.println("Directory " + listOfFiles[i].getName());
  }
}

Do you want to only get JPEG files or all files?

HTML - Arabic Support

Check you have <meta charset="utf-8"> inside head block.

Is there a “not in” operator in JavaScript for checking object properties?

It seems wrong to me to set up an if/else statement just to use the else portion...

Just negate your condition, and you'll get the else logic inside the if:

if (!(id in tutorTimes)) { ... }

Android device does not show up in adb list

Remove battery from phone, wait 10s, re-add it and try it again (alongside developer options etc.. in other questions)

I tried all other answers, but that was required in addition to the other suggestions for me.

SyntaxError: expected expression, got '<'

The main idea is that somehow HTML has been returned instead of Javascript.

The reason may be:

  • wrong paths
  • assets itself

It may be caused by wrong assets precompilation. In my case, I caught this error because of wrong encoding.

When I opened my application.js I saw application error Encoding::UndefinedConversionError at /assets/application.js

There was full backtrace of error formatted as HTML instead of Javasript.

Make sure that assets had been successfully precompiled.

git ignore exception

You can simply git add -f path/to/foo.dll.

.gitignore ignores only files for usual tracking and stuff like git add .

use localStorage across subdomains

This is how I solved it for my website. I redirected all the pages without www to www.site.com. This way, it will always take localstorage of www.site.com

Add the following to your .htacess, (create one if you already don't have it) in root directory

RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]

gulp command not found - error after installing gulp

Run npm install gulp -g

if you are using windows, please add the gulp's dir to PATH.

such like C:\Users\YOURNAME\AppData\Roaming\npm\node_modules\gulp

How to set UICollectionViewCell Width and Height programmatically

A simple way:

If you just need a simple fixed size:

class SizedCollectionView: UIICollectionView {
    override func common() {
        super.common()
        let l = UICollectionViewFlowLayout()
        l.itemSize = CGSize(width: 42, height: 42)
        collectionViewLayout = l
    }
}

That's all there is to it.

In storyboard, just change the class from UICollectionView to SizedCollectionView.

But !!!

Notice the base class there is "UI 'I' CollectionView". 'I' for Initializer.

It's not that easy to add an initializer to a collection view. Here's a common approach:

Collection view ... with initializer:

import UIKit

class UIICollectionView: UICollectionView {
    private var commoned: Bool = false
    
    override func didMoveToWindow() {
        super.didMoveToWindow()
        if window != nil && !commoned {
            commoned = true
            common()
        }
    }
    
    internal func common() {
    }
}

In most projects, you need "a collection view with an initializer". So you will probably anyway have UIICollectionView (note the extra I for Initializer!) in your project.

Executing Shell Scripts from the OS X Dock?

I think this thread may be helpful: http://forums.macosxhints.com/archive/index.php/t-70973.html

To paraphrase, you can rename it with the .command extension or create an AppleScript to run the shell.

Character Limit in HTML

There are 2 main solutions:

The pure HTML one:

<input type="text" id="Textbox" name="Textbox" maxlength="10" />

The JavaScript one (attach it to a onKey Event):

function limitText(limitField, limitNum) {
    if (limitField.value.length > limitNum) {
        limitField.value = limitField.value.substring(0, limitNum);
    } 
}

But anyway, there is no good solution. You can not adapt to every client's bad HTML implementation, it's an impossible fight to win. That's why it's far better to check it on the server side, with a PHP / Python / whatever script.

Java check if boolean is null

A boolean cannot be null in java.

A Boolean, however, can be null.

If a boolean is not assigned a value (say a member of a class) then it will be false by default.

Visual Studio build fails: unable to copy exe-file from obj\debug to bin\debug

When I have come across this problem it is to do with the Fact that the project I am trying to build is set as the Startup project in the solution making the .exe in the obj folder locked ( it also appears in your task manager,) right click another project in your solution and choose set startup project. This will release the lock, remove it from task manager and should let you build.

String comparison: InvariantCultureIgnoreCase vs OrdinalIgnoreCase?

Neither code is always better. They do different things, so they are good at different things.

InvariantCultureIgnoreCase uses comparison rules based on english, but without any regional variations. This is good for a neutral comparison that still takes into account some linguistic aspects.

OrdinalIgnoreCase compares the character codes without cultural aspects. This is good for exact comparisons, like login names, but not for sorting strings with unusual characters like é or ö. This is also faster because there are no extra rules to apply before comparing.

JQuery Validate Dropdown list

As we know jQuery validate plugin invalidates Select field when it has blank value. Why don't we set its value to blank when required.

Yes, you can validate select field with some predefined value.

$("#everything").validate({
    rules: {
        select_field:{
            required: {
                depends: function(element){
                    if('none' == $('#select_field').val()){
                        //Set predefined value to blank.
                        $('#select_field').val('');
                    }
                    return true;
                }
            }
        }
    }
});

We can set blank value for select field but in some case we can't. For Ex: using a function that generates Dropdown field for you and you don't have control over it.

I hope it helps as it helps me.

creating charts with angularjs

Did you try D3.js? Here is a good example.

Matplotlib: Specify format of floats for tick labels

format labels using lambda function

enter image description here 3x the same plot with differnt y-labeling

Minimal example

import numpy as np
import matplotlib as mpl
import matplotlib.pylab as plt
from matplotlib.ticker import FormatStrFormatter

fig, axs = mpl.pylab.subplots(1, 3)

xs = np.arange(10)
ys = 1 + xs ** 2 * 1e-3

axs[0].set_title('default y-labeling')
axs[0].scatter(xs, ys)
axs[1].set_title('custom y-labeling')
axs[1].scatter(xs, ys)
axs[2].set_title('x, pos arguments')
axs[2].scatter(xs, ys)


fmt = lambda x, pos: '1+ {:.0f}e-3'.format((x-1)*1e3, pos)
axs[1].yaxis.set_major_formatter(mpl.ticker.FuncFormatter(fmt))

fmt = lambda x, pos: 'x={:f}\npos={:f}'.format(x, pos)
axs[2].yaxis.set_major_formatter(mpl.ticker.FuncFormatter(fmt))

You can also use 'real'-functions instead of lambdas, of course. https://matplotlib.org/3.1.1/gallery/ticks_and_spines/tick-formatters.html

How can I get all element values from Request.Form without specifying exactly which one with .GetValues("ElementIdName")

Here is a way to do it without adding an ID to the form elements.

<form method="post">
    ...
    <select name="List">
        <option value="1">Test1</option>
        <option value="2">Test2</option>
    </select>
    <select name="List">
        <option value="3">Test3</option>
        <option value="4">Test4</option>
    </select>
    ...
</form>

public ActionResult OrderProcessor()
{
    string[] ids = Request.Form.GetValues("List");
}

Then ids will contain all the selected option values from the select lists. Also, you could go down the Model Binder route like so:

public class OrderModel
{
    public string[] List { get; set; }
}

public ActionResult OrderProcessor(OrderModel model)
{
    string[] ids = model.List;
}

Hope this helps.

Retrieving Dictionary Value Best Practices

TryGetValue is slightly faster, because FindEntry will only be called once.

How much faster? It depends on the dataset at hand. When you call the Contains method, Dictionary does an internal search to find its index. If it returns true, you need another index search to get the actual value. When you use TryGetValue, it searches only once for the index and if found, it assigns the value to your variable.

FYI: It's not actually catching an error.

It's calling:

public bool TryGetValue(TKey key, out TValue value)
{
    int index = this.FindEntry(key);
    if (index >= 0)
    {
        value = this.entries[index].value;
        return true;
    }
    value = default(TValue);
    return false;
}

ContainsKey is this:

public bool ContainsKey(TKey key)
{
    return (this.FindEntry(key) >= 0);
}

python dict to numpy structured array

Even more simple if you accept using pandas :

import pandas
result = {0: 1.1181753789488595, 1: 0.5566080288678394, 2: 0.4718269778030734, 3: 0.48716683119447185, 4: 1.0, 5: 0.1395076201641266, 6: 0.20941558441558442}
df = pandas.DataFrame(result, index=[0])
print df

gives :

          0         1         2         3  4         5         6
0  1.118175  0.556608  0.471827  0.487167  1  0.139508  0.209416

batch file to copy files to another location?

It's easy to copy a folder in a batch file.

 @echo off
 set src_folder = c:\whatever\*.*
 set dst_folder = c:\foo
 xcopy /S/E/U %src_folder% %dst_folder%

And you can add that batch file to your Windows login script pretty easily (assuming you have admin rights on the machine). Just go to the "User Manager" control panel, choose properties for your user, choose profile and set a logon script.

How you get to the user manager control panel depends on which version of Windows you run. But right clicking on My Computer and choosing manage and then choosing Local users and groups works for most versions.

The only sticky bit is "when the folder is updated". This sounds like a folder watcher, which you can't do in a batch file, but you can do pretty easily with .NET.

Lodash - difference between .extend() / .assign() and .merge()

If you want a deep copy without override while retaining the same obj reference

obj = _.assign(obj, _.merge(obj, [source]))

How to completely remove borders from HTML table

<table cellspacing="0" cellpadding="0">

And in css:

table {border: none;}

EDIT: As iGEL noted, this solution is officially deprecated (still works though), so if you are starting from scratch, you should go with the jnpcl's border-collapse solution.

I actually quite dislike this change so far (don't work with tables that often). It makes some tasks bit more complicated. E.g. when you want to include two different borders in same place (visually), while one being TOP for one row, and second being BOTTOM for other row. They will collapse (= only one of them will be shown). Then you have to study how is border's "priority" calculated and what border styles are "stronger" (double vs. solid etc.).

I did like this:

<table cellspacing="0" cellpadding="0">
  <tr>
    <td class="first">first row</td>
  </tr>
  <tr>
    <td class="second">second row</td>
  </tr>
</table>

----------

.first {border-bottom:1px solid #EEE;}
.second {border-top:1px solid #CCC;}

Now, with border collapse, this won't work as there is always one border removed. I have to do it in some other way (there are more solutions ofc). One possibility is using CSS3 with box-shadow:

<table class="tab">
  <tr>
    <td class="first">first row</td>
  </tr>
  <tr>
    <td class="second">second row</td>
  </tr>
</table>???

<style>
.tab {border-collapse:collapse;}
.tab .first {border-bottom:1px solid #EEE;}
.tab .second {border-top:1px solid #CCC;box-shadow: inset 0 1px 0 #CCC;}?
</style>

You could also use something like "groove|ridge|inset|outset" border style with just a single border. But for me, this is not optimal, because I can't control both colors.

Maybe there is some simple and nice solution for collapsing borders, but I haven't seen it yet and I honestly haven't spent much time on it. Maybe someone here will be able to show me/us ;)

How do I do a Date comparison in Javascript?

function fn_DateCompare(DateA, DateB) {     // this function is good for dates > 01/01/1970

    var a = new Date(DateA);
    var b = new Date(DateB);

    var msDateA = Date.UTC(a.getFullYear(), a.getMonth()+1, a.getDate());
    var msDateB = Date.UTC(b.getFullYear(), b.getMonth()+1, b.getDate());

    if (parseFloat(msDateA) < parseFloat(msDateB))
      return -1;  // lt
    else if (parseFloat(msDateA) == parseFloat(msDateB))
      return 0;  // eq
    else if (parseFloat(msDateA) > parseFloat(msDateB))
      return 1;  // gt
    else
      return null;  // error
}

using href links inside <option> tag

(I don't have enough reputation to comment on toscho's answer.)

I have no experience with screen readers and I'm sure your points are valid.

However as far as using a keyboard to manipulate selects, it is trivial to select any option by using the keyboard:

TAB to the control

SPACE to open the select list

UP or DOWN arrows to scroll to the desired list item

ENTER to select the desired item

Only on ENTER does the onchange or (JQuery .change()) event fire.

While I personally would not use a form control for simple menus, there are many web applications that use form controls to change the presentation of the page (eg., sort order.) These can be implemented either by AJAX to load new content into the page, or, in older implementations, by triggering new page loads, which is essentially a page link.

IMHO these are valid uses of a form control.

What is the difference between POST and GET?

GET and POST are two different types of HTTP requests.

According to Wikipedia:

GET requests a representation of the specified resource. Note that GET should not be used for operations that cause side-effects, such as using it for taking actions in web applications. One reason for this is that GET may be used arbitrarily by robots or crawlers, which should not need to consider the side effects that a request should cause.

and

POST submits data to be processed (e.g., from an HTML form) to the identified resource. The data is included in the body of the request. This may result in the creation of a new resource or the updates of existing resources or both.

So essentially GET is used to retrieve remote data, and POST is used to insert/update remote data.


HTTP/1.1 specification (RFC 2616) section 9 Method Definitions contains more information on GET and POST as well as the other HTTP methods, if you are interested.

In addition to explaining the intended uses of each method, the spec also provides at least one practical reason for why GET should only be used to retrieve data:

Authors of services which use the HTTP protocol SHOULD NOT use GET based forms for the submission of sensitive data, because this will cause this data to be encoded in the Request-URI. Many existing servers, proxies, and user agents will log the request URI in some place where it might be visible to third parties. Servers can use POST-based form submission instead


Finally, an important consideration when using GET for AJAX requests is that some browsers - IE in particular - will cache the results of a GET request. So if you, for example, poll using the same GET request you will always get back the same results, even if the data you are querying is being updated server-side. One way to alleviate this problem is to make the URL unique for each request by appending a timestamp.

post checkbox value

There are many links that lets you know how to handle post values from checkboxes in php. Look at this link: http://www.html-form-guide.com/php-form/php-form-checkbox.html

Single check box

HTML code:

<form action="checkbox-form.php" method="post">
    Do you need wheelchair access?
    <input type="checkbox" name="formWheelchair" value="Yes" />
    <input type="submit" name="formSubmit" value="Submit" />
</form>

PHP Code:

<?php

if (isset($_POST['formWheelchair']) && $_POST['formWheelchair'] == 'Yes') 
{
    echo "Need wheelchair access.";
}
else
{
    echo "Do not Need wheelchair access.";
}    

?>

Check box group

<form action="checkbox-form.php" method="post">
    Which buildings do you want access to?<br />
    <input type="checkbox" name="formDoor[]" value="A" />Acorn Building<br />
    <input type="checkbox" name="formDoor[]" value="B" />Brown Hall<br />
    <input type="checkbox" name="formDoor[]" value="C" />Carnegie Complex<br />
    <input type="checkbox" name="formDoor[]" value="D" />Drake Commons<br />
    <input type="checkbox" name="formDoor[]" value="E" />Elliot House

    <input type="submit" name="formSubmit" value="Submit" />
 /form>

<?php
  $aDoor = $_POST['formDoor'];
  if(empty($aDoor)) 
  {
    echo("You didn't select any buildings.");
  } 
  else
  {
    $N = count($aDoor);

    echo("You selected $N door(s): ");
    for($i=0; $i < $N; $i++)
    {
      echo($aDoor[$i] . " ");
    }
  }
?>

VERR_VMX_MSR_VMXON_DISABLED when starting an image from Oracle virtual box

There is an option in the Virtual Box itself. If you look in the Oracle VM Virtual Box Manager. Select the Virtual Box you want to start. Go to System, the second from above item in the right pane. In System go to the third tab called acceleration. In that tab the first check box is called something like: 'VT-x/AMD-V' (I have the Dutch version, so I don't know the exact string) UNCHECK And then start. That worked for me.

I also got this problem after an upgrade. And I did not have the problem before. But I fail to see the exact connection between the update and the check/unchecking of that option.

By the way, I have no idea where the hell that 'virtualization tab' should be in my 'BIOS'. Maybe I was looking in my PC's BIOS not the System page here which is the BIOS of the VM Machine maybe and that is what you meant Veer7? If it was, it was pretty unclear you meant this. Maybe it's because I have OVM in Dutch not English. But there was nothing called BIOS in the Oracle VM Virtual Box Manager I could find.

Javascript for "Add to Home Screen" on iPhone?

The only way to add any book marks in MobileSafari (including ones on the home screen) is with the builtin UI, and that Apples does not provide anyway to do this from scripts within a page. In fact, I am pretty sure there is no mechanism for doing this on the desktop version of Safari either.

Java 8 Lambda function that throws exception?

Sneaky throw idiom enables bypassing CheckedException of Lambda expression. Wrapping a CheckedException in a RuntimeException is not good for strict error handling.

It can be used as a Consumer function used in a Java collection.

Here is a simple and improved version of jib's answer.

import static Throwing.rethrow;

@Test
public void testRethrow() {
    thrown.expect(IOException.class);
    thrown.expectMessage("i=3");

    Arrays.asList(1, 2, 3).forEach(rethrow(e -> {
        int i = e.intValue();
        if (i == 3) {
            throw new IOException("i=" + i);
        }
    }));
}

This just wrapps the lambda in a rethrow. It makes CheckedException rethrow any Exception that was thrown in your lambda.

public final class Throwing {
    private Throwing() {}

    @Nonnull
    public static <T> Consumer<T> rethrow(@Nonnull final ThrowingConsumer<T> consumer) {
        return consumer;
    }

    /**
     * The compiler sees the signature with the throws T inferred to a RuntimeException type, so it
     * allows the unchecked exception to propagate.
     * 
     * http://www.baeldung.com/java-sneaky-throws
     */
    @SuppressWarnings("unchecked")
    @Nonnull
    public static <E extends Throwable> void sneakyThrow(@Nonnull Throwable ex) throws E {
        throw (E) ex;
    }

}

Find a complete code and unit tests here.

Get current language in CultureInfo

This is what i used:

var culture = System.Globalization.CultureInfo.CurrentCulture;

and it's working :)

Refresh a page using PHP

You sure can refresh a page periodically using PHP:

<?php
    header("refresh: 3;");
?>

This will refresh the page every three seconds.

How to install XNA game studio on Visual Studio 2012?

On codeplex was released new XNA Extension for Visual Studio 2012/2013. You can download it from: https://msxna.codeplex.com/releases

R adding days to a date

Use +

> as.Date("2001-01-01") + 45
[1] "2001-02-15"

How to quit a java app from within the program

The answer is System.exit(), but not a good thing to do as this aborts the program. Any cleaning up, destroy that you intend to do will not happen.

Unit tests vs Functional tests

Unit Tests are written from a programmers or developers perspective. They are made to ensure that a particular method (or a unit) of a class performs a set of specific tasks.

Functional Tests are written from the user's perspective. They ensure that the system is functioning as users are expecting it to.

HTTP Basic Authentication - what's the expected web browser experience?

Have you tried ?

curl somesite.com --user username:password

Git Clone from GitHub over https with two-factor authentication

Find out how to fix this here:

https://github.com/blog/1614-two-factor-authentication#how-does-it-work-for-command-line-git

How does it work for command-line Git?

If you are using SSH for Git authentication, rest easy: you don't need to do anything. If you are using HTTPS Git, instead of entering your password, enter a personal access token. These can be created by going to your personal access tokens page.

Common HTTPclient and proxy

Here is how to do that with the last version of HTTPClient (4.3.4)

    CloseableHttpClient httpclient = HttpClients.createDefault();
    try {
        HttpHost target = new HttpHost("localhost", 443, "https");
        HttpHost proxy = new HttpHost("127.0.0.1", 8080, "http");

        RequestConfig config = RequestConfig.custom()
                .setProxy(proxy)
                .build();
        HttpGet request = new HttpGet("/");
        request.setConfig(config);

        System.out.println("Executing request " + request.getRequestLine() + " to " + target + " via " + proxy);

        CloseableHttpResponse response = httpclient.execute(target, request);
        try {
            System.out.println("----------------------------------------");
            System.out.println(response.getStatusLine());
            EntityUtils.consume(response.getEntity());
        } finally {
            response.close();
        }
    } finally {
        httpclient.close();
    }

Get checkbox value in jQuery

$('.class[value=3]').prop('checked', true);

How to scroll the window using JQuery $.scrollTo() function

$('html, body').animate({scrollTop: $("#page").offset().top}, 2000);

Python: "TypeError: __str__ returned non-string" but still prints to output?

Just Try this:

def __str__(self):
    return f'Memo={self.memo}, Tag={self.tags}'

Determining type of an object in ruby

Oftentimes in Ruby, you don't actually care what the object's class is, per se, you just care that it responds to a certain method. This is known as Duck Typing and you'll see it in all sorts of Ruby codebases.

So in many (if not most) cases, its best to use Duck Typing using #respond_to?(method):

object.respond_to?(:to_i)

Java system properties and environment variables

how to open *.sdf files?

Try LINQPad, it works for SQL Server, MySQL, SQLite and also SDF (SQL CE 4.0). Best of all it's free!

LINQPad

Steps with version 4.35.1:

  1. click 'Add Connection'

  2. Click Next with 'Build data context automatically' and 'Default(LINQ to SQL)' selected.

  3. Under 'Provider' choose 'SQL CE 4.0'.

  4. Under 'Database' with 'Attach database file' selected, choose 'Browse' to select your .sdf file.

  5. Click 'OK'.

  6. Voila! It should show the tables in .sdf and be able to query it via right clicking the table or writing LINQ code in your favorite .NET language or even SQL. How cool is that?

How to Customize the time format for Python logging?

if using logging.config.fileConfig with a configuration file use something like:

[formatter_simpleFormatter]
format=%(asctime)s - %(name)s - %(levelname)s - %(message)s
datefmt=%Y-%m-%d %H:%M:%S

Add shadow to custom shape on Android

I would suggest a small improvement to Bruce's solution which is to prevent overdrawing the same shape on top of each other and to simply use stroke instead of solid. It would look like this:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- Drop Shadow Stack -->
    <item>
        <shape>
            <padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
            <stroke android:color="#02000000" android:width="1dp"  />
            <corners android:radius="8dp" />
        </shape>
    </item>
    <item>
        <shape>
            <padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
            <stroke android:color="#05000000" android:width="1dp" />
            <corners android:radius="7dp" />
        </shape>
    </item>
    <item>
        <shape>
            <padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
            <stroke android:color="#10000000" android:width="1dp" />
            <corners android:radius="6dp" />
        </shape>
    </item>
    <item>
        <shape>
            <padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
            <stroke android:color="#15000000" android:width="1dp" />
            <corners android:radius="5dp" />
        </shape>
    </item>
    <item>
        <shape>
            <padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
            <stroke android:color="#20000000" android:width="1dp" />
            <corners android:radius="4dp" />
        </shape>
    </item>
    <item>
        <shape>
            <padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
            <stroke android:color="#25000000" android:width="1dp" />
            <corners android:radius="3dp" />
        </shape>
    </item>
    <item>
        <shape>
            <padding android:top="1dp" android:right="1dp" android:bottom="1dp" android:left="1dp" />
            <stroke android:color="#30000000" android:width="1dp" />
            <corners android:radius="3dp" />
        </shape>
    </item>

    <!-- Background -->
    <item>
        <shape>
            <solid android:color="#FFF" />
            <corners android:radius="3dp" />
        </shape>
    </item>
</layer-list>

screenshot of the rendering of the shadow Lastly I wanted to point out for people who would like a shadow in a specific direction that all you have to do is set the top, bottom, left or right to 0dp (for a solid line) or -1dp (for nothing)

Node.js Mongoose.js string to ObjectId function

Judging from the comments, you are looking for:

mongoose.mongo.BSONPure.ObjectID.isValid

Or

mongoose.Types.ObjectId.isValid

Remove tracking branches no longer on remote

I have written a Python script using GitPython to do delete local branches which don't exist on remote.

    import git
    import subprocess
    from git.exc import GitCommandError
    import os

    def delete_merged_branches():
        current_dir = input("Enter repository directory:")
        repo = git.Repo(current_dir)
        git_command = git.Git(current_dir)

        # fetch the remote with prune, this will delete the remote references in local.
        for remote in repo.remotes:
            remote.fetch(prune=True)
        
        local_branches = [branch.name for branch in repo.branches]
        deleted_branches = []

        # deleted_branches are the branches which are deleted on remote but exists on local.
        for branch in local_branches:
            try:
                remote_name = 'origin/'+ branch
                repo.git.checkout(remote_name)
            except GitCommandError:
            # if the remote reference is not present, it means the branch is deleted on remote.
                deleted_branches.append(branch)
            
        for branch in deleted_branches:
            print("Deleting branch:"+branch)
            git_command.execute(["git", "branch", "-D",branch])

    
        # clean up the work flow.
        repo.git.checkout('master')
        repo.git.pull()

    if __name__ == '__main__':
        delete_merged_branches()

Hope someone finds it useful, please add comments if I missed anything.

Upgrade python without breaking yum

I have written a quick guide on how to install the latest versions of Python 2 and Python 3 on CentOS 6 and CentOS 7. It currently covers Python 2.7.13 and Python 3.6.0:

# Start by making sure your system is up-to-date:
yum update
# Compilers and related tools:
yum groupinstall -y "development tools"
# Libraries needed during compilation to enable all features of Python:
yum install -y zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel expat-devel
# If you are on a clean "minimal" install of CentOS you also need the wget tool:
yum install -y wget

The next steps depend on the version of Python you're installing.

For Python 2.7.14:

wget http://python.org/ftp/python/2.7.14/Python-2.7.14.tar.xz
tar xf Python-2.7.14.tar.xz
cd Python-2.7.14
./configure --prefix=/usr/local --enable-unicode=ucs4 --enable-shared LDFLAGS="-Wl,-rpath /usr/local/lib"
make && make altinstall

# Strip the Python 2.7 binary:
strip /usr/local/lib/libpython2.7.so.1.0

For Python 3.6.3:

wget http://python.org/ftp/python/3.6.3/Python-3.6.3.tar.xz
tar xf Python-3.6.3.tar.xz
cd Python-3.6.3
./configure --prefix=/usr/local --enable-shared LDFLAGS="-Wl,-rpath /usr/local/lib"
make && make altinstall

# Strip the Python 3.6 binary:
strip /usr/local/lib/libpython3.6m.so.1.0

To install Pip:

# First get the script:
wget https://bootstrap.pypa.io/get-pip.py

# Then execute it using Python 2.7 and/or Python 3.6:
python2.7 get-pip.py
python3.6 get-pip.py

# With pip installed you can now do things like this:
pip2.7 install [packagename]
pip2.7 install --upgrade [packagename]
pip2.7 uninstall [packagename]

You are not supposed to change the system version of Python because it will break the system (as you found out). Installing other versions works fine as long as you leave the original system version alone. This can be accomplished by using a custom prefix (for example /usr/local) when running configure, and using make altinstall (instead of the normal make install) when installing your build of Python.

Having multiple versions of Python available is usually not a big problem as long as you remember to type the full name including the version number (for example "python2.7" or "pip2.7"). If you do all your Python work from a virtualenv the versioning is handled for you, so make sure you install and use virtualenv!

Rebuild or regenerate 'ic_launcher.png' from images in Android Studio

You can create an icon using this website https://romannurik.github.io/AndroidAssetStudio/index.html.

Download the icon, go to File Explorer - where your projects are saved, the default path is C:\Users\Your Name\AndroidStudioProjects\Project Name\app\src\main\res\

and copy the folders you downloaded to the res folder.

Global constants file in Swift

Although I prefer @Francescu's way (using a struct with static properties), you can also define global constants and variables:

let someNotification = "TEST"

Note however that differently from local variables/constants and class/struct properties, globals are implicitly lazy, which means they are initialized when they are accessed for the first time.

Suggested reading: Global and Local Variables, and also Global variables in Swift are not variables

How to download the latest artifact from Artifactory repository?

With recent versions of artifactory, you can query this through the api.

https://www.jfrog.com/confluence/display/RTF/Artifactory+REST+API#ArtifactoryRESTAPI-RetrieveLatestArtifact

If you have a maven artifact with 2 snapshots

name => 'com.acme.derp'
version => 0.1.0
repo name => 'foo'
snapshot 1 => derp-0.1.0-20161121.183847-3.jar
snapshot 2 => derp-0.1.0-20161122.00000-0.jar

Then the full paths would be

https://artifactory.example.com/artifactory/foo/com/acme/derp/0.1.0-SNAPSHOT/derp-0.1.0-20161121.183847-3.jar

and

https://artifactory.example.com/artifactory/foo/com/acme/derp/0.1.0-SNAPSHOT/derp-0.1.0-20161122.00000-0.jar

You would fetch the latest like so:

curl https://artifactory.example.com/artifactory/foo/com/acme/derp/0.1.0-SNAPSHOT/derp-0.1.0-SNAPSHOT.jar

Can I export a variable to the environment from a bash script without sourcing it?

Found an interesting and neat way to export environment variables from a file:

in env.vars:

foo=test

test script:

eval `cat env.vars`
echo $foo         # => test
sh -c 'echo $foo' # => 

export eval `cat env.vars`
echo $foo         # => test
sh -c 'echo $foo' # => test

# a better one. "--" stops processing options, 
# key=value list given as params
export -- `cat env.vars`
echo $foo         # => test
sh -c 'echo $foo' # => test

Collection was modified; enumeration operation may not execute in ArrayList

I agree with several of the points I've read in this post and I've incorporated them into my solution to solve the exact same issue as the original posting.

That said, the comments I appreciated are:

  • "unless you are using .NET 1.0 or 1.1, use List<T> instead of ArrayList. "

  • "Also, add the item(s) to be deleted to a new list. Then go through and delete those items." .. in my case I just created a new List and the populated it with the valid data values.

e.g.

private List<string> managedLocationIDList = new List<string>();
string managedLocationIDs = ";1321;1235;;" // user input, should be semicolon seperated list of values

managedLocationIDList.AddRange(managedLocationIDs.Split(new char[] { ';' }));
List<string> checkLocationIDs = new List<string>();

// Remove any duplicate ID's and cleanup the string holding the list if ID's
Functions helper = new Functions();
checkLocationIDs = helper.ParseList(managedLocationIDList);

...
public List<string> ParseList(List<string> checkList)
{
    List<string> verifiedList = new List<string>();

    foreach (string listItem in checkList)
    if (!verifiedList.Contains(listItem.Trim()) && listItem != string.Empty)
        verifiedList.Add(listItem.Trim());

    verifiedList.Sort();
    return verifiedList;
}        

What are the pros and cons of parquet format compared to other formats?

I think the main difference I can describe relates to record oriented vs. column oriented formats. Record oriented formats are what we're all used to -- text files, delimited formats like CSV, TSV. AVRO is slightly cooler than those because it can change schema over time, e.g. adding or removing columns from a record. Other tricks of various formats (especially including compression) involve whether a format can be split -- that is, can you read a block of records from anywhere in the dataset and still know it's schema? But here's more detail on columnar formats like Parquet.

Parquet, and other columnar formats handle a common Hadoop situation very efficiently. It is common to have tables (datasets) having many more columns than you would expect in a well-designed relational database -- a hundred or two hundred columns is not unusual. This is so because we often use Hadoop as a place to denormalize data from relational formats -- yes, you get lots of repeated values and many tables all flattened into a single one. But it becomes much easier to query since all the joins are worked out. There are other advantages such as retaining state-in-time data. So anyway it's common to have a boatload of columns in a table.

Let's say there are 132 columns, and some of them are really long text fields, each different column one following the other and use up maybe 10K per record.

While querying these tables is easy with SQL standpoint, it's common that you'll want to get some range of records based on only a few of those hundred-plus columns. For example, you might want all of the records in February and March for customers with sales > $500.

To do this in a row format the query would need to scan every record of the dataset. Read the first row, parse the record into fields (columns) and get the date and sales columns, include it in your result if it satisfies the condition. Repeat. If you have 10 years (120 months) of history, you're reading every single record just to find 2 of those months. Of course this is a great opportunity to use a partition on year and month, but even so, you're reading and parsing 10K of each record/row for those two months just to find whether the customer's sales are > $500.

In a columnar format, each column (field) of a record is stored with others of its kind, spread all over many different blocks on the disk -- columns for year together, columns for month together, columns for customer employee handbook (or other long text), and all the others that make those records so huge all in their own separate place on the disk, and of course columns for sales together. Well heck, date and months are numbers, and so are sales -- they are just a few bytes. Wouldn't it be great if we only had to read a few bytes for each record to determine which records matched our query? Columnar storage to the rescue!

Even without partitions, scanning the small fields needed to satisfy our query is super-fast -- they are all in order by record, and all the same size, so the disk seeks over much less data checking for included records. No need to read through that employee handbook and other long text fields -- just ignore them. So, by grouping columns with each other, instead of rows, you can almost always scan less data. Win!

But wait, it gets better. If your query only needed to know those values and a few more (let's say 10 of the 132 columns) and didn't care about that employee handbook column, once it had picked the right records to return, it would now only have to go back to the 10 columns it needed to render the results, ignoring the other 122 of the 132 in our dataset. Again, we skip a lot of reading.

(Note: for this reason, columnar formats are a lousy choice when doing straight transformations, for example, if you're joining all of two tables into one big(ger) result set that you're saving as a new table, the sources are going to get scanned completely anyway, so there's not a lot of benefit in read performance, and because columnar formats need to remember more about the where stuff is, they use more memory than a similar row format).

One more benefit of columnar: data is spread around. To get a single record, you can have 132 workers each read (and write) data from/to 132 different places on 132 blocks of data. Yay for parallelization!

And now for the clincher: compression algorithms work much better when it can find repeating patterns. You could compress AABBBBBBCCCCCCCCCCCCCCCC as 2A6B16C but ABCABCBCBCBCCCCCCCCCCCCCC wouldn't get as small (well, actually, in this case it would, but trust me :-) ). So once again, less reading. And writing too.

So we read a lot less data to answer common queries, it's potentially faster to read and write in parallel, and compression tends to work much better.

Columnar is great when your input side is large, and your output is a filtered subset: from big to little is great. Not as beneficial when the input and outputs are about the same.

But in our case, Impala took our old Hive queries that ran in 5, 10, 20 or 30 minutes, and finished most in a few seconds or a minute.

Hope this helps answer at least part of your question!

Increment a value in Postgres

UPDATE totals 
   SET total = total + 1
WHERE name = 'bill';

If you want to make sure the current value is indeed 203 (and not accidently increase it again) you can also add another condition:

UPDATE totals 
   SET total = total + 1
WHERE name = 'bill'
  AND total = 203;

Unable to find the requested .Net Framework Data Provider. It may not be installed. - when following mvc3 asp.net tutorial

I was able to solve a problem similar to this in Visual Studio 2010 by using NuGet.

Go to Tools > Library Package Manager > Manage NuGet Packages For Solution...

In the dialog, search for "EntityFramework.SqlServerCompact". You'll find a package with the description "Allows SQL Server Compact 4.0 to be used with Entity Framework." Install this package.

An element similar to the following will be inserted in your web.config:

<entityFramework>
  <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlCeConnectionFactory, EntityFramework">
    <parameters>
      <parameter value="System.Data.SqlServerCe.4.0" />
    </parameters>
  </defaultConnectionFactory>
</entityFramework>

How can I select all options of multi-select select box on click?

I'm able to make it in a native way @ jsfiddle. Hope it will help.

Post improved answer when it work, and help others.

$(function () { 

    $(".example").multiselect({
                checkAllText : 'Select All',
            uncheckAllText : 'Deselect All',
            selectedText: function(numChecked, numTotal, checkedItems){
              return numChecked + ' of ' + numTotal + ' checked';
            },
            minWidth: 325
    });
    $(".example").multiselect("checkAll");    

});

http://jsfiddle.net/shivasakthi18/25uvnyra/

How to set upload_max_filesize in .htaccess?

What to do to correct this is create a file called php.ini and save it in the same location as your .htaccess file and enter the following code instead:

upload_max_filesize = "250M"
post_max_size = "250M"

Wait for Angular 2 to load/resolve model before rendering view/template

EDIT: The angular team has released the @Resolve decorator. It still needs some clarification, in how it works, but until then I'll take someone else's related answer here, and provide links to other sources:


EDIT: This answer works for Angular 2 BETA only. Router is not released for Angular 2 RC as of this edit. Instead, when using Angular 2 RC, replace references to router with router-deprecated to continue using the beta router.

The Angular2-future way to implement this will be via the @Resolve decorator. Until then, the closest facsimile is CanActivate Component decorator, per Brandon Roberts. see https://github.com/angular/angular/issues/6611

Although beta 0 doesn't support providing resolved values to the Component, it's planned, and there is also a workaround described here: Using Resolve In Angular2 Routes

A beta 1 example can be found here: http://run.plnkr.co/BAqA98lphi4rQZAd/#/resolved . It uses a very similar workaround, but slightly more accurately uses the RouteData object rather than RouteParams.

@CanActivate((to) => {
    return new Promise((resolve) => {
        to.routeData.data.user = { name: 'John' }

Also, note that there is also an example workaround for accessing nested/parent route "resolved" values as well, and other features you expect if you've used 1.x UI-Router.

Note you'll also need to manually inject any services you need to accomplish this, since the Angular Injector hierarchy is not currently available in the CanActivate decorator. Simply importing an Injector will create a new injector instance, without access to the providers from bootstrap(), so you'll probably want to store an application-wide copy of the bootstrapped injector. Brandon's second Plunk link on this page is a good starting point: https://github.com/angular/angular/issues/4112

python: creating list from string

input = ['word1, 23, 12','word2, 10, 19','word3, 11, 15']
output = []
for item in input:
    items = item.split(',')
    output.append([items[0], int(items[1]), int(items[2])])

How to automatically generate getters and setters in Android Studio

Android Studio & Windows :

fn + alt + insert

Image of Menu

jQuery date/time picker

Take a look at the following JavaScript plugin.

Javascript Calendar with date and time

I've made it to be simple as possible. but it still in its early days. Let me know the feedback so I could improve it.

DateTime.ToString("MM/dd/yyyy HH:mm:ss.fff") resulted in something like "09/14/2013 07.20.31.371"

You can use InvariantCulture because your user must be in a culture that uses a dot instead of a colon:

DateTime.ToString("MM/dd/yyyy HH:mm:ss.fff", CultureInfo.InvariantCulture);

Gridview row editing - dynamic binding to a DropDownList

I am using a ListView instead of a GridView in 3.5. When the user wants to edit I have set the selected item of the dropdown to the exising value of that column for the record. I am able to access the dropdown in the ItemDataBound event. Here's the code:

protected void listViewABC_ItemDataBound(object sender, ListViewItemEventArgs e)
{
    // This stmt is used to execute the code only in case of edit 
    if (((ListView)(sender)).EditIndex != -1 && ((ListViewDataItem)(e.Item)).DisplayIndex == ((ListView)(sender)).EditIndex)
    {
        ((DropDownList)(e.Item.FindControl("ddlXType"))).SelectedValue = ((MyClass)((ListViewDataItem)e.Item).DataItem).XTypeId.ToString();
        ((DropDownList)(e.Item.FindControl("ddlIType"))).SelectedValue = ((MyClass)((ListViewDataItem)e.Item).DataItem).ITypeId.ToString();
    }
}

Vertical divider CSS

<div class="headerdivider"></div>

and

.headerdivider {
    border-left: 1px solid #38546d;
    background: #16222c;
    width: 1px;
    height: 80px;
    position: absolute;
    right: 250px;
    top: 10px;
}

Eclipse Build Path Nesting Errors

Try this:

From the libraries tab:

Eclipse -> right click on project name in sidebar -> configure build path -> Libraries

Remove your web app libraries:

click on "Web App Libraries" -> click "remove"

Add them back in:

click "Add Library" -> click to highlight "Web App Libraries" -> click "next" -> confirm your desired project is the selected option -> click "Finish"

Highlighting "Web App Libraries":

Highlighting "Web App Libraries"

Difference between "managed" and "unmanaged"

This is more general than .NET and Windows. Managed is an environment where you have automatic memory management, garbage collection, type safety, ... unmanaged is everything else. So for example .NET is a managed environment and C/C++ is unmanaged.

Using getResources() in non-activity class

here is my answer:

public class WigetControl {
private Resources res;

public WigetControl(Resources res) 
{
    this.res = res;
}

public void setButtonDisable(Button mButton)
{
    mButton.setBackgroundColor(res.getColor(R.color.loginbutton_unclickable));
    mButton.setEnabled(false);
}

}

and the call can be like this:

        WigetControl control = new WigetControl(getResources());
        control.setButtonDisable(btNext);

How to get string objects instead of Unicode from JSON?

here is a recursive encoder written in C: https://github.com/axiros/nested_encode

Performance overhead for "average" structures around 10% compared to json.loads.

python speed.py                                                                                            
  json loads            [0.16sec]: {u'a': [{u'b': [[1, 2, [u'\xd6ster..
  json loads + encoding [0.18sec]: {'a': [{'b': [[1, 2, ['\xc3\x96ster.
  time overhead in percent: 9%

using this teststructure:

import json, nested_encode, time

s = """
{
  "firstName": "Jos\\u0301",
  "lastName": "Smith",
  "isAlive": true,
  "age": 25,
  "address": {
    "streetAddress": "21 2nd Street",
    "city": "\\u00d6sterreich",
    "state": "NY",
    "postalCode": "10021-3100"
  },
  "phoneNumbers": [
    {
      "type": "home",
      "number": "212 555-1234"
    },
    {
      "type": "office",
      "number": "646 555-4567"
    }
  ],
  "children": [],
  "spouse": null,
  "a": [{"b": [[1, 2, ["\\u00d6sterreich"]]]}]
}
"""


t1 = time.time()
for i in xrange(10000):
    u = json.loads(s)
dt_json = time.time() - t1

t1 = time.time()
for i in xrange(10000):
    b = nested_encode.encode_nested(json.loads(s))
dt_json_enc = time.time() - t1

print "json loads            [%.2fsec]: %s..." % (dt_json, str(u)[:20])
print "json loads + encoding [%.2fsec]: %s..." % (dt_json_enc, str(b)[:20])

print "time overhead in percent: %i%%"  % (100 * (dt_json_enc - dt_json)/dt_json)

php_network_getaddresses: getaddrinfo failed: Name or service not known

In my case this error caused by wrong /etc/nsswitch.conf configuration on debian.

I've been replaced string

hosts:          files myhostname mdns4_minimal [NOTFOUND=return] dns

with

hosts:          files dns

and everything works right now.

Android: Getting "Manifest merger failed" error after updating to a new version of gradle

I solve that with putting this at the end of my app module build.gradle:

    configurations.all {
     resolutionStrategy.eachDependency { DependencyResolveDetails details ->
    def requested = details.requested
    if (requested.group == 'com.android.support') {
        if (!requested.name.startsWith("multidex")) {
            details.useVersion '26.0.0'
        }
    }
  }
}

How do you create a read-only user in PostgreSQL?

Reference taken from this blog:

Script to Create Read-Only user:

CREATE ROLE Read_Only_User WITH LOGIN PASSWORD 'Test1234' 
NOSUPERUSER INHERIT NOCREATEDB NOCREATEROLE NOREPLICATION VALID UNTIL 'infinity';

Assign permission to this read only user:

GRANT CONNECT ON DATABASE YourDatabaseName TO Read_Only_User;
GRANT USAGE ON SCHEMA public TO Read_Only_User;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO Read_Only_User;
GRANT SELECT ON ALL SEQUENCES IN SCHEMA public TO Read_Only_User;

Assign permissions to read all newly tables created in the future

ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO Read_Only_User;

How to monitor network calls made from iOS Simulator

A man-in-the-middle proxy, like suggested by other answers, is a good solution if you only want to see HTTP/HTTPS traffic. Burp Suite is pretty good. It may be a pain to configure though. I'm not sure how you would convince the simulator to talk to it. You might have to set the proxy on your local Mac to your instance of a proxy server in order for it to intercept, since the simulator will make use of your local Mac's environment.

The best solution for packet sniffing (though it only works for actual iOS devices, not the simulator) I've found is to use rvictl. This blog post has a nice writeup. Basically you do:

rvictl -s <iphone-uid-from-xcode-organizer>

Then you sniff the interface it creates with with Wireshark (or your favorite tool), and when you're done shut down the interface with:

rvictl -x <iphone-uid-from-xcode-organizer>

This is nice because if you want to packet sniff the simulator, you're having to wade through traffic to your local Mac as well, but rvictl creates a virtual interface that just shows you the traffic from the iOS device you've plugged into your USB port.

python date of the previous month

def prev_month(date=datetime.datetime.today()):
    if date.month == 1:
        return date.replace(month=12,year=date.year-1)
    else:
        try:
            return date.replace(month=date.month-1)
        except ValueError:
            return prev_month(date=date.replace(day=date.day-1))

Forward X11 failed: Network error: Connection refused

Do not log in as a root user, try another one with sudo permissions.

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

As it says, it is ambiguous. Your array comparison returns a boolean array. Methods any() and all() reduce values over the array (either logical_or or logical_and). Moreover, you probably don't want to check for equality. You should replace your condition with:

np.allclose(A.dot(eig_vec[:,col]), eig_val[col] * eig_vec[:,col])

Copy file from source directory to binary directory using CMake

The first of option you tried doesn't work for two reasons.

First, you forgot to close the parenthesis.

Second, the DESTINATION should be a directory, not a file name. Assuming that you closed the parenthesis, the file would end up in a folder called input.txt.

To make it work, just change it to

file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/input.txt
     DESTINATION ${CMAKE_CURRENT_BINARY_DIR})

allowing only alphabets in text box using java script

<html>
<head>
    <title>allwon only alphabets in textbox using JavaScript</title>
    <script language="Javascript" type="text/javascript">

        function onlyAlphabets(e, t) {
            try {
                if (window.event) {
                    var charCode = window.event.keyCode;
                }
                else if (e) {
                    var charCode = e.which;
                }
                else { return true; }
                if ((charCode > 64 && charCode < 91) || (charCode > 96 && charCode < 123))
                    return true;
                else
                    return false;
            }
            catch (err) {
                alert(err.Description);
            }
        }

    </script>
</head>
<body>
    <table align="center">
        <tr>
            <td>
                <input type="text" onkeypress="return onlyAlphabets(event,this);" />
            </td>
        </tr>
    </table>
</body>
</html>

Send multiple checkbox data to PHP via jQuery ajax()

var myCheckboxes = new Array();
$("input:checked").each(function() {
   data['myCheckboxes[]'].push($(this).val());
});

You are pushing checkboxes to wrong array data['myCheckboxes[]'] instead of myCheckboxes.push

Using Python's list index() method on a list of tuples or objects?

tuple_list = [("pineapple", 5), ("cherry", 7), ("kumquat", 3), ("plum", 11)]

def eachtuple(tupple, pos1, val):
    for e in tupple:
        if e == val:
            return True

for e in tuple_list:
    if eachtuple(e, 1, 7) is True:
        print tuple_list.index(e)

for e in tuple_list:
    if eachtuple(e, 0, "kumquat") is True:
        print tuple_list.index(e)

How to check java bit version on Linux?

Why don't you examine System.getProperty("os.arch") value in your code?

How to install Selenium WebDriver on Mac OS

First up you need to download Selenium jar files from http://www.seleniumhq.org/download/. Then you'd need an IDE, something like IntelliJ or Eclipse. Then you'll have to map your jar files to those IDEs. Then depending on which language/framework you choose, you'll have to download the relevant library files, for example, if you're using JUnit you'll have to download Junit 4.11 jar file. Finally don't forget to download the drivers for Chrome and Safari (firefox driver comes standard with selenium). Once done, you can start coding and testing your code with the browser of your choice.

Space between two rows in a table?

You can fill the <td/> elements with <div/> elements, and apply any margin to those divs that you like. For a visual space between the rows, you can use a repeating background image on the <tr/> element. (This was the solution I just used today, and it appears to work in both IE6 and FireFox 3, though I didn't test it any further.)

Also, if you're averse to modifying your server code to put <div/>s inside the <td/>s, you can use jQuery (or something similar) to dynamically wrap the <td/> contents in a <div/>, enabling you to apply the CSS as desired.

I can't understand why this JAXB IllegalAnnotationException is thrown

I was having the same issue

My Issue

Caused by: java.security.PrivilegedActionException: com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException: 2 counts of IllegalAnnotationExceptions

Two classes have the same XML type name "{urn:cpq_tns_Kat_getgroupsearch}Kat_getgroupsearch". Use @XmlType.name and @XmlType.namespace to assign different names to them.
this problem is related to the following location:
at katrequest.cpq_tns_kat_getgroupsearch.KatGetgroupsearch
at public javax.xml.bind.JAXBElement katrequest.cpq_tns_kat_getgroupsearch.ObjectFactory.createKatGetgroupsearch(katrequest.cpq_tns_kat_getgroupsearch.KatGetgroupsearch)
at katrequest.cpq_tns_kat_getgroupsearch.ObjectFactory
this problem is related to the following location:
at cpq_tns_kat_getgroupsearch.KatGetgroupsearch

Two classes have the same XML type name "{urn:cpq_tns_Kat_getgroupsearch}Kat_getgroupsearchResponse0". Use @XmlType.name and @XmlType.namespace to assign different names to them.
this problem is related to the following location:
at katrequest.cpq_tns_kat_getgroupsearch.KatGetgroupsearchResponse0
at public javax.xml.bind.JAXBElement katrequest.cpq_tns_kat_getgroupsearch.ObjectFactory.createKatGetgroupsearchResponse0(katrequest.cpq_tns_kat_getgroupsearch.KatGetgroupsearchResponse0)
at katrequest.cpq_tns_kat_getgroupsearch.ObjectFactory
this problem is related to the following location:
at cpq_tns_kat_getgroupsearch.KatGetgroupsearchResponse0

Changed made to solve it are below

I change the respective name to namespace

@XmlAccessorType(XmlAccessType.FIELD) @XmlType(**name** =
    "Kat_getgroupsearch", propOrder = {

    @XmlAccessorType(XmlAccessType.FIELD) @XmlType(namespace =
    "Kat_getgroupsearch", propOrder = {


@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(**name** = "Kat_getgroupsearchResponse0", propOrder = {

   @XmlAccessorType(XmlAccessType.FIELD)
   @XmlType(namespace = "Kat_getgroupsearchResponse0", propOrder = {

why?

As written in error log two classes have same name so we should use namespace because XML namespaces are used for providing uniquely named elements and attributes in an XML document.

Using PropertyInfo to find out the property type

Use PropertyInfo.PropertyType to get the type of the property.

public bool ValidateData(object data)
{
    foreach (PropertyInfo propertyInfo in data.GetType().GetProperties())
    {
        if (propertyInfo.PropertyType == typeof(string))
        {
            string value = propertyInfo.GetValue(data, null);

            if value is not OK
            {
                return false;
            }
        }
    }            

    return true;
}

How to add target="_blank" to JavaScript window.location?

_x000D_
_x000D_
    var linkGo = function(item) {_x000D_
      $(item).on('click', function() {_x000D_
        var _$this = $(this);_x000D_
        var _urlBlank = _$this.attr("data-link");_x000D_
        var _urlTemp = _$this.attr("data-url");_x000D_
        if (_urlBlank === "_blank") {_x000D_
          window.open(_urlTemp, '_blank');_x000D_
        } else {_x000D_
          // cross-origin_x000D_
          location.href = _urlTemp;_x000D_
        }_x000D_
      });_x000D_
    };_x000D_
_x000D_
    linkGo(".button__main[data-link]");
_x000D_
.button{cursor:pointer;}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
_x000D_
_x000D_
<span class="button button__main" data-link="" data-url="https://stackoverflow.com/">go stackoverflow</span>
_x000D_
_x000D_
_x000D_

event Action<> vs event EventHandler<>

The main difference will be that if you use Action<> your event will not follow the design pattern of virtually any other event in the system, which I would consider a drawback.

One upside with the dominating design pattern (apart from the power of sameness) is that you can extend the EventArgs object with new properties without altering the signature of the event. This would still be possible if you used Action<SomeClassWithProperties>, but I don't really see the point with not using the regular approach in that case.

Oracle: how to add minutes to a timestamp?

Be sure that Oracle understands that the starting time is PM, and to specify the HH24 format mask for the final output.

SELECT to_char((to_date('12:40 PM', 'HH:MI AM') + (1/24/60) * 30), 'HH24:MI') as time
  FROM dual

TIME
---------
13:10

Note: the 'AM' in the HH:MI is just the placeholder for the AM/PM meridian indicator. Could be also 'PM'

Make an image follow mouse pointer

Ok, here's a simple box that follows the cursor

Doing the rest is a simple case of remembering the last cursor position and applying a formula to get the box to move other than exactly where the cursor is. A timeout would also be handy if the box has a limited acceleration and must catch up to the cursor after it stops moving. Replacing the box with an image is simple CSS (which can replace most of the setup code for the box). I think the actual thinking code in the example is about 8 lines.

Select the right image (use a sprite) to orientate the rocket.

Yeah, annoying as hell. :-)

_x000D_
_x000D_
function getMouseCoords(e) {
  var e = e || window.event;
  document.getElementById('container').innerHTML = e.clientX + ', ' +
    e.clientY + '<br>' + e.screenX + ', ' + e.screenY;
}


var followCursor = (function() {
  var s = document.createElement('div');
  s.style.position = 'absolute';
  s.style.margin = '0';
  s.style.padding = '5px';
  s.style.border = '1px solid red';
  s.textContent = ""

  return {
    init: function() {
      document.body.appendChild(s);
    },

    run: function(e) {
      var e = e || window.event;
      s.style.left = (e.clientX - 5) + 'px';
      s.style.top = (e.clientY - 5) + 'px';
      getMouseCoords(e);
    }
  };
}());

window.onload = function() {
  followCursor.init();
  document.body.onmousemove = followCursor.run;
}
_x000D_
#container {
  width: 1000px;
  height: 1000px;
  border: 1px solid blue;
}
_x000D_
<div id="container"></div>
_x000D_
_x000D_
_x000D_

openssl s_client -cert: Proving a client certificate was sent to the server

In order to verify a client certificate is being sent to the server, you need to analyze the output from the combination of the -state and -debug flags.

First as a baseline, try running

$ openssl s_client -connect host:443 -state -debug

You'll get a ton of output, but the lines we are interested in look like this:

SSL_connect:SSLv3 read server done A
write to 0x211efb0 [0x21ced50] (12 bytes => 12 (0xC))
0000 - 16 03 01 00 07 0b 00 00-03                        .........
000c - <SPACES/NULS>
SSL_connect:SSLv3 write client certificate A

What's happening here:

  • The -state flag is responsible for displaying the end of the previous section:

    SSL_connect:SSLv3 read server done A  
    

    This is only important for helping you find your place in the output.

  • Then the -debug flag is showing the raw bytes being sent in the next step:

    write to 0x211efb0 [0x21ced50] (12 bytes => 12 (0xC))
    0000 - 16 03 01 00 07 0b 00 00-03                        .........
    000c - <SPACES/NULS>
    
  • Finally, the -state flag is once again reporting the result of the step that -debug just echoed:

    SSL_connect:SSLv3 write client certificate A
    

So in other words: s_client finished reading data sent from the server, and sent 12 bytes to the server as (what I assume is) a "no client certificate" message.


If you repeat the test, but this time include the -cert and -key flags like this:

$ openssl s_client -connect host:443 \
   -cert cert_and_key.pem \
   -key cert_and_key.pem  \
   -state -debug

your output between the "read server done" line and the "write client certificate" line will be much longer, representing the binary form of your client certificate:

SSL_connect:SSLv3 read server done A
write to 0x7bd970 [0x86d890] (1576 bytes => 1576 (0x628))
0000 - 16 03 01 06 23 0b 00 06-1f 00 06 1c 00 06 19 31   ....#..........1
(*SNIP*)
0620 - 95 ca 5e f4 2f 6c 43 11-                          ..^%/lC.
SSL_connect:SSLv3 write client certificate A

The 1576 bytes is an excellent indication on its own that the cert was transmitted, but on top of that, the right-hand column will show parts of the certificate that are human-readable: You should be able to recognize the CN and issuer strings of your cert in there.

Remove leading and trailing spaces?

Starting file:

     line 1
   line 2
line 3  
      line 4 

Code:

with open("filename.txt", "r") as f:
    lines = f.readlines()
    for line in lines:
        stripped = line.strip()
        print(stripped)

Output:

line 1
line 2
line 3
line 4

Getting the actual usedrange

Timings on Excel 2013 fairly slow machine with a big bad used range million rows:

26ms Cells.Find xlPrevious method (as above)

0.4ms Sheet.UsedRange (just call it)

0.14ms Counta binary search + 0.4ms Used Range to start search (12 CountA calls)

So the Find xlPrevious is quite slow if that is of concern.

The CountA binary search approach is to first do a Used Range. Then chop the range in half and see if there are any non-empty cells in the bottom half, and then halve again as needed. It is tricky to get right.

Invalid length parameter passed to the LEFT or SUBSTRING function

That would only happen if PostCode is missing a space. You could add conditionality such that all of PostCode is retrieved should a space not be found as follows

select SUBSTRING(PostCode, 1 ,
case when  CHARINDEX(' ', PostCode ) = 0 then LEN(PostCode) 
else CHARINDEX(' ', PostCode) -1 end)

JavaFX "Location is required." even though it is in the same package

I've seen this error a few times now. So often that I wrote a small project, called "Simple" with a Netbeans Maven FXML application template just to go back to as a kind of 'reference model' when things go askew. For testing, I use something like this:

    String sceneFile = "/fxml/main.fxml";
    Parent root = null;
    URL    url  = null;
    try
    {
        url  = getClass().getResource( sceneFile );
        root = FXMLLoader.load( url );
        System.out.println( "  fxmlResource = " + sceneFile );
    }
    catch ( Exception ex )
    {
        System.out.println( "Exception on FXMLLoader.load()" );
        System.out.println( "  * url: " + url );
        System.out.println( "  * " + ex );
        System.out.println( "    ----------------------------------------\n" );
        throw ex;
    }

When you run that snippet and the load fails, you should see a reason, or at least a message from the FXMLLoader. Since it's a test, I throw the exception. You don't want to continue.

Things to note. This is a maven project so the resources will be relative to the resources folder, hence:

  • "/fxml/main.fxml".
  • The leading slash is required.
  • The resource passed to the FXMLLoader is case-sensitive:

    // If you load "main.fxml" and your file is called: "Main.fxml"
    // You will will see the message ...
    
    java.lang.NullPointerException: Location is required.
    
  • If you get past that "location is required" issue, then you may have a problem in the FXML

    // Something like this: // javafx.fxml.LoadException: file:/D:/sandbox/javafx/app_examples/person/target/person-00.00.01-SNAPSHOT.jar!/fxml/tableWithDetails.fxml:13

Will mean that there's a problem on Line 13, in the file, per:

  • tableWithDetails.fxml :13

In the message. At this point you need to read the FXML and see if you can spot the problem. You could try some of the tips in the related question.

For this problem, my opinion is that the file name was proper case: "Main.fxml". When the file was moved the name was probably changed or the string retyped. Good luck.

Related:

BATCH file asks for file or folder

Well, for the task as asked by just me the perhaps best solution would be the following command according to the incomplete advice of Andy Morris:

xcopy "J:\My Name\FILES IN TRANSIT\JOHN20101126\Missing file\Shapes.atc" "C:\Documents and Settings\His name\Application Data\Autodesk\AutoCAD 2010\R18.0\enu\Support\" /Q /R /S /Y

This works for this simple file copying task because of

  • specifying just the destination directory instead of destination file and
  • ending destination directory with a backslash which is very important as otherwise XCOPY would even with /I prompt for file or directory on copying just a single file.

The other parameters not related to the question are:

  • /Q ... quiet
  • /Y ... yes (OS language independent) on overwrite existing file
  • /R ... overwrite also read-only, hidden and system file
  • /S ... from specified directory and all subdirectories.

Well, I don't know if /S is really needed here because it is unclear if just J:\My Name\FILES IN TRANSIT\JOHN20101126\Missing file\Shapes.atc should be copied or all Shapes.atc found anywhere in directory tree of J:\My Name\FILES IN TRANSIT\JOHN20101126\Missing file.

The explanation for the parameters can be read by opening a command prompt window and running from within this window xcopy /? to get output the help for XCOPY.


But none of the provided solutions worked for a file copying task on which a single file should be copied into same directory as source file, but with a different file name because of current date and time is inserted in file name before file extension.

The source file can have hidden or system attribute set which excludes the usage of COPY command.

The batch file for creating the time stamped file should work also on Windows XP which excludes ROBOCOPY because by default not available on Windows XP.

The batch file should work with any file including non typical files like .gitconfig or .htaccess which are files without a file extension starting with a point to hide them on *nix systems. Windows command processor interprets such files as files with no file name and having just a file extension because of the rule that everything after last point is the extension of the file and everything before last point is the file name.

For a complete task description and the final, fully commented solution see the post Create a backup copy of files in UltraEdit forum.

Patrick's, Tirtha R's, Interociter Operator's and CharlesB's solutions do not work because using /Y does not avoid the file or directory prompt if the destination file does not already exist.

Andy Morris' and grenix's solutions can't be used for the single file copying task as destination must be the name of destination file and not the name of destination directory. The destination directory is the same as the source directory, but name of destination file is different to name of source file.

DosMan's and Govert's solutions simply don't work for files starting with a point and not having a file extension.

For example the command

xcopy C:\Temp\.gitconfig C:\Temp\.gitconfig_2016-03-07_15-30-00* /C /H /K /Q /R /V /Y

results in following error message on execution:

English:  Could not expand second file name so as to match first.
German: Zweiter Dateiname konnte nicht so erweitert werden, dass er zum ersten passt.

And finally Denis Ivin's solution has the restriction that the operating system language dependent character for an automatic answering of the file OR directory prompt must be known.

So I thought about methods to get F for File on English Windows or D for Datei on German Windows or ? for ... on ... Windows automatically.

And it is indeed possible to determine the language dependent character for an automatic answering of the prompt.

A hack is used to get the language dependent letter from prompt text without really copying any file.

Command XCOPY is used to start copying the batch file itself to folder for temporary files with file extension being TMP for destination file. This results in a prompt by XCOPY if there is not already a file with that name in temporary files folder which is very unlikely.

The handler of device NUL is used as an input handler for XCOPY resulting in breaking the copying process after the prompt was output by XCOPY two times.

This output is processed in a FOR loop which is exited on first line starting with an opening parenthesis. This is the line on which second character defines the letter to use for specifying that destination is a file.

Here is a batch file using XCOPY with the code to determine the required letter for an automatic answering of the file or directory prompt to create a time stamped copy of a single file in same directory as the source file even if source file is a hidden or system file and even if the source file starts with a point and does not have a file extension.

@echo off
rem Batch file must be started or called with name of a single file.

if "%~1" == "" exit /B
for /F "delims=*?" %%I in ("#%~1#") do if not "%%I" == "#%~1#" exit /B
if not exist "%~1" exit /B
if exist "%~1\" exit /B
setlocal EnableDelayedExpansion

rem Determine the character needed for answering prompt of
rem XCOPY for destination being a file and not a directory.

del /F "%TEMP%\%~n0.tmp" 2>nul
for /F %%I in ('%SystemRoot%\System32\xcopy.exe "%~f0" "%TEMP%\%~n0.tmp" ^<nul') do (
    set "PromptAnswer=%%I"
    if "!PromptAnswer:~0,1!" == "(" (
        set "PromptAnswer=!PromptAnswer:~1,1!"
        goto CopyFile
    )
)
echo ERROR: Failed to determine letter for answering prompt of XCOPY.
exit /B

:CopyFile
rem This is a workaround for files starting with a point and having no
rem file extension like many hidden files on *nix copied to Windows.

if "%~n1" == "" (
    set "FileNameWithPath=%~dpx1"
    set "FileExtension="
) else (
    set "FileNameWithPath=%~dpn1"
    set "FileExtension=%~x1"
)

rem Get local date and time in region and language independent format YYYYMMDDHHmmss
rem and reformat the local date and time to format YYYY-MM-DD_HH-mm-ss.

for /F "tokens=2 delims==." %%I in ('%SystemRoot%\System32\wbem\wmic.exe OS get LocalDateTime /format:value') do set "LocalDateTime=%%I"
set "LocalDateTime=%LocalDateTime:~0,4%-%LocalDateTime:~4,2%-%LocalDateTime:~6,2%_%LocalDateTime:~8,2%-%LocalDateTime:~10,2%-%LocalDateTime:~12,2%"

rem Do the copy with showing what is copied and with printing success or
rem an error message if copying fails for example on sharing violation.

echo Copy "%~f1" to "%FileNameWithPath%_%LocalDateTime%%FileExtension%"

for /F %%I in ('echo %PromptAnswer% ^| %SystemRoot%\System32\xcopy.exe "%~f1" "%FileNameWithPath%_%LocalDateTime%%FileExtension%" /C /H /K /Q /R /V /Y') do set "FilesCopied=%%I"

if "%FilesCopied%" == "1" (
    echo Success
) else (
    echo ERROR: Copying failed, see error message above.
)

This batch code was tested on German Windows XP SP3 x86 and English Windows 7 SP1 x64.

See the post Create a backup copy of files in UltraEdit forum for a similar, fully commented batch file explaining all parts of the batch code.

For understanding the used commands and how they work, open a command prompt window, execute there the following commands, and read entirely all help pages displayed for each command very carefully.

  • del /?
  • echo /?
  • exit /?
  • for /?
  • goto /?
  • if /?
  • rem /?
  • set /?
  • setlocal /?
  • wmic OS get /?
  • xcopy /?

Further the Microsoft article about Using command redirection operators should be read, too.

Could not calculate build plan: Plugin org.apache.maven.plugins:maven-jar-plugin:2.3.2 or one of its dependencies could not be resolved

I have had this issue, and removing the .m2/repository/ has not solved it in my case. Seems that eclipse is unable to download the maven-plugin or dependency needed. Therefore you need to install it yourself.

I have finally solved it downloading both jar and pom files from the Maven Repository and installing it using the command (better than copying to the folder directly): mvn install:install-file -Dfile=<path-to-file> -DpomFile=<path-to-pomfile> (In my case: mvn install:install-file -Dfile=maven-war-plugin-2.2.pom -DpomFile=maven-war-plugin-2.2.pom)

Do sessions really violate RESTfulness?

No, using sessions does not necessarily violate RESTfulness. If you adhere to the REST precepts and constraints, then using sessions - to maintain state - will simply be superfluous. After all, RESTfulness requires that the server not maintain state.

Calling C++ class methods via a function pointer

A function pointer to a class member is a problem that is really suited to using boost::function. Small example:

#include <boost/function.hpp>
#include <iostream>

class Dog 
{
public:
   Dog (int i) : tmp(i) {}
   void bark ()
   {
      std::cout << "woof: " << tmp << std::endl;
   }
private:
   int tmp;
};



int main()
{
   Dog* pDog1 = new Dog (1);
   Dog* pDog2 = new Dog (2);

   //BarkFunction pBark = &Dog::bark;
   boost::function<void (Dog*)> f1 = &Dog::bark;

   f1(pDog1);
   f1(pDog2);
}

Git Push error: refusing to update checked out branch

Summary

You cannot push to the one checked out branch of a repository because it would mess with the user of that repository in a way that will most probably end with loss of data and history. But you can push to any other branch of the same repository.

As bare repositories never have any branch checked out, you can always push to any branch of a bare repository.

Autopsy of the problem

When a branch is checked out, committing will add a new commit with the current branch's head as its parent and move the branch's head to be that new commit.

So

A ? B
    ?
[HEAD,branch1]

becomes

A ? B ? C
        ?
    [HEAD,branch1]

But if someone could push to that branch inbetween, the user would get itself in what git calls detached head mode:

A ? B ? X
    ?   ?
[HEAD] [branch1]

Now the user is not in branch1 anymore, without having explicitly asked to check out another branch. Worse, the user is now outside any branch, and any new commit will just be dangling:

      [HEAD]
        ?
        C
      ?
A ? B ? X
        ?
       [branch1]

Hypothetically, if at this point, the user checks out another branch, then this dangling commit becomes fair game for Git's garbage collector.

Format datetime in asp.net mvc 4

Thanks Darin, For me, to be able to post to the create method, It only worked after I modified the BindModel code to :

public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
    var displayFormat = bindingContext.ModelMetadata.DisplayFormatString;
    var value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);

    if (!string.IsNullOrEmpty(displayFormat) && value != null)
    {
        DateTime date;
        displayFormat = displayFormat.Replace("{0:", string.Empty).Replace("}", string.Empty);
        // use the format specified in the DisplayFormat attribute to parse the date
         if (DateTime.TryParse(value.AttemptedValue, CultureInfo.GetCultureInfo("en-GB"), DateTimeStyles.None, out date))
        {
            return date;
        }
        else
        {
            bindingContext.ModelState.AddModelError(
                bindingContext.ModelName,
                string.Format("{0} is an invalid date format", value.AttemptedValue)
            );
        }
    }

    return base.BindModel(controllerContext, bindingContext);
}

Hope this could help someone else...

[] and {} vs list() and dict(), which is better?

The dict literal might be a tiny bit faster as its bytecode is shorter:

In [1]: import dis
In [2]: a = lambda: {}
In [3]: b = lambda: dict()

In [4]: dis.dis(a)
  1           0 BUILD_MAP                0
              3 RETURN_VALUE

In [5]: dis.dis(b)
  1           0 LOAD_GLOBAL              0 (dict)
              3 CALL_FUNCTION            0
              6 RETURN_VALUE

Same applies to the list vs []

Adding quotes to a string in VBScript

You can do like:

a="""xyz"""  
g="abcd " & a  

Or:

a=chr(34) & "xyz" & chr(34)
g="abcd " & a  

Python Prime number checker

This is a slight variation in that it keeps track of the factors.

def prime(a):
    list=[]
    x=2
    b=True

    while x<a:
        if a%x==0:
            b=False
            list.append(x)
        x+=1

    if b==False:
        print "Not Prime"
        print list
    else:
        print "Prime"

How to create nonexistent subdirectories recursively using Bash?

While existing answers definitely solve the purpose, if your'e looking to replicate nested directory structure under two different subdirectories, then you can do this

mkdir -p {main,test}/{resources,scala/com/company}

It will create following directory structure under the directory from where it is invoked

+-- main
¦   +-- resources
¦   +-- scala
¦       +-- com
¦           +-- company
+-- test
    +-- resources
    +-- scala
        +-- com
            +-- company

The example was taken from this link for creating SBT directory structure

What is the convention for word separator in Java package names?

Underscores look ugly in package names. For what is worth, in case of names compound of three or more words I use initials (for example: com.company.app.ingresoegresofijo (ingreso/egreso fijo) -> com.company.app.iefijo) and then document the package purpose in package-info.java.

What's the difference between a POST and a PUT HTTP REQUEST?

Actually there's no difference other than their title. There's actually a basic difference between GET and the others. With a "GET"-Request method, you send the data in the url-address-line, which are separated first by a question-mark, and then with a & sign.

But with a "POST"-request method, you can't pass data through the url, but you have to pass the data as an object in the so called "body" of the request. On the server side, you have then to read out the body of the received content in order to get the sent data. But there's on the other side no possibility to send content in the body, when you send a "GET"-Request.

The claim, that "GET" is only for getting data and "POST" is for posting data, is absolutely wrong. Noone can prevent you from creating new content, deleting existing content, editing existing content or do whatever in the backend, based on the data, that is sent by the "GET" request or by the "POST" request. And nobody can prevent you to code the backend in a way, that with a "POST"-Request, the client asks for some data.

With a request, no matter which method you use, you call a URL and send or don't send some data to specify, which information you want to pass to the server to deal with your request, and then the client gets an answer from the server. The data can contain whatever you want to send, the backend is allowed to do whatever it wants with the data and the response can contain any information, that you want to put in there.

There are only these two BASIC METHODS. GET and POST. But it's their structure, which makes them different and not what you code in the backend. In the backend you can code whatever you want to, with the received data. But with the "POST"-request you have to send/retrieve the data in the body and not in the url-addressline, and with a "GET" request, you have to send/retrieve data in the url-addressline and not in the body. That's all.

All the other methods, like "PUT", "DELETE" and so on, they have the same structure as "POST".

The POST Method is mainly used, if you want to hide the content somewhat, because whatever you write in the url-addressline, this will be saved in the cache and a GET-Method is the same as writing a url-addressline with data. So if you want to send sensitive data, which is not always necessarily username and password, but for example some ids or hashes, which you don't want to be shown in the url-address-line, then you should use the POST method.

Also the URL-Addressline's length is limited to 1024 symbols, whereas the "POST"-Method is not restricted. So if you have a bigger amount of data, you might not be able to send it with a GET-Request, but you'll need to use the POST-Request. So this is also another plus point for the POST-request.

But dealing with the GET-request is way easier, when you don't have complicated text to send. Otherwise, and this is another plus point for the POST method, is, that with the GET-method you need to url-encode the text, in order to be able to send some symbols within the text or even spaces. But with a POST method you have no restrictions and your content doesn't need to be changed or manipulated in any way.

How do you perform address validation?

As seen on reddit:

$address = urlencode('1600 Pennsylvania Avenue, Washington, DC');
$json = json_decode(file_get_contents("http://where.yahooapis.com/geocode?q=$address&flags=J"));
print_r($json);

change array size

This worked well for me to create a dynamic array from a class array.

var s = 0;
var songWriters = new SongWriterDetails[1];
foreach (var contributor in Contributors)
{
    Array.Resize(ref songWriters, s++);
    songWriters[s] = new SongWriterDetails();
    songWriters[s].DisplayName = contributor.Name;
    songWriters[s].PartyId = contributor.Id;
    s++;
}

How to identify a strong vs weak relationship on ERD?

  1. Weak (Non-Identifying) Relationship

    • Entity is existence-independent of other enties

    • PK of Child doesn’t contain PK component of Parent Entity

  2. Strong (Identifying) Relationship

    • Child entity is existence-dependent on parent

    • PK of Child Entity contains PK component of Parent Entity

    • Usually occurs utilizing a composite key for primary key, which means one of this composite key components must be the primary key of the parent entity.

How to insert pandas dataframe via mysqldb into database?

You can do it by using pymysql:

For example, let's suppose you have a MySQL database with the next user, password, host and port and you want to write in the database 'data_2', if it is already there or not.

import pymysql
user = 'root'
passw = 'my-secret-pw-for-mysql-12ud'
host =  '172.17.0.2'
port = 3306
database = 'data_2'

If you already have the database created:

conn = pymysql.connect(host=host,
                       port=port,
                       user=user, 
                       passwd=passw,  
                       db=database,
                       charset='utf8')

data.to_sql(name=database, con=conn, if_exists = 'replace', index=False, flavor = 'mysql')

If you do NOT have the database created, also valid when the database is already there:

conn = pymysql.connect(host=host, port=port, user=user, passwd=passw)

conn.cursor().execute("CREATE DATABASE IF NOT EXISTS {0} ".format(database))
conn = pymysql.connect(host=host,
                       port=port,
                       user=user, 
                       passwd=passw,  
                       db=database,
                       charset='utf8')

data.to_sql(name=database, con=conn, if_exists = 'replace', index=False, flavor = 'mysql')

Similar threads:

  1. Writing to MySQL database with pandas using SQLAlchemy, to_sql
  2. Writing a Pandas Dataframe to MySQL

Lua string to int

Use the tonumber function. As in a = tonumber("10").

View RDD contents in Python Spark?

Try this:

data = f.flatMap(lambda x: x.split(' '))
map = data.map(lambda x: (x, 1))
mapreduce = map.reduceByKey(lambda x,y: x+y)
result = mapreduce.collect()

Please note that when you run collect(), the RDD - which is a distributed data set is aggregated at the driver node and is essentially converted to a list. So obviously, it won't be a good idea to collect() a 2T data set. If all you need is a couple of samples from your RDD, use take(10).

How to draw text using only OpenGL methods?

I think that the best solution for drawing text in OpenGL is texture fonts, I work with them for a long time. They are flexible, fast and nice looking (with some rear exceptions). I use special program for converting font files (.ttf for example) to texture, which is saved to file of some internal "font" format (I've developed format and program based on http://content.gpwiki.org/index.php/OpenGL:Tutorials:Font_System though my version went rather far from the original supporting Unicode and so on). When starting the main app, fonts are loaded from this "internal" format. Look link above for more information.

With such approach the main app doesn't use any special libraries like FreeType, which is undesirable for me also. Text is being drawn using standard OpenGL functions.

Iterating over a numpy array

I see that no good desciption for using numpy.nditer() is here. So, I am gonna go with one. According to NumPy v1.21 dev0 manual, The iterator object nditer, introduced in NumPy 1.6, provides many flexible ways to visit all the elements of one or more arrays in a systematic fashion.

I have to calculate mean_squared_error and I have already calculate y_predicted and I have y_actual from the boston dataset, available with sklearn.

def cal_mse(y_actual, y_predicted):
    """ this function will return mean squared error
       args:
           y_actual (ndarray): np array containing target variable
           y_predicted (ndarray): np array containing predictions from DecisionTreeRegressor
       returns:
           mse (integer)
    """
    sq_error = 0
    for i in np.nditer(np.arange(y_pred.shape[0])):
        sq_error += (y_actual[i] - y_predicted[i])**2
    mse = 1/y_actual.shape[0] * sq_error
    
    return mse

Hope this helps :). for further explaination visit

Firebase TIMESTAMP to date and Time

Firebase.ServerValue.TIMESTAMP is the same as new Date().getTime().

Convert it:

var timestamp = '1452488445471';
var myDate = new Date(timestamp).getTime();

Assigning a variable NaN in python without numpy

Yes -- use math.nan.

>>> from math import nan
>>> print(nan)
nan
>>> print(nan + 2)
nan
>>> nan == nan
False
>>> import math
>>> math.isnan(nan)
True

Before Python 3.5, one could use float("nan") (case insensitive).

Note that checking to see if two things that are NaN are equal to one another will always return false. This is in part because two things that are "not a number" cannot (strictly speaking) be said to be equal to one another -- see What is the rationale for all comparisons returning false for IEEE754 NaN values? for more details and information.

Instead, use math.isnan(...) if you need to determine if a value is NaN or not.

Furthermore, the exact semantics of the == operation on NaN value may cause subtle issues when trying to store NaN inside container types such as list or dict (or when using custom container types). See Checking for NaN presence in a container for more details.


You can also construct NaN numbers using Python's decimal module:

>>> from decimal import Decimal
>>> b = Decimal('nan')
>>> print(b)
NaN
>>> print(repr(b))
Decimal('NaN')
>>>
>>> Decimal(float('nan'))
Decimal('NaN')
>>> 
>>> import math
>>> math.isnan(b)
True

math.isnan(...) will also work with Decimal objects.


However, you cannot construct NaN numbers in Python's fractions module:

>>> from fractions import Fraction
>>> Fraction('nan')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python35\lib\fractions.py", line 146, in __new__
    numerator)
ValueError: Invalid literal for Fraction: 'nan'
>>>
>>> Fraction(float('nan'))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python35\lib\fractions.py", line 130, in __new__
    value = Fraction.from_float(numerator)
  File "C:\Python35\lib\fractions.py", line 214, in from_float
    raise ValueError("Cannot convert %r to %s." % (f, cls.__name__))
ValueError: Cannot convert nan to Fraction.

Incidentally, you can also do float('Inf'), Decimal('Inf'), or math.inf (3.5+) to assign infinite numbers. (And also see math.isinf(...))

However doing Fraction('Inf') or Fraction(float('inf')) isn't permitted and will throw an exception, just like NaN.

If you want a quick and easy way to check if a number is neither NaN nor infinite, you can use math.isfinite(...) as of Python 3.2+.


If you want to do similar checks with complex numbers, the cmath module contains a similar set of functions and constants as the math module:

How to save a spark DataFrame as csv on disk?

Writing dataframe to disk as csv is similar read from csv. If you want your result as one file, you can use coalesce.

df.coalesce(1)
      .write
      .option("header","true")
      .option("sep",",")
      .mode("overwrite")
      .csv("output/path")

If your result is an array you should use language specific solution, not spark dataframe api. Because all these kind of results return driver machine.

Get-WmiObject : The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

I found this blog post which suggested adding a firewall exception for "Remote Administration", and that worked for us on our Windows Server 2008 Enterprise systems.

http://mikefrobbins.com/2012/03/08/get-wmiobject-the-rpc-server-is-unavailable-exception-from-hresult-0x800706ba/

docker command not found even though installed with apt-get

IMPORTANT - on ubuntu package docker is something entirely different ( avoid it ) :

issue following to view what if any packages you have mentioning docker

dpkg -l|grep docker

if only match is following then you do NOT have docker installed below is an unrelated package

docker - System tray for KDE3/GNOME2 docklet applications

if you see something similar to following then you have docker installed

 dpkg -l|grep docker

ii  docker-ce                                  5:19.03.13~3-0~ubuntu-focal         amd64        Docker: the open-source application container engine
ii  docker-ce-cli                              5:19.03.13~3-0~ubuntu-focal         amd64        Docker CLI: the open-source application container engine

NOTE - ubuntu package docker.io is not getting updates ( obsolete do NOT use )


Instead do this : install the latest version of docker on linux by executing the following:

  sudo curl -sSL https://get.docker.com/ | sh
# sudo curl -sSL https://test.docker.com | sh  # get dev pipeline version
  

here is a typical output ( ubuntu 16.04 )

apparmor is enabled in the kernel and apparmor utils were already installed
+ sudo -E sh -c apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
Executing: /tmp/tmp.rAAGu0P85R/gpg.1.sh --keyserver
hkp://ha.pool.sks-keyservers.net:80
--recv-keys
58118E89F3A912897C070ADBF76221572C52609D
gpg: requesting key 2C52609D from hkp server ha.pool.sks-keyservers.net
gpg: key 2C52609D: "Docker Release Tool (releasedocker) <[email protected]>" 1 new signature
gpg: Total number processed: 1
gpg:         new signatures: 1
+ break
+ sudo -E sh -c apt-key adv -k 58118E89F3A912897C070ADBF76221572C52609D >/dev/null
+ sudo -E sh -c mkdir -p /etc/apt/sources.list.d
+ dpkg --print-architecture
+ sudo -E sh -c echo deb [arch=amd64] https://apt.dockerproject.org/repo ubuntu-xenial main > /etc/apt/sources.list.d/docker.list
+ sudo -E sh -c sleep 3; apt-get update; apt-get install -y -q docker-engine
Hit:1 http://repo.steampowered.com/steam precise InRelease
Hit:2 http://download.virtualbox.org/virtualbox/debian xenial InRelease                                                           
Ign:3 http://dl.google.com/linux/chrome/deb stable InRelease                                                                      
Hit:4 http://dl.google.com/linux/chrome/deb stable Release                                                                        
Hit:5 http://archive.canonical.com/ubuntu xenial InRelease                                                                        
Hit:6 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial InRelease                                                     
Hit:7 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial-updates InRelease                                             
Hit:8 http://ppa.launchpad.net/me-davidsansome/clementine/ubuntu xenial InRelease                                                 
Ign:9 http://repo.mongodb.org/apt/debian wheezy/mongodb-org/3.2 InRelease                                                         
Hit:10 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial-backports InRelease                                          
Hit:11 http://repo.mongodb.org/apt/debian wheezy/mongodb-org/3.2 Release                                                          
Hit:12 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial-security InRelease                                           
Hit:14 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease                                                                 
Ign:15 http://linux.dropbox.com/ubuntu wily InRelease                                                                             
Ign:16 http://repo.vivaldi.com/stable/deb stable InRelease                                                                        
Hit:17 http://repo.vivaldi.com/stable/deb stable Release                                                                          
Get:18 http://linux.dropbox.com/ubuntu wily Release [6,596 B]            
Get:19 https://apt.dockerproject.org/repo ubuntu-xenial InRelease [20.6 kB]    
Ign:20 http://packages.amplify.nginx.com/ubuntu xenial InRelease                      
Hit:22 http://packages.amplify.nginx.com/ubuntu xenial Release
Hit:23 https://deb.opera.com/opera-beta stable InRelease
Hit:26 https://deb.opera.com/opera-developer stable InRelease
Get:28 https://apt.dockerproject.org/repo ubuntu-xenial/main amd64 Packages [1,719 B]
Hit:29 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease
Fetched 28.9 kB in 1s (17.2 kB/s)
Reading package lists... Done
W: http://repo.mongodb.org/apt/debian/dists/wheezy/mongodb-org/3.2/Release.gpg: Signature by key 42F3E95A2C4F08279C4960ADD68FA50FEA312927 uses weak digest algorithm (SHA1)
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  aufs-tools cgroupfs-mount
The following NEW packages will be installed:
  aufs-tools cgroupfs-mount docker-engine
0 upgraded, 3 newly installed, 0 to remove and 17 not upgraded.
Need to get 14.6 MB of archives.
After this operation, 73.7 MB of additional disk space will be used.
Get:1 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial/universe amd64 aufs-tools amd64 1:3.2+20130722-1.1ubuntu1 [92.9 kB]
Get:2 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial/universe amd64 cgroupfs-mount all 1.2 [4,970 B]
Get:3 https://apt.dockerproject.org/repo ubuntu-xenial/main amd64 docker-engine amd64 1.11.2-0~xenial [14.5 MB]
Fetched 14.6 MB in 7s (2,047 kB/s)
Selecting previously unselected package aufs-tools.
(Reading database ... 427978 files and directories currently installed.)
Preparing to unpack .../aufs-tools_1%3a3.2+20130722-1.1ubuntu1_amd64.deb ...
Unpacking aufs-tools (1:3.2+20130722-1.1ubuntu1) ...
Selecting previously unselected package cgroupfs-mount.
Preparing to unpack .../cgroupfs-mount_1.2_all.deb ...
Unpacking cgroupfs-mount (1.2) ...
Selecting previously unselected package docker-engine.
Preparing to unpack .../docker-engine_1.11.2-0~xenial_amd64.deb ...
Unpacking docker-engine (1.11.2-0~xenial) ...
Processing triggers for libc-bin (2.23-0ubuntu3) ...
Processing triggers for man-db (2.7.5-1) ...
Processing triggers for ureadahead (0.100.0-19) ...
Processing triggers for systemd (229-4ubuntu6) ...
Setting up aufs-tools (1:3.2+20130722-1.1ubuntu1) ...
Setting up cgroupfs-mount (1.2) ...
Setting up docker-engine (1.11.2-0~xenial) ...
Processing triggers for libc-bin (2.23-0ubuntu3) ...
Processing triggers for systemd (229-4ubuntu6) ...
Processing triggers for ureadahead (0.100.0-19) ...
+ sudo -E sh -c docker version
Client:
 Version:      1.11.2
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   b9f10c9
 Built:        Wed Jun  1 22:00:43 2016
 OS/Arch:      linux/amd64

Server:
 Version:      1.11.2
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   b9f10c9
 Built:        Wed Jun  1 22:00:43 2016
 OS/Arch:      linux/amd64

If you would like to use Docker as a non-root user, you should now consider
adding your user to the "docker" group with something like:

  sudo usermod -aG docker stens

Remember that you will have to log out and back in for this to take effect!

Here is the underlying detailed install instructions which as you can see comes bundled into above technique ... Above one liner gives you same as :

https://docs.docker.com/engine/installation/linux/ubuntulinux/

Once installed you can see what docker packages were installed by issuing

dpkg -l|grep docker
ii  docker-ce                                  5:19.03.13~3-0~ubuntu-focal         amd64        Docker: the open-source application container engine
ii  docker-ce-cli                              5:19.03.13~3-0~ubuntu-focal         amd64        Docker CLI: the open-source application container engine

now Docker updates will get installed going forward when you issue

sudo apt-get update
sudo apt-get upgrade

take a look at

 ls -latr /etc/apt/sources.list.d/*docker*
-rw-r--r-- 1 root root 202 Jun 23 10:01 /etc/apt/sources.list.d/docker.list.save
-rw-r--r-- 1 root root  71 Jul  4 11:32 /etc/apt/sources.list.d/docker.list


cat /etc/apt/sources.list.d/docker.list

deb [arch=amd64] https://apt.dockerproject.org/repo ubuntu-xenial main

or more generally

cd /etc/apt
grep -r docker *
sources.list.d/docker.list:deb [arch=amd64] https://download.docker.com/linux/ubuntu focal test

How to Delete a directory from Hadoop cluster which is having comma(,) in its name?

Here you can find all hadoop shell commands:

deleting: rmr Usage: hadoop fs -rmr URI [URI …]

Recursive version of delete.

Example:

hadoop fs -rmr /user/hadoop/dir
hadoop fs -rmr hdfs://nn.example.com/user/hadoop/dir

Exit Code:

Returns 0 on success and -1 on error.

How can I group by date time column without taking time into consideration

CAST datetime field to date

select  CAST(datetime_field as DATE), count(*) as count from table group by CAST(datetime_field as DATE);

Refresh Page and Keep Scroll Position

This might be useful for refreshing also. But if you want to keep track of position on the page before you click on a same position.. The following code will help.

Also added a data-confirm for prompting the user if they really want to do that..

Note: I'm using jQuery and js-cookie.js to store cookie info.

$(document).ready(function() {
    // make all links with data-confirm prompt the user first.
    $('[data-confirm]').on("click", function (e) {
        e.preventDefault();
        var msg = $(this).data("confirm");
        if(confirm(msg)==true) {
            var url = this.href;
            if(url.length>0) window.location = url;
            return true;
        }
        return false;
    });

    // on certain links save the scroll postion.
    $('.saveScrollPostion').on("click", function (e) {
        e.preventDefault();
        var currentYOffset = window.pageYOffset;  // save current page postion.
        Cookies.set('jumpToScrollPostion', currentYOffset);
        if(!$(this).attr("data-confirm")) {  // if there is no data-confirm on this link then trigger the click. else we have issues.
            var url = this.href;
            window.location = url;
            //$(this).trigger('click');  // continue with click event.
        }
    });

    // check if we should jump to postion.
    if(Cookies.get('jumpToScrollPostion') !== "undefined") {
        var jumpTo = Cookies.get('jumpToScrollPostion');
        window.scrollTo(0, jumpTo);
        Cookies.remove('jumpToScrollPostion');  // and delete cookie so we don't jump again.
    }
});

A example of using it like this.

<a href='gotopage.html' class='saveScrollPostion' data-confirm='Are you sure?'>Goto what the heck</a>

Passing variables in remote ssh command

If you use

ssh [email protected] "~/tools/run_pvt.pl $BUILD_NUMBER"

instead of

ssh [email protected] '~/tools/run_pvt.pl $BUILD_NUMBER'

your shell will interpolate the $BUILD_NUMBER before sending the command string to the remote host.

Fit cell width to content

There are many ways to do this!

correct me if I'm wrong but the question is looking for this kind of result.

<table style="white-space:nowrap;width:100%;">
<tr>
<td class="block" style="width:50%">this should stretch</td>
<td class="block" style="width:50%">this should stretch</td>
<td class="block" style="width:auto">this should be the content width</td>
</tr>
</table>

The first 2 fields will "share" the remaining page (NOTE: if you add more text to either 50% fields it will take more space), and the last field will dominate the table constantly.

If you are happy to let text wrap you can move white-space:nowrap; to the style of the 3rd field
will be the only way to start a new line in that field.

alternatively, you can set a length on the last field ie. width:150px, and leave percentage's on the first 2 fields.

Hope this helps!

Transposing a 1D NumPy array

I am just consolidating the above post, hope it will help others to save some time:

The below array has (2, )dimension, it's a 1-D array,

b_new = np.array([2j, 3j])  

There are two ways to transpose a 1-D array:


slice it with "np.newaxis" or none.!

print(b_new[np.newaxis].T.shape)
print(b_new[None].T.shape)

other way of writing, the above without T operation.!

print(b_new[:, np.newaxis].shape)
print(b_new[:, None].shape)

Wrapping [ ] or using np.matrix, means adding a new dimension.!

print(np.array([b_new]).T.shape)
print(np.matrix(b_new).T.shape)

git with IntelliJ IDEA: Could not read from remote repository

Nothing helped me. Then I saw that the name of the project on the computer is different from the name on the git repository.

So I solved the problem.

What data type to use in MySQL to store images?

What you need, according to your comments, is a 'BLOB' (Binary Large OBject) for both image and resume.

github changes not staged for commit

in my case, I needed a

 git add files
 git commit -am 'what I changed'
 git push

the 'a' on the commit was needed.

Why is it OK to return a 'vector' from a function?

Pre C++11:

The function will not return the local variable, but rather a copy of it. Your compiler might however perform an optimization where no actual copy action is made.

See this question & answer for further details.

C++11:

The function will move the value. See this answer for further details.

"psql: could not connect to server: Connection refused" Error when connecting to remote database

The following helped me on macos Mojave:

$sudo mv /usr/local/var/postgres /usr/local/var/postgres.save
$brew uninstall postgres
$brew install postgres

What is a "static" function in C?

A static function is one that can be called on the class itself, as opposed to an instance of the class.

For example a non-static would be:

Person* tom = new Person();
tom->setName("Tom");

This method works on an instance of the class, not the class itself. However you can have a static method that can work without having an instance. This is sometimes used in the Factory pattern:

Person* tom = Person::createNewPerson();

How to run a method every X seconds

Use Timer for every second...

new Timer().scheduleAtFixedRate(new TimerTask() {
    @Override
    public void run() {
        //your method
    }
}, 0, 1000);//put here time 1000 milliseconds=1 second

Conversion of a varchar data type to a datetime data type resulted in an out-of-range value in SQL query

some problem, but I find the solution, this is :


2 February Feb 28 (29 in leap years)

this is my code

 public string GetCountArchiveByMonth(int iii)
        {
// iii: is number of months, use any number other than (**2**)

            con.Open();

            SqlCommand cmd10 = con.CreateCommand();
            cmd10.CommandType = CommandType.Text;
            cmd10.CommandText = "select count(id_post) from posts where dateadded between CONVERT(VARCHAR, @start, 103) and CONVERT(VARCHAR, @end, 103)";
            cmd10.Parameters.AddWithValue("@start", "" + iii + "/01/2019");
            cmd10.Parameters.AddWithValue("@end", "" + iii + "/30/2019");
            string result = cmd10.ExecuteScalar().ToString();

            con.Close();

            return result;
        }

now for test

 lbl1.Text = GetCountArchiveByMonth(**7**).ToString();  // here use any number other than (**2**)

**

because of check **February** is maxed 28 days,

**

Failed to decode downloaded font

For me, the mistake was forgetting to put FTP into binary mode before uploading the font files.

Edit

You can test for this by uploading other types of binary data like images. If they also fail to display, then this may be your issue.

HttpListener Access Denied

Unfortunately, for some reasons probably linked with HTTPS and certificates, the native .NET HttpListener requires admin privileges, and even for HTTP only protocol...

The good point

It is interesting to note that HTTP protocol is on top of TCP protocol, but launching a C# TCP listener doesn't require any admin privileges to run. In other words, it is conceptually possible to implement an HTTP server which do not requires admin privileges.

Alternative

Below, an example of project which doesn't require admin privileges: https://github.com/EmilianoElMariachi/ElMariachi.Http.Server

How to configure ChromeDriver to initiate Chrome browser in Headless mode through Selenium?

It should look like this:

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.add_argument('--headless')
options.add_argument('--disable-gpu')  # Last I checked this was necessary.
driver = webdriver.Chrome(CHROMEDRIVER_PATH, chrome_options=options)

This works for me using Python 3.6, I'm sure it'll work for 2.7 too.

Update 2018-10-26: These days you can just do this:

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.headless = True
driver = webdriver.Chrome(CHROMEDRIVER_PATH, chrome_options=options)

Ring Buffer in Java

A very interesting project is disruptor. It has a ringbuffer and is used from what I know in financial applications.

See here: code of ringbuffer

I checked both Guava's EvictingQueue and ArrayDeque.

ArrayDeque does not limit growth if it's full it will double size and hence is not precisely acting like a ringbuffer.

EvictingQueue does what it promises but internally uses a Deque to store things and just bounds memory.

Hence, if you care about memory being bounded ArrayDeque is not fullfilling your promise. If you care about object count EvictingQueue uses internal composition (bigger object size).

A simple and memory efficient one can be stolen from jmonkeyengine. verbatim copy

import java.util.Iterator;
import java.util.NoSuchElementException;

public class RingBuffer<T> implements Iterable<T> {

  private T[] buffer;          // queue elements
  private int count = 0;          // number of elements on queue
  private int indexOut = 0;       // index of first element of queue
  private int indexIn = 0;       // index of next available slot

  // cast needed since no generic array creation in Java
  public RingBuffer(int capacity) {
    buffer = (T[]) new Object[capacity];
  }

  public boolean isEmpty() {
    return count == 0;
  }

  public int size() {
    return count;
  }

  public void push(T item) {
    if (count == buffer.length) {
        throw new RuntimeException("Ring buffer overflow");
    }
    buffer[indexIn] = item;
    indexIn = (indexIn + 1) % buffer.length;     // wrap-around
    count++;
  }

  public T pop() {
    if (isEmpty()) {
        throw new RuntimeException("Ring buffer underflow");
    }
    T item = buffer[indexOut];
    buffer[indexOut] = null;                  // to help with garbage collection
    count--;
    indexOut = (indexOut + 1) % buffer.length; // wrap-around
    return item;
  }

  public Iterator<T> iterator() {
    return new RingBufferIterator();
  }

  // an iterator, doesn't implement remove() since it's optional
  private class RingBufferIterator implements Iterator<T> {

    private int i = 0;

    public boolean hasNext() {
        return i < count;
    }

    public void remove() {
        throw new UnsupportedOperationException();
    }

    public T next() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }
        return buffer[i++];
    }
  }
}

Regular expression for not allowing spaces in the input field

This one will only match the input field or string if there are no spaces. If there are any spaces, it will not match at all.

/^([A-z0-9!@#$%^&*().,<>{}[\]<>?_=+\-|;:\'\"\/])*[^\s]\1*$/

Matches from the beginning of the line to the end. Accepts alphanumeric characters, numbers, and most special characters.

If you want just alphanumeric characters then change what is in the [] like so:

/^([A-z])*[^\s]\1*$/

Javascript Drag and drop for touch devices

I had the same solution as gregpress answer, but my draggable items used a class instead of an id. It seems to work.

var $target = $(event.target);  
if( $target.hasClass('draggable') ) {  
    event.preventDefault();  
}

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

Let's assume you have: function.apply(thisArg, argArray )

The apply method invokes a function, passing in the object that will be bound to this and an optional array of arguments.

The slice() method selects a part of an array, and returns the new array.

So when you call Array.prototype.slice.apply(arguments, [0]) the array slice method is invoked (bind) on arguments.

Convert Python ElementTree to string

If you just need this for debugging to see how the XML looks like, then instead of print(xml.etree.ElementTree.tostring(e)) you can use dump like this:

xml.etree.ElementTree.dump(e)

And this works both with Element and ElementTree objects as e, so there should be no need for getroot.

The documentation of dump says:

xml.etree.ElementTree.dump(elem)

Writes an element tree or element structure to sys.stdout. This function should be used for debugging only.

The exact output format is implementation dependent. In this version, it’s written as an ordinary XML file.

elem is an element tree or an individual element.

Changed in version 3.8: The dump() function now preserves the attribute order specified by the user.

Recover from git reset --hard?

I found out the hard way that any uncommitted files before a git reset --hard <commit> gets removed from git history. However, I was lucky enough to have kept my code editor session open during the entire time I was pulling my hair out, that I discovered that a simple control + z in each of the affected files returned the state of the file back to the version before Git so obligingly reset everything I didn't ask it to specifically. Hooray!!

Does Visual Studio Code have box select/multi-line edit?

Press Ctrl+Alt+Down or Ctrl+Alt+Up to insert cursors below or above.

Installing SetupTools on 64-bit Windows

Get the file register.py from this gist. Save it on your C drive or D drive, go to CMD to run it with:

'python register.py'

Then you will be able to install it.

Good Patterns For VBA Error Handling

Here's a pretty decent pattern.

For debugging: When an error is raised, hit Ctrl-Break (or Ctrl-Pause), drag the break marker (or whatever it's called) down to the Resume line, hit F8 and you'll step to the line that "threw" the error.

The ExitHandler is your "Finally".

Hourglass will be killed every time. Status bar text will be cleared every time.

Public Sub ErrorHandlerExample()
    Dim dbs As DAO.Database
    Dim rst As DAO.Recordset

    On Error GoTo ErrHandler
    Dim varRetVal As Variant

    Set dbs = CurrentDb
    Set rst = dbs.OpenRecordset("SomeTable", dbOpenDynaset, dbSeeChanges + dbFailOnError)

    Call DoCmd.Hourglass(True)

    'Do something with the RecordSet and close it.

    Call DoCmd.Hourglass(False)

ExitHandler:
    Set rst = Nothing
    Set dbs = Nothing
    Exit Sub

ErrHandler:
    Call DoCmd.Hourglass(False)
    Call DoCmd.SetWarnings(True)
    varRetVal = SysCmd(acSysCmdClearStatus)

    Dim errX As DAO.Error
    If Errors.Count > 1 Then
       For Each errX In DAO.Errors
          MsgBox "ODBC Error " & errX.Number & vbCrLf & errX.Description
       Next errX
    Else
        MsgBox "VBA Error " & Err.Number & ": " & vbCrLf & Err.Description & vbCrLf & "In: Form_MainForm", vbCritical
    End If

    Resume ExitHandler
    Resume

End Sub



    Select Case Err.Number
        Case 3326 'This Recordset is not updateable
            'Do something about it. Or not...
        Case Else
            MsgBox "VBA Error " & Err.Number & ": " & vbCrLf & Err.Description & vbCrLf & "In: Form_MainForm", vbCritical
    End Select

It also traps for both DAO and VBA errors. You can put a Select Case in the VBA error section if you want to trap for specific Err numbers.

Select Case Err.Number
    Case 3326 'This Recordset is not updateable
        'Do something about it. Or not...
    Case Else
        MsgBox "VBA Error " & Err.Number & ": " & vbCrLf & Err.Description & vbCrLf & "In: Form_MainForm", vbCritical
End Select

Format Date time in AngularJS

Here are a few popular examples:

<div>{{myDate | date:'M/d/yyyy'}}</div> 7/4/2014

<div>{{myDate | date:'yyyy-MM-dd'}}</div> 2014-07-04

<div>{{myDate | date:'M/d/yyyy HH:mm:ss'}}</div> 7/4/2014 12:01:59

Remove a data connection from an Excel 2010 spreadsheet in compatibility mode

When the Import Data box pops up click on Properties and remove the Check Mark next to Save query definition When the Import Data box comes back and your location is where you want it to be (Ex: =$I$4) click on OK and your problem will be resolved

How to list only files and not directories of a directory Bash?

ls -p | grep -v /

ls -p lets you show / after the folder name, which acts as a tag for you to remove.

how to get file path from sd card in android

By using the following code you can find name, path, size as like this all kind of information of all audio song files

String[] STAR = { "*" };     
Uri allaudiosong = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
String audioselection = MediaStore.Audio.Media.IS_MUSIC + " != 0";
Cursor cursor;
cursor = managedQuery(allaudiosong, STAR, audioselection, null, null);

if (cursor != null) {
    if (cursor.moveToFirst()) {
        do {
            String song_name = cursor
                   .getString(cursor
                             .getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));
            System.out.println("Audio Song Name= "+song_name);

            int song_id = cursor.getInt(cursor
                    .getColumnIndex(MediaStore.Audio.Media._ID));
            System.out.println("Audio Song ID= "+song_id);

            String fullpath = cursor.getString(cursor
                    .getColumnIndex(MediaStore.Audio.Media.DATA));
            System.out.println("Audio Song FullPath= "+fullpath);

            String album_name = cursor.getString(cursor
                    .getColumnIndex(MediaStore.Audio.Media.ALBUM));
            System.out.println("Audio Album Name= "+album_name);

            int album_id = cursor.getInt(cursor
                    .getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));
            System.out.println("Audio Album Id= "+album_id);

            String artist_name = cursor.getString(cursor
                    .getColumnIndex(MediaStore.Audio.Media.ARTIST));
            System.out.println("Audio Artist Name= "+artist_name);

            int artist_id = cursor.getInt(cursor
                    .getColumnIndex(MediaStore.Audio.Media.ARTIST_ID));
            System.out.println("Audio Artist ID= "+artist_id);

        } while (cursor.moveToNext());

PHP Curl And Cookies

First create temporary cookie using tempnam() function:

$ckfile = tempnam ("/tmp", "CURLCOOKIE");

Then execute curl init witch saves the cookie as a temporary file:

$ch = curl_init ("http://uri.com/");
curl_setopt ($ch, CURLOPT_COOKIEJAR, $ckfile);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, true);
$output = curl_exec ($ch);

Or visit a page using the cookie stored in the temporary file:

$ch = curl_init ("http://somedomain.com/cookiepage.php");
curl_setopt ($ch, CURLOPT_COOKIEFILE, $ckfile);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, true);
$output = curl_exec ($ch);

This will initialize the cookie for the page:

curl_setopt ($ch, CURLOPT_COOKIEFILE, $ckfile);

Why does Maven have such a bad rep?

The biggest reason Maven has a bad rap is IDE integration. Yes, I know about m2eclipse. I like m2eclipse. I like Netbeans' integration even more.

Here's the problem. Some larger shops built tools to force Maven to work with things like RAD 7.0. It doesn't work well. These hackarounds exist to try to get Maven to behave inside of a tool they are not allowed to change (RAD 7.0). In my case the hackarounded maven builds only work inside Netbeans. Eclipse 3.5 with m2eclipse chokes something horrible.

Most of the devs here hate Maven. They don't hate Maven. They've never really used Maven.

It's disappointing, but it's not really Maven's fault. Maven worked more than fine for me in another life. Here, it's debilitating because of the IDE and the tools meant to make it usable fail to do so.

How to close a GUI when I push a JButton?

Create a method and call it to close the JFrame, for example:

public void CloseJframe(){
    super.dispose();
}

Delaying function in swift

 NSTimer.scheduledTimerWithTimeInterval(NSTimeInterval(3), target: self, selector: "functionHere", userInfo: nil, repeats: false)

This would call the function functionHere() with a 3 seconds delay

How can I get the index from a JSON object with value?

You can use Array.findIndex.

_x000D_
_x000D_
var data= [{
  "name": "placeHolder",
  "section": "right"
}, {
  "name": "Overview",
  "section": "left"
}, {
  "name": "ByFunction",
  "section": "left"
}, {
  "name": "Time",
  "section": "left"
}, {
  "name": "allFit",
  "section": "left"
}, {
  "name": "allbMatches",
  "section": "left"
}, {
  "name": "allOffers",
  "section": "left"
}, {
  "name": "allInterests",
  "section": "left"
}, {
  "name": "allResponses",
  "section": "left"
}, {
  "name": "divChanged",
  "section": "right"
}];
var index = data.findIndex(obj => obj.name=="allInterests");

console.log(index);
_x000D_
_x000D_
_x000D_

Better way to call javascript function in a tag

Some advantages to the second option:

  1. You can use this inside onclick to reference the anchor itself (doing the same in option 1 will give you window instead).

  2. You can set the href to a non-JS compatible URL to support older browsers (or those that have JS disabled); browsers that support JavaScript will execute the function instead (to stay on the page you have to use onclick="return someFunction();" and return false from inside the function or onclick="return someFunction(); return false;" to prevent default action).

  3. I've seen weird stuff happen when using href="javascript:someFunction()" and the function returns a value; the whole page would get replaced by just that value.

Pitfalls

Inline code:

  1. Runs in document scope as opposed to code defined inside <script> tags which runs in window scope; therefore, symbols may be resolved based on an element's name or id attribute, causing the unintended effect of attempting to treat an element as a function.

  2. Is harder to reuse; delicate copy-paste is required to move it from one project to another.

  3. Adds weight to your pages, whereas external code files can be cached by the browser.

Is there a 'foreach' function in Python 3?

This does the foreach in python 3

test = [0,1,2,3,4,5,6,7,8,"test"]

for fetch in test:
    print(fetch)

NOT IN vs NOT EXISTS

Actually, I believe this would be the fastest:

SELECT ProductID, ProductName 
    FROM Northwind..Products p  
          outer join Northwind..[Order Details] od on p.ProductId = od.ProductId)
WHERE od.ProductId is null

Regex expressions in Java, \\s vs. \\s+

The first one matches a single whitespace, whereas the second one matches one or many whitespaces. They're the so-called regular expression quantifiers, and they perform matches like this (taken from the documentation):

Greedy quantifiers
X?  X, once or not at all
X*  X, zero or more times
X+  X, one or more times
X{n}    X, exactly n times
X{n,}   X, at least n times
X{n,m}  X, at least n but not more than m times

Reluctant quantifiers
X?? X, once or not at all
X*? X, zero or more times
X+? X, one or more times
X{n}?   X, exactly n times
X{n,}?  X, at least n times
X{n,m}? X, at least n but not more than m times

Possessive quantifiers
X?+ X, once or not at all
X*+ X, zero or more times
X++ X, one or more times
X{n}+   X, exactly n times
X{n,}+  X, at least n times
X{n,m}+ X, at least n but not more than m times

How to find time complexity of an algorithm

Although there are some good answers for this question. I would like to give another answer here with several examples of loop.

  • O(n): Time Complexity of a loop is considered as O(n) if the loop variables is incremented / decremented by a constant amount. For example following functions have O(n) time complexity.

    // Here c is a positive integer constant   
    for (int i = 1; i <= n; i += c) {  
        // some O(1) expressions
    }
    
    for (int i = n; i > 0; i -= c) {
        // some O(1) expressions
    }
    
  • O(n^c): Time complexity of nested loops is equal to the number of times the innermost statement is executed. For example the following sample loops have O(n^2) time complexity

    for (int i = 1; i <=n; i += c) {
       for (int j = 1; j <=n; j += c) {
          // some O(1) expressions
       }
    }
    
    for (int i = n; i > 0; i += c) {
       for (int j = i+1; j <=n; j += c) {
          // some O(1) expressions
    }
    

    For example Selection sort and Insertion Sort have O(n^2) time complexity.

  • O(Logn) Time Complexity of a loop is considered as O(Logn) if the loop variables is divided / multiplied by a constant amount.

    for (int i = 1; i <=n; i *= c) {
       // some O(1) expressions
    }
    for (int i = n; i > 0; i /= c) {
       // some O(1) expressions
    }
    

    For example Binary Search has O(Logn) time complexity.

  • O(LogLogn) Time Complexity of a loop is considered as O(LogLogn) if the loop variables is reduced / increased exponentially by a constant amount.

    // Here c is a constant greater than 1   
    for (int i = 2; i <=n; i = pow(i, c)) { 
       // some O(1) expressions
    }
    //Here fun is sqrt or cuberoot or any other constant root
    for (int i = n; i > 0; i = fun(i)) { 
       // some O(1) expressions
    }
    

One example of time complexity analysis

int fun(int n)
{    
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j < n; j += i)
        {
            // Some O(1) task
        }
    }    
}

Analysis:

For i = 1, the inner loop is executed n times. For i = 2, the inner loop is executed approximately n/2 times. For i = 3, the inner loop is executed approximately n/3 times. For i = 4, the inner loop is executed approximately n/4 times. ……………………………………………………. For i = n, the inner loop is executed approximately n/n times.

So the total time complexity of the above algorithm is (n + n/2 + n/3 + … + n/n), Which becomes n * (1/1 + 1/2 + 1/3 + … + 1/n)

The important thing about series (1/1 + 1/2 + 1/3 + … + 1/n) is equal to O(Logn). So the time complexity of the above code is O(nLogn).


Ref: 1 2 3

Get img thumbnails from Vimeo?

In javascript (uses jQuery):

function vimeoLoadingThumb(id){    
    var url = "http://vimeo.com/api/v2/video/" + id + ".json?callback=showThumb";

    var id_img = "#vimeo-" + id;

    var script = document.createElement( 'script' );
    script.src = url;

    $(id_img).before(script);
}


function showThumb(data){
    var id_img = "#vimeo-" + data[0].id;
    $(id_img).attr('src',data[0].thumbnail_medium);
}

To display it :

<img id="vimeo-{{ video.id_video }}" src="" alt="{{ video.title }}" />
<script type="text/javascript">
  vimeoLoadingThumb({{ video.id_video }});
</script>

GROUP_CONCAT comma separator - MySQL

Query to achieve your requirment

SELECT id,GROUP_CONCAT(text SEPARATOR ' ') AS text FROM table_name group by id;

How do I get which JRadioButton is selected from a ButtonGroup

I would just loop through your JRadioButtons and call isSelected(). If you really want to go from the ButtonGroup you can only get to the models. You could match the models to the buttons, but then if you have access to the buttons, why not use them directly?

What jsf component can render a div tag?

In JSF 2.2 it's possible to use passthrough elements:

<html xmlns="http://www.w3.org/1999/xhtml"
  xmlns:jsf="http://xmlns.jcp.org/jsf">
    ...
    <div jsf:id="id1" />
    ...
</html>

The requirement is to have at least one attribute in the element using jsf namespace.

jQuery if div contains this text, replace that part of the text

You can use the contains selector to search for elements containing a specific text

var elem = $('div.text_div:contains("This div contains some text")')?;
elem.text(elem.text().replace("contains", "Hello everyone"));

??????????????????????????????????????????

Apply function to all elements of collection through LINQ

Or you can hack it up.

Items.All(p => { p.IsAwesome = true; return true; });

Getting the HTTP Referrer in ASP.NET

Request.Headers["Referer"]

Explanation

The Request.UrlReferer property will throw a System.UriFormatException if the referer HTTP header is malformed (which can happen since it is not usually under your control).

Therefore, the Request.UrlReferer property is not 100% reliable - it may contain data that cannot be parsed into a Uri class. To ensure the value is always readable, use Request.Headers["Referrer"] instead.

As for using Request.ServerVariables as others here have suggested, per MSDN:

Request.ServerVariables Collection

The ServerVariables collection retrieves the values of predetermined environment variables and request header information.

Request.Headers Property

Gets a collection of HTTP headers.

Request.Headers is a better choice than Request.ServerVariables, since Request.ServerVariables contains all of the environment variables as well as the headers, where Request.Headers is a much shorter list that only contains the headers.

So the most reliable solution is to use the Request.Headers collection to read the value directly. Do heed Microsoft's warnings about HTML encoding the value if you are going to display it on a form, though.

Add onClick event to document.createElement("th")

var newTH = document.createElement('th');
newTH.setAttribute("onclick", "removeColumn(#)");
newTH.setAttribute("id", "#");

function removeColumn(#){
// remove column #
}

Is double square brackets [[ ]] preferable over single square brackets [ ] in Bash?

From Which comparator, test, bracket, or double bracket, is fastest? (http://bashcurescancer.com)

The double bracket is a “compound command” where as test and the single bracket are shell built-ins (and in actuality are the same command). Thus, the single bracket and double bracket execute different code.

The test and single bracket are the most portable as they exist as separate and external commands. However, if your using any remotely modern version of BASH, the double bracket is supported.

java : convert float to String and String to float

There are three ways to convert float to String.

  1. "" + f
  2. Float.toString(f)
  3. String.valueOf(f)

There are two ways Convert String to float

  1. Float.valueOf(str)
  2. Float.parseFloat(str);

Example:-

public class Test {

    public static void main(String[] args) {
        System.out.println("convert FloatToString " + convertFloatToString(34.0f));

        System.out.println("convert FloatToStr Using Float Method " + convertFloatToStrUsingFloatMethod(23.0f));

        System.out.println("convert FloatToStr Using String Method " + convertFloatToStrUsingFloatMethod(233.0f));

        float f = Float.valueOf("23.00");
    }

    public static String convertFloatToString(float f) {
        return "" + f;
    }

    public static String convertFloatToStrUsingFloatMethod(float f) {
        return Float.toString(f);
    }

    public static String convertFloatToStrUsingStringMethod(float f) {
        return String.valueOf(f);
    }

}

Android: Access child views from a ListView

listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, final View view, int position, long id) {
        View v;
        int count = parent.getChildCount();
        v = parent.getChildAt(position);
        parent.requestChildFocus(v, view);
        v.setBackground(res.getDrawable(R.drawable.transparent_button));
        for (int i = 0; i < count; i++) {
            if (i != position) {
                v = parent.getChildAt(i);
                v.setBackground(res.getDrawable(R.drawable.not_clicked));
            }
        }
    }
});

Basically, create two Drawables - one that is transparent, and another that is the desired color. Request focus at the clicked position (int position as defined) and change the color of the said row. Then walk through the parent ListView, and change all other rows accordingly. This accounts for when a user clicks on the listview multiple times. This is done with a custom layout for each row in the ListView. (Very simple, just create a new layout file with a TextView - do not set focusable or clickable!).

No custom adapter required - use ArrayAdapter

Replacing backslashes with forward slashes with str_replace() in php

You need to escape backslash with a \

  $str = str_replace ("\\", "/", $str);

Scala Doubles, and Precision

A bit strange but nice. I use String and not BigDecimal

def round(x: Double)(p: Int): Double = {
    var A = x.toString().split('.')
    (A(0) + "." + A(1).substring(0, if (p > A(1).length()) A(1).length() else p)).toDouble
}

Error 'tunneling socket' while executing npm install

If you using gnome, and turned off the proxy at the network level, you also need to make sure you don't have proxy enabled in your terminal

? gconftool-2 -a /system/http_proxy  
 host = http://localhost/
 port = 2000
 use_http_proxy = false
 use_authentication = false
 authentication_password = 
 authentication_user = 
 ignore_hosts = [localhost,127.0.0.0/8]

You can drop it with

gconftool-2 -t string -s /system/http_proxy/host ""
gconftool-2 -u /system/http_proxy/port
gconftool-2 -u /system/http_proxy/host
unset http_proxy

Laravel 5 – Remove Public from URL

BEST Approach: I will not recommend removing public, instead on local computer create a virtual host point to public directory and on remote hosting change public to public_html and point your domain to this directory. Reason, your whole laravel code will be secure because its one level down to your public directory :)

METHOD 1:

I just rename server.php to index.php and it works

METHOD 2:

This work well for all laravel version...

Here is my Directory Structure,

/laravel/
... app
... bootstrap
... public
... etc

Follow these easy steps

  1. move all files from public directory to root /laravel/
  2. now, no need of public directory, so optionally you can remove it now
  3. now open index.php and make following replacements

require DIR.'/../bootstrap/autoload.php';

to

require DIR.'/bootstrap/autoload.php';

and

$app = require_once DIR.'/../bootstrap/start.php';

to

$app = require_once DIR.'/bootstrap/start.php';

  1. now open bootstrap/paths.php and change public directory path:

'public' => DIR.'/../public',

to

'public' => DIR.'/..',

and that's it, now try http:// localhost/laravel/

How to check if a column exists in Pandas

This will work:

if 'A' in df:

But for clarity, I'd probably write it as:

if 'A' in df.columns:

How to detect Safari, Chrome, IE, Firefox and Opera browser?

Simple, single line of JavaScript code will give you the name of browser:

function GetBrowser()
{
    return  navigator ? navigator.userAgent.toLowerCase() : "other";
}

ERROR Error: StaticInjectorError(AppModule)[UserformService -> HttpClient]:

There are two possible reasons 1. If you are using HttpClient in your service you need to import HttpClientModule in your module file and mention it in the imports array.

import { HttpClientModule } from '@angular/common/http';
  1. If you are using normal Http in your services you need to import HttpModule in your module file and mention it in the imports array.

    import { HttpModule } from '@angular/http'

By default, this is not available in the angular then you need to install @angular/http

If you wish you can use both HttpClientModule and HttpModule in your project.

Connect to SQL Server Database from PowerShell

Change Integrated security to false in the connection string.

You can check/verify this by opening up the SQL management studio with the username/password you have and see if you can connect/open the database from there. NOTE! Could be a firewall issue as well.

Python - Create list with numbers between 2 values?

I got here because I wanted to create a range between -10 and 10 in increments of 0.1 using list comprehension. Instead of doing an overly complicated function like most of the answers above I just did this

simple_range = [ x*0.1 for x in range(-100, 100) ]

By changing the range count to 100 I now get my range of -10 through 10 by using the standard range function. So if you need it by 0.2 then just do range(-200, 200) and so on etc