Programs & Examples On #Findname

Accessing a resource via codebehind in WPF

You may also use this.Resources["mykey"]. I guess that is not much better than your own suggestion.

C++ calling base class constructors

The short answer for this is, "because that's what the C++ standard specifies".

Note that you can always specify a constructor that's different from the default, like so:

class Shape  {

  Shape()  {...} //default constructor
  Shape(int h, int w) {....} //some custom constructor


};

class Rectangle : public Shape {
  Rectangle(int h, int w) : Shape(h, w) {...} //you can specify which base class constructor to call

}

The default constructor of the base class is called only if you don't specify which one to call.

How do I enable index downloads in Eclipse for Maven dependency search?

  1. In Eclipse, click on Windows > Preferences, and then choose Maven in the left side.
  2. Check the box "Download repository index updates on startup".
    • Optionally, check the boxes Download Artifact Sources and Download Artifact JavaDoc.
  3. Click OK. The warning won't appear anymore.
  4. Restart Eclipse.

http://i.imgur.com/IJ2T3vc.png

What is the __del__ method, How to call it?

I wrote up the answer for another question, though this is a more accurate question for it.

How do constructors and destructors work?

Here is a slightly opinionated answer.

Don't use __del__. This is not C++ or a language built for destructors. The __del__ method really should be gone in Python 3.x, though I'm sure someone will find a use case that makes sense. If you need to use __del__, be aware of the basic limitations per http://docs.python.org/reference/datamodel.html:

  • __del__ is called when the garbage collector happens to be collecting the objects, not when you lose the last reference to an object and not when you execute del object.
  • __del__ is responsible for calling any __del__ in a superclass, though it is not clear if this is in method resolution order (MRO) or just calling each superclass.
  • Having a __del__ means that the garbage collector gives up on detecting and cleaning any cyclic links, such as losing the last reference to a linked list. You can get a list of the objects ignored from gc.garbage. You can sometimes use weak references to avoid the cycle altogether. This gets debated now and then: see http://mail.python.org/pipermail/python-ideas/2009-October/006194.html.
  • The __del__ function can cheat, saving a reference to an object, and stopping the garbage collection.
  • Exceptions explicitly raised in __del__ are ignored.
  • __del__ complements __new__ far more than __init__. This gets confusing. See http://www.algorithm.co.il/blogs/programming/python-gotchas-1-del-is-not-the-opposite-of-init/ for an explanation and gotchas.
  • __del__ is not a "well-loved" child in Python. You will notice that sys.exit() documentation does not specify if garbage is collected before exiting, and there are lots of odd issues. Calling the __del__ on globals causes odd ordering issues, e.g., http://bugs.python.org/issue5099. Should __del__ called even if the __init__ fails? See http://mail.python.org/pipermail/python-dev/2000-March/thread.html#2423 for a long thread.

But, on the other hand:

And my pesonal reason for not liking the __del__ function.

  • Everytime someone brings up __del__ it devolves into thirty messages of confusion.
  • It breaks these items in the Zen of Python:
    • Simple is better than complicated.
    • Special cases aren't special enough to break the rules.
    • Errors should never pass silently.
    • In the face of ambiguity, refuse the temptation to guess.
    • There should be one – and preferably only one – obvious way to do it.
    • If the implementation is hard to explain, it's a bad idea.

So, find a reason not to use __del__.

Getting error while sending email through Gmail SMTP - "Please log in via your web browser and then try again. 534-5.7.14"

To send mail using Gmail SMTP, need to change your account setting. Login into your gmail accout then follow the link below to change your gmail account setting to send mail using your apps and program. https://www.google.com/settings/security/lesssecureapps

Note: This setting is not available for accounts with 2-Step Verification enabled. Such accounts require an application-specific password for less secure apps access.

Does Python have a string 'contains' substring method?

if needle in haystack: is the normal use, as @Michael says -- it relies on the in operator, more readable and faster than a method call.

If you truly need a method instead of an operator (e.g. to do some weird key= for a very peculiar sort...?), that would be 'haystack'.__contains__. But since your example is for use in an if, I guess you don't really mean what you say;-). It's not good form (nor readable, nor efficient) to use special methods directly -- they're meant to be used, instead, through the operators and builtins that delegate to them.

Using msbuild to execute a File System Publish Profile

Run from the project folder

msbuild /p:DeployOnBuild=true /p:PublishProfile="release-file.pubxml" /p:AspnetMergePath="C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.8 Tools" /p:Configuration=Release

This takes care of web.config Transform and AspnetMergePath

Processing $http response in service

Let it be simple. It's as simple as

  1. Return promise in your service(no need to use then in service)
  2. Use then in your controller

Demo. http://plnkr.co/edit/cbdG5p?p=preview

var app = angular.module('plunker', []);

app.factory('myService', function($http) {
  return {
    async: function() {
      return $http.get('test.json');  //1. this returns promise
    }
  };
});

app.controller('MainCtrl', function( myService,$scope) {
  myService.async().then(function(d) { //2. so you can use .then()
    $scope.data = d;
  });
});

Filter an array using a formula (without VBA)

Today, in Office 365, Excel has so called 'array functions'. The filter function does exactly what you want. No need to use CTRL+SHIFT+ENTER anymore, a simple enter will suffice.

In Office 365, your problem would be simply solved by using:

=VLOOKUP(A3, FILTER(A2:C6, B2:B6="B"), 3, FALSE)

A function to convert null to string

public string nullToString(string value)
{
    return value == null ?string.Empty: value;   
}

How to terminate the script in JavaScript?

If you use any undefined function in the script then script will stop due to "Uncaught ReferenceError". I have tried by following code and first two lines executed.

I think, this is the best way to stop the script. If there's any other way then please comment me. I also want to know another best and simple way. BTW, I didn't get exit or die inbuilt function in Javascript like PHP for terminate the script. If anyone know then please let me know.

alert('Hello');

document.write('Hello User!!!');

die();  //Uncaught ReferenceError: die is not defined

alert('bye');

document.write('Bye User!!!');

How to echo shell commands as they are executed

For zsh, echo

setopt VERBOSE

And for debugging,

setopt XTRACE

For loop in Oracle SQL

You will certainly be able to do that using WITH clause, or use analytic functions available in Oracle SQL.

With some effort you'd be able to get anything out of them in terms of cycles as in ordinary procedural languages. Both approaches are pretty powerful compared to ordinary SQL.

http://www.dba-oracle.com/t_with_clause.htm

http://www.orafaq.com/node/55

It requires some effort though. Don't be afraid to post a concrete example.

Using simple pseudo table DUAL helps too.

Configuring IntelliJ IDEA for unit testing with JUnit

Press Ctrl+Shift+T in the code editor. It will show you popup with suggestion to create a test.

Mac OS: ? Cmd+Shift+T

Char array to hex string C++

You could use std::hex

Eg.

std::cout << std::hex << packet;

How to limit text width

 display: inline-block;
max-width: 80%;
height: 1.5em;
overflow: hidden;
text-overflow: ellipsis;
white-space: nowrap; 

How do you convert CString and std::string std::wstring to each other?

If you want something more C++-like, this is what I use. Although it depends on Boost, that's just for exceptions. You can easily remove those leaving it to depend only on the STL and the WideCharToMultiByte() Win32 API call.

#include <string>
#include <vector>
#include <cassert>
#include <exception>

#include <boost/system/system_error.hpp>
#include <boost/integer_traits.hpp>

/**
 * Convert a Windows wide string to a UTF-8 (multi-byte) string.
 */
std::string WideStringToUtf8String(const std::wstring& wide)
{
    if (wide.size() > boost::integer_traits<int>::const_max)
        throw std::length_error(
            "Wide string cannot be more than INT_MAX characters long.");
    if (wide.size() == 0)
        return "";

    // Calculate necessary buffer size
    int len = ::WideCharToMultiByte(
        CP_UTF8, 0, wide.c_str(), static_cast<int>(wide.size()), 
        NULL, 0, NULL, NULL);

    // Perform actual conversion
    if (len > 0)
    {
        std::vector<char> buffer(len);
        len = ::WideCharToMultiByte(
            CP_UTF8, 0, wide.c_str(), static_cast<int>(wide.size()),
            &buffer[0], static_cast<int>(buffer.size()), NULL, NULL);
        if (len > 0)
        {
            assert(len == static_cast<int>(buffer.size()));
            return std::string(&buffer[0], buffer.size());
        }
    }

    throw boost::system::system_error(
        ::GetLastError(), boost::system::system_category);
}

XmlSerializer giving FileNotFoundException at constructor

Function XmlSerializer.FromTypes does not throw the exception, but it leaks the memory. Thats why you need to cache such serializer for every type to avoid memory leaking for every instance created.

Create your own XmlSerializer factory and use it simply:

XmlSerializer serializer = XmlSerializerFactoryNoThrow.Create(typeof(MyType));

The factory looks likes:

public static class XmlSerializerFactoryNoThrow
{
    public static Dictionary<Type, XmlSerializer> _cache = new Dictionary<Type, XmlSerializer>();

    private static object SyncRootCache = new object();        

    /// <summary>
    /// //the constructor XmlSerializer.FromTypes does not throw exception, but it is said that it causes memory leaks
    /// http://stackoverflow.com/questions/1127431/xmlserializer-giving-filenotfoundexception-at-constructor
    /// That is why I use dictionary to cache the serializers my self.
    /// </summary>
    public static XmlSerializer Create(Type type)
    {
        XmlSerializer serializer;

        lock (SyncRootCache)
        {
            if (_cache.TryGetValue(type, out serializer))
                return serializer;
        }

        lock (type) //multiple variable of type of one type is same instance
        {
            //constructor XmlSerializer.FromTypes does not throw the first chance exception           
            serializer = XmlSerializer.FromTypes(new[] { type })[0];
            //serializer = XmlSerializerFactoryNoThrow.Create(type);
        }

        lock (SyncRootCache)
        {
            _cache[type] = serializer;
        }
        return serializer;
    }       
}

More complicated version without possibility of memory leak (please someone review the code):

    public static XmlSerializer Create(Type type)
    {
        XmlSerializer serializer;

        lock (SyncRootCache)
        {
            if (_cache.TryGetValue(type, out serializer))
                return serializer;
        }

        lock (type) //multiple variable of type of one type is same instance
        {
            lock (SyncRootCache)
            {
                if (_cache.TryGetValue(type, out serializer))
                    return serializer;
            }
            serializer = XmlSerializer.FromTypes(new[] { type })[0];
            lock (SyncRootCache)
            {
                _cache[type] = serializer;
            }
        }          
        return serializer;
    }       
}

jQuery textbox change event

There is no real solution to this - even in the links to other questions given above. In the end I have decided to use setTimeout and call a method that checks every second! Not an ideal solution, but a solution that works and code I am calling is simple enough to not have an effect on performance by being called all the time.

function InitPageControls() {
        CheckIfChanged();
    }

    function CheckIfChanged() {
        // do logic

        setTimeout(function () {
            CheckIfChanged();
        }, 1000);
    }

Hope this helps someone in the future as it seems there is no surefire way of acheiving this using event handlers...

Should Gemfile.lock be included in .gitignore?

The other answers here are correct: Yes, your Ruby app (not your Ruby gem) should include Gemfile.lock in the repo. To expand on why it should do this, read on:

I was under the mistaken notion that each env (development, test, staging, prod...) each did a bundle install to build their own Gemfile.lock. My assumption was based on the fact that Gemfile.lock does not contain any grouping data, such as :test, :prod, etc. This assumption was wrong, as I found out in a painful local problem.

Upon closer investigation, I was confused why my Jenkins build showed fetching a particular gem (ffaker, FWIW) successfully, but when the app loaded and required ffaker, it said file not found. WTF?

A little more investigation and experimenting showed what the two files do:

First it uses Gemfile.lock to go fetch all the gems, even those that won't be used in this particular env. Then it uses Gemfile to choose which of those fetched gems to actually use in this env.

So, even though it fetched the gem in the first step based on Gemfile.lock, it did NOT include in my :test environment, based on the groups in Gemfile.

The fix (in my case) was to move gem 'ffaker' from the :development group to the main group, so all env's could use it. (Or, add it only to :development, :test, as appropriate)

How to apply an XSLT Stylesheet in C#

Based on Daren's excellent answer, note that this code can be shortened significantly by using the appropriate XslCompiledTransform.Transform overload:

var myXslTrans = new XslCompiledTransform(); 
myXslTrans.Load("stylesheet.xsl"); 
myXslTrans.Transform("source.xml", "result.html"); 

(Sorry for posing this as an answer, but the code block support in comments is rather limited.)

In VB.NET, you don't even need a variable:

With New XslCompiledTransform()
    .Load("stylesheet.xsl")
    .Transform("source.xml", "result.html")
End With

Best way to find if an item is in a JavaScript array?

A robust way to check if an object is an array in javascript is detailed here:

Here are two functions from the xa.js framework which I attach to a utils = {} ‘container’. These should help you properly detect arrays.

var utils = {};

/**
 * utils.isArray
 *
 * Best guess if object is an array.
 */
utils.isArray = function(obj) {
     // do an instanceof check first
     if (obj instanceof Array) {
         return true;
     }
     // then check for obvious falses
     if (typeof obj !== 'object') {
         return false;
     }
     if (utils.type(obj) === 'array') {
         return true;
     }
     return false;
 };

/**
 * utils.type
 *
 * Attempt to ascertain actual object type.
 */
utils.type = function(obj) {
    if (obj === null || typeof obj === 'undefined') {
        return String (obj);
    }
    return Object.prototype.toString.call(obj)
        .replace(/\[object ([a-zA-Z]+)\]/, '$1').toLowerCase();
};

If you then want to check if an object is in an array, I would also include this code:

/**
 * Adding hasOwnProperty method if needed.
 */
if (typeof Object.prototype.hasOwnProperty !== 'function') {
    Object.prototype.hasOwnProperty = function (prop) {
        var type = utils.type(this);
        type = type.charAt(0).toUpperCase() + type.substr(1);
        return this[prop] !== undefined
            && this[prop] !== window[type].prototype[prop];
    };
}

And finally this in_array function:

function in_array (needle, haystack, strict) {
    var key;

    if (strict) {
        for (key in haystack) {
            if (!haystack.hasOwnProperty[key]) continue;

            if (haystack[key] === needle) {
                return true;
            }
        }
    } else {
        for (key in haystack) {
            if (!haystack.hasOwnProperty[key]) continue;

            if (haystack[key] == needle) {
                return true;
            }
        }
    }

    return false;
}

How to hide reference counts in VS2013?

I guess you probably are running the preview of VS2013 Ultimate, because it is not present in my professional preview. But looking online I found that the feature is called Code Information Indicators or CodeLens, and can be located under

Tools ? Options ? Text Editor ? All Languages ? CodeLens

(for RC/final version)

or

Tools ? Options ? Text Editor ? All Languages ? Code Information Indicators

(for preview version)

That was according to this link. It seems to be pretty well hidden.

In Visual Studio 2013 RTM, you can also get to the CodeLens options by right clicking the indicators themselves in the editor:

editor options

documented in the Q&A section of the msdn CodeLens documentation

How to get past the login page with Wget?

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

How to view query error in PDO PHP

I'm using this without any additional settings:

if (!$st->execute()) {
    print_r($st->errorInfo());
}

Is it good practice to use the xor operator for boolean checks?

With code clarity in mind, my opinion is that using XOR in boolean checks is not typical usage for the XOR bitwise operator. From my experience, bitwise XOR in Java is typically used to implement a mask flag toggle behavior:

flags = flags ^ MASK;

This article by Vipan Singla explains the usage case more in detail.

If you need to use bitwise XOR as in your example, comment why you use it, since it's likely to require even a bitwise literate audience to stop in their tracks to understand why you are using it.

Get gateway ip address in android

Install terminal emulator app, then to see routing table run iproute from the command prompt. Does not require root permissions. I don't know how to get the DNS server. There's no /etc/resolv.conf file. You can try nslookup www.google.com and see what it reports for your server, but on my phone it reports 0.0.0.0 which isn't too helpful.

JSON.NET Error Self referencing loop detected for type

I had this exception and my working solution is Easy and Simple,

Ignore the Referenced property by adding the JsonIgnore attribute to it:

[JsonIgnore]
public MyClass currentClass { get; set; }

Reset the property when you Deserialize it:

Source = JsonConvert.DeserializeObject<MyObject>(JsonTxt);
foreach (var item in Source)
        {
            Source.MyClass = item;
        }

using Newtonsoft.Json;

$_SERVER['HTTP_REFERER'] missing

function redirectHome($theMsg, $url = null, $seconds = 3) {
    if ($url === null) {
        $url  = 'index.php';
        $link = 'Homepage';
    } else {
        if (isset($_SERVER['HTTP_REFERER']) && $_SERVER['HTTP_REFERER'] !== '') {
            $url = $_SERVER['HTTP_REFERER'];
            $link = 'Previous Page';
        } else {
            $url = 'index.php';
            $link = 'Homepage';
        }
    }
    echo $theMsg;
    echo "<div class='alert alert-info'>You Will Be Redirected to $link After $seconds Seconds.</div>";
    header("refresh:$seconds;url=$url");
    exit();
}

ListBox with ItemTemplate (and ScrollBar!)

ListBox will try to expand in height that is available.. When you set the Height property of ListBox you get a scrollviewer that actually works...

If you wish your ListBox to accodate the height available, you might want to try to regulate the Height from your parent controls.. In a Grid for example, setting the Height to Auto in your RowDefinition might do the trick...

HTH

How to install Android SDK on Ubuntu?

sudo add-apt-repository -y ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java7-installer oracle-java7-set-default
wget https://dl.google.com/dl/android/studio/ide-zips/2.2.0.12/android-studio-ide-145.3276617-linux.zip
unzip android-studio-ide-145.3276617-linux.zip
cd android-studio/bin
./studio.sh

Scroll Element into View with Selenium

In most of the situation for scrolling this code will work.

WebElement element = driver.findElement(By.xpath("xpath_Of_Element"));                 
js.executeScript("arguments[0].click();",element);

Can I prevent text in a div block from overflowing?

If you want the overflowing text in the div to automatically newline instead of being hidden or making a scrollbar, use the

word-wrap: break-word

property.

reading HttpwebResponse json response, C#

I'd use RestSharp - https://github.com/restsharp/RestSharp

Create class to deserialize to:

public class MyObject {
    public string Id { get; set; }
    public string Text { get; set; }
    ...
}

And the code to get that object:

RestClient client = new RestClient("http://whatever.com");
RestRequest request = new RestRequest("path/to/object");
request.AddParameter("id", "123");

// The above code will make a request URL of 
// "http://whatever.com/path/to/object?id=123"
// You can pick and choose what you need

var response = client.Execute<MyObject>(request);

MyObject obj = response.Data;

Check out http://restsharp.org/ to get started.

Shortcut to comment out a block of code with sublime text

With a non-US keyboard layout the default shortcut Ctrl+/ (Win/Linux) does not work.

I managed to change it into Ctrl+1 as per Robert's comment by writing

[
{
    "keys": ["ctrl+1"],
    "command": "toggle_comment",
    "args": { "block": false } 
}
,
{   "keys": ["ctrl+shift+1"],
    "command": "toggle_comment",
    "args": { "block": true }
}
]

to Preferences -> Key Bindings (on the right half, the user keymap).

Note that there should be only one set of brackets ('[]') at the right side; if you had there something already, copy paste this between the brackets and keep only the outermost brackets.

How to create a pulse effect using -webkit-animation - outward rings

Or if you want a ripple pulse effect, you could use this:

http://jsfiddle.net/Fy8vD/3041/

.gps_ring {
     border: 2px solid #fff;
     -webkit-border-radius: 50%;
     height: 18px;
     width: 18px;
     position: absolute;
     left:20px;
    top:214px;
    -webkit-animation: pulsate 1s ease-out;
    -webkit-animation-iteration-count: infinite; 
    opacity: 0.0;
}
.gps_ring:before {
    content:"";
    display:block;
    border: 2px solid #fff;
    -webkit-border-radius: 50%;
    height: 30px;
    width: 30px;
    position: absolute;
    left:-8px;
    top:-8px;
    -webkit-animation: pulsate 1s ease-out;
    -webkit-animation-iteration-count: infinite; 
    -webkit-animation-delay: 0.1s;
    opacity: 0.0;
}
.gps_ring:after {
    content:"";
    display:block;
    border:2px solid #fff;
    -webkit-border-radius: 50%;
    height: 50px;
    width: 50px;
    position: absolute;
    left:-18px;
    top:-18px;
    -webkit-animation: pulsate 1s ease-out;
    -webkit-animation-iteration-count: infinite; 
    -webkit-animation-delay: 0.2s;
    opacity: 0.0;
}
@-webkit-keyframes pulsate {
    0% {-webkit-transform: scale(0.1, 0.1); opacity: 0.0;}
    50% {opacity: 1.0;}
    100% {-webkit-transform: scale(1.2, 1.2); opacity: 0.0;}
}

How to clear all input fields in a specific div with jQuery?

inspired from https://stackoverflow.com/a/10892768/2087666 but I use the selector instead of a class and prefer if over switch:

function clearAllInputs(selector) {
  $(selector).find(':input').each(function() {
    if(this.type == 'submit'){
          //do nothing
      }
      else if(this.type == 'checkbox' || this.type == 'radio') {
        this.checked = false;
      }
      else if(this.type == 'file'){
        var control = $(this);
        control.replaceWith( control = control.clone( true ) );
      }else{
        $(this).val('');
      }
   });
}

this should take care of almost all input inside any selector.

How can I compare two dates in PHP?

Found the answer on a blog and it's as simple as:

strtotime(date("Y"."-01-01")) -strtotime($newdate))/86400

And you'll get the days between the 2 dates.

What does #defining WIN32_LEAN_AND_MEAN exclude exactly?

According the to Windows Dev Center WIN32_LEAN_AND_MEAN excludes APIs such as Cryptography, DDE, RPC, Shell, and Windows Sockets.

SSH -L connection successful, but localhost port forwarding not working "channel 3: open failed: connect failed: Connection refused"

I had this problem when I wanted to make a vnc connection via a tunnel. But the vncserver was not running. I solved it by opening the channel on the remote machine with vncserver :3.

FragmentActivity to Fragment

first of all;

a Fragment must be inside a FragmentActivity, that's the first rule,

a FragmentActivity is quite similar to a standart Activity that you already know, besides having some Fragment oriented methods

second thing about Fragments, is that there is one important method you MUST call, wich is onCreateView, where you inflate your layout, think of it as the setContentLayout

here is an example:

    @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {     mView       = inflater.inflate(R.layout.fragment_layout, container, false);       return mView; } 

and continu your work based on that mView, so to find a View by id, call mView.findViewById(..);


for the FragmentActivity part:

the xml part "must" have a FrameLayout in order to inflate a fragment in it

        <FrameLayout             android:id="@+id/content_frame"             android:layout_width="match_parent"             android:layout_height="match_parent"  >         </FrameLayout> 

as for the inflation part

getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, new YOUR_FRAGMENT, "TAG").commit();


begin with these, as there is tons of other stuf you must know about fragments and fragment activities, start of by reading something about it (like life cycle) at the android developer site

Unicode, UTF, ASCII, ANSI format differences

Going down your list:

  • "Unicode" isn't an encoding, although unfortunately, a lot of documentation imprecisely uses it to refer to whichever Unicode encoding that particular system uses by default. On Windows and Java, this often means UTF-16; in many other places, it means UTF-8. Properly, Unicode refers to the abstract character set itself, not to any particular encoding.
  • UTF-16: 2 bytes per "code unit". This is the native format of strings in .NET, and generally in Windows and Java. Values outside the Basic Multilingual Plane (BMP) are encoded as surrogate pairs. These used to be relatively rarely used, but now many consumer applications will need to be aware of non-BMP characters in order to support emojis.
  • UTF-8: Variable length encoding, 1-4 bytes per code point. ASCII values are encoded as ASCII using 1 byte.
  • UTF-7: Usually used for mail encoding. Chances are if you think you need it and you're not doing mail, you're wrong. (That's just my experience of people posting in newsgroups etc - outside mail, it's really not widely used at all.)
  • UTF-32: Fixed width encoding using 4 bytes per code point. This isn't very efficient, but makes life easier outside the BMP. I have a .NET Utf32String class as part of my MiscUtil library, should you ever want it. (It's not been very thoroughly tested, mind you.)
  • ASCII: Single byte encoding only using the bottom 7 bits. (Unicode code points 0-127.) No accents etc.
  • ANSI: There's no one fixed ANSI encoding - there are lots of them. Usually when people say "ANSI" they mean "the default locale/codepage for my system" which is obtained via Encoding.Default, and is often Windows-1252 but can be other locales.

There's more on my Unicode page and tips for debugging Unicode problems.

The other big resource of code is unicode.org which contains more information than you'll ever be able to work your way through - possibly the most useful bit is the code charts.

How to Disable GUI Button in Java

Rather than using booleans, why not just set the button to false when its clicked, so you do that in your actionPerformed method. Its more efficient..

if (command.equals("w"))
{
    FileConverter fc = new FileConverter();
    btnConvertDocuments.setEnabled(false);
}

How to find if element with specific id exists or not

getElementById

Return Value: An Element Object, representing an element with the specified ID. Returns null if no elements with the specified ID exists see: https://www.w3schools.com/jsref/met_document_getelementbyid.asp

Truthy vs Falsy

In JavaScript, a truthy value is a value that is considered true when evaluated in a Boolean context. All values are truthy unless they are defined as falsy (i.e., except for false, 0, "", null, undefined, and NaN). see: https://developer.mozilla.org/en-US/docs/Glossary/Truthy

When the dom element is not found in the document it will return null. null is a Falsy and can be used as boolean expression in the if statement.

var myElement = document.getElementById("myElement");
if(myElement){
  // Element exists
}

How to count TRUE values in a logical vector

There's also a package called bit that is specifically designed for fast boolean operations. It's especially useful if you have large vectors or need to do many boolean operations.

z <- sample(c(TRUE, FALSE), 1e8, rep = TRUE)

system.time({
  sum(z) # 0.170s
})

system.time({
  bit::sum.bit(z) # 0.021s, ~10x improvement in speed
})

Is there a way to delete all the data from a topic or delete the topic before every run?

In manually deleting a topic from a kafka cluster , you just might check this out https://github.com/darrenfu/bigdata/issues/6 A vital step missed a lot in most solution is in deleting the /config/topics/<topic_name> in ZK.

How to check if another instance of my shell script is running

Here's how I do it in a bash script:

if ps ax | grep $0 | grep -v $$ | grep bash | grep -v grep
then
    echo "The script is already running."
    exit 1
fi

This allows me to use this snippet for any bash script. I needed to grep bash because when using with cron, it creates another process that executes it using /bin/sh.

Summing elements in a list

Python iterable can be summed like so - [sum(range(10)[1:])] . This sums all elements from the list except the first element.

>>> atuple = (1,2,3,4,5)
>>> sum(atuple)
15
>>> alist = [1,2,3,4,5]
>>> sum(alist)
15

CSS Always On Top

Ensure position is on your element and set the z-index to a value higher than the elements you want to cover.

element {
    position: fixed;
    z-index: 999;
}

div {
    position: relative;
    z-index: 99;
}

It will probably require some more work than that but it's a start since you didn't post any code.

iOS - Build fails with CocoaPods cannot find header files

I think an ultimate solution is to go to Build settings -> Search Path -> User Header Search Paths, find your library path and go through it in a Finder. Make sure that all path exists including your import path.

For me my path was shorter than in a tutorial. In tutorial it was something like #import <SDK/path/to/sdk/File.h>, but turns out it is just #import <SDK/File.h>

Conditional statement in a one line lambda function in python?

Use the exp1 if cond else exp2 syntax.

rate = lambda T: 200*exp(-T) if T>200 else 400*exp(-T)

Note you don't use return in lambda expressions.

How to completely remove Python from a Windows machine?

Windows 7 64-bit, with both Python3.4 and Python2.7 installed at some point :)

I'm using Py.exe to route to Py2 or Py3 depending on the script's needs - but I previously improperly uninstalled Python27 before.

Py27 was removed manually from C:\python\Python27 (the folder Python27 was deleted by me previously)

Upon re-installing Python27, it gave the above error you specify.
It would always back out while trying to 'remove shortcuts' during the installation process.

I placed a copy of Python27 back in that original folder, at C:\Python\Python27, and re-ran the same failing Python27 installer. It was happy locating those items and removing them, and proceeded with the install.

This is not the answer that addresses registry key issues (others mention that) but it is somewhat of a workaround if you know of previous installations that were improperly removed.

You could have some insight to this by opening "regedit" and searching for "Python27" - a registry key appeared in my command-shell Cache pointing at c:\python\python27\ (which had been removed and was not present when searching in the registry upon finding it).

That may help point to previously improperly removed installations.

Good luck!

Replace invalid values with None in Pandas DataFrame

where is probably what you're looking for. So

data=data.where(data=='-', None) 

From the panda docs:

where [returns] an object of same shape as self and whose corresponding entries are from self where cond is True and otherwise are from other).

Download old version of package with NuGet

In NuGet 3.0 the Get-Package command is deprecated and replaced with Find-Package command.

Find-Package Common.Logging -AllVersions

See the NuGet command reference docs for details.

This is the message shown if you try to use Get-Package in Visual Studio 2015.

This Command/Parameter combination has been deprecated and will be removed
in the next release. Please consider using the new command that replaces it: 
'Find-Package [-Id] -AllVersions'

Or as @Yishai said, you can use the version number dropdown in the NuGet screen in Visual Studio.

pandas GroupBy columns with NaN (missing) values

All answers provided thus far result in potentially dangerous behavior as it is quite possible you select a dummy value that is actually part of the dataset. This is increasingly likely as you create groups with many attributes. Simply put, the approach doesn't always generalize well.

A less hacky solve is to use pd.drop_duplicates() to create a unique index of value combinations each with their own ID, and then group on that id. It is more verbose but does get the job done:

def safe_groupby(df, group_cols, agg_dict):
    # set name of group col to unique value
    group_id = 'group_id'
    while group_id in df.columns:
        group_id += 'x'
    # get final order of columns
    agg_col_order = (group_cols + list(agg_dict.keys()))
    # create unique index of grouped values
    group_idx = df[group_cols].drop_duplicates()
    group_idx[group_id] = np.arange(group_idx.shape[0])
    # merge unique index on dataframe
    df = df.merge(group_idx, on=group_cols)
    # group dataframe on group id and aggregate values
    df_agg = df.groupby(group_id, as_index=True)\
               .agg(agg_dict)
    # merge grouped value index to results of aggregation
    df_agg = group_idx.set_index(group_id).join(df_agg)
    # rename index
    df_agg.index.name = None
    # return reordered columns
    return df_agg[agg_col_order]

Note that you can now simply do the following:

data_block = [np.tile([None, 'A'], 3),
              np.repeat(['B', 'C'], 3),
              [1] * (2 * 3)]

col_names = ['col_a', 'col_b', 'value']

test_df = pd.DataFrame(data_block, index=col_names).T

grouped_df = safe_groupby(test_df, ['col_a', 'col_b'],
                          OrderedDict([('value', 'sum')]))

This will return the successful result without having to worry about overwriting real data that is mistaken as a dummy value.

How can I copy columns from one sheet to another with VBA in Excel?

If you have merged cells,

Sub OneCell()
    Sheets("Sheet2").range("B1:B3").value = Sheets("Sheet1").range("A1:A3").value
End Sub

that doesn't copy cells as they are, where previous code does copy exactly as they look like (merged).

CSS position absolute full width problem

You could set both left and right property to 0. This will make the div stretch to the document width, but requires that no parent element is positioned (which is not the case, seeing as #header is position: relative;)

#site_nav_global_primary {    
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
}

Demo at: http://jsfiddle.net/xWnq2/, where I removed position:relative; from #header

Does WhatsApp offer an open API?

  1. is the correct answer. WhatsApp is intentionally a closed system without an API for external access.

There were several projects available that reverse engineered the WhatsApp webservice interfaces. However, to my knowledge all of them are now discontinued/defunct due to legal action against them from WhatsApp.

For mobile phone applications there is a limited URL-Scheme-API available on IPhone and Android (Android-intent possible as well).

What do \t and \b do?

No, that's more or less what they're meant to do.

In C (and many other languages), you can insert hard-to-see/type characters using \ notation:

  • \a is alert/bell
  • \b is backspace/rubout
  • \n is newline
  • \r is carriage return (return to left margin)
  • \t is tab

You can also specify the octal value of any character using \0nnn, or the hexadecimal value of any character with \xnn.

  • EG: the ASCII value of _ is octal 137, hex 5f, so it can also be typed \0137 or \x5f, if your keyboard didn't have a _ key or something. This is more useful for control characters like NUL (\0) and ESC (\033)

As someone posted (then deleted their answer before I could +1 it), there are also some less-frequently-used ones:

  • \f is a form feed/new page (eject page from printer)
  • \v is a vertical tab (move down one line, on the same column)

On screens, \f usually works the same as \v, but on some printers/teletypes, it will go all the way to the next form/sheet of paper.

Chaining multiple filter() in Django, is this a bug?

These two style of filtering are equivalent in most cases, but when query on objects base on ForeignKey or ManyToManyField, they are slightly different.

Examples from the documentation.

model
Blog to Entry is a one-to-many relation.

from django.db import models

class Blog(models.Model):
    ...

class Entry(models.Model):
    blog = models.ForeignKey(Blog)
    headline = models.CharField(max_length=255)
    pub_date = models.DateField()
    ...

objects
Assuming there are some blog and entry objects here.
enter image description here

queries

Blog.objects.filter(entry__headline_contains='Lennon', 
    entry__pub_date__year=2008)
Blog.objects.filter(entry__headline_contains='Lennon').filter(
    entry__pub_date__year=2008)  
    

For the 1st query (single filter one), it match only blog1.

For the 2nd query (chained filters one), it filters out blog1 and blog2.
The first filter restricts the queryset to blog1, blog2 and blog5; the second filter restricts the set of blogs further to blog1 and blog2.

And you should realize that

We are filtering the Blog items with each filter statement, not the Entry items.

So, it's not the same, because Blog and Entry are multi-valued relationships.

Reference: https://docs.djangoproject.com/en/1.8/topics/db/queries/#spanning-multi-valued-relationships
If there is something wrong, please correct me.

Edit: Changed v1.6 to v1.8 since the 1.6 links are no longer available.

How to group dataframe rows into list in pandas groupby

If looking for a unique list while grouping multiple columns this could probably help:

df.groupby('a').agg(lambda x: list(set(x))).reset_index()

How do I close an open port from the terminal on the Mac?

I use lsof combined with kill, as mentioned above; but wrote a quick little bash script to automate this process.

With this script, you can simply type killport 3000 from anywhere, and it will kill all processes running on port 3000.

https://github.com/xtrasimplicity/killport

Why can't Visual Studio find my DLL?

To add to Oleg's answer:

I was able to find the DLL at runtime by appending Visual Studio's $(ExecutablePath) to the PATH environment variable in Configuration Properties->Debugging. This macro is exactly what's defined in the Configuration Properties->VC++ Directories->Executable Directories field*, so if you have that setup to point to any DLLs you need, simply adding this to your PATH makes finding the DLLs at runtime easy!

* I actually don't know if the $(ExecutablePath) macro uses the project's Executable Directories setting or the global Property Pages' Executable Directories setting. Since I have all of my libraries that I often use configured through the Property Pages, these directories show up as defaults for any new projects I create.

How do I get the current mouse screen coordinates in WPF?

Or in pure WPF use PointToScreen.

Sample helper method:

// Gets the absolute mouse position, relative to screen
Point GetMousePos() => _window.PointToScreen(Mouse.GetPosition(_window));

Create a OpenSSL certificate on Windows

If you're on windows and using apache, maybe via WAMP or the Drupal stack installer, you can additionally download the git for windows package, which includes many useful linux command line tools, one of which is openssl.

The following command creates the self signed certificate and key needed for apache and works fine in windows:

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout privatekey.key -out certificate.crt

Angular: 'Cannot find a differ supporting object '[object Object]' of type 'object'. NgFor only supports binding to Iterables such as Arrays'

Remember to pipe Observables to async, like *ngFor item of items$ | async, where you are trying to *ngFor item of items$ where items$ is obviously an Observable because you notated it with the $ similar to items$: Observable<IValuePair>, and your assignment may be something like this.items$ = this.someDataService.someMethod<IValuePair>() which returns an Observable of type T.

Adding to this... I believe I have used notation like *ngFor item of (items$ | async)?.someProperty

Using classes with the Arduino

On this page, the Arduino sketch defines a couple of Structs (plus a couple of methods) which are then called in the setup loop and main loop. Simple enough to interpret, even for a barely-literate programmer like me.

How to test which port MySQL is running on and whether it can be connected to?

Both URLs are incorrect - should be

jdbc:mysql://host:port/database

I thought it went without saying, but connecting to a database with Java requires a JDBC driver. You'll need the MySQL JDBC driver.

Maybe you can connect using a socket over TCP/IP. Check out the MySQL docs.

See http://dev.mysql.com/doc/refman/5.0/en/connector-j-reference-configuration-properties.html

UPDATE:

I tried to telnet into MySQL (telnet ip 3306), but it doesn't work:

http://lists.mysql.com/win32/253

I think this is what you had in mind.

Redirect HTTP to HTTPS on default virtual host without ServerName

I have use mkcert to create infinites *.dev.net subdomains & localhost with valid HTTPS/SSL certs (Windows 10 XAMPP & Linux Debian 10 Apache2)

I create the certs on Windows with mkcert v1.4.0 (execute CMD as Administrator):

mkcert -install
mkcert localhost "*.dev.net"

This create in Windows 10 this files (I will install it first in Windows 10 XAMPP)

localhost+1.pem
localhost+1-key.pem

Overwrite the XAMPP default certs:

copy "localhost+1.pem" C:\xampp\apache\conf\ssl.crt\server.crt
copy "localhost+1-key.pem"  C:\xampp\apache\conf\ssl.key\server.key

Now, in Apache2 for Debian 10, activate SSL & vhost_alias

a2enmod vhosts_alias
a2enmod ssl
a2ensite default-ssl
systemctl restart apache2

For vhost_alias add this Apache2 config:

nano /etc/apache2/sites-available/999-vhosts_alias.conf

With this content:

<VirtualHost *:80>
   UseCanonicalName Off
   ServerAlias *.dev.net
   VirtualDocumentRoot "/var/www/html/%0/"
</VirtualHost>

Add the site:

a2ensite 999-vhosts_alias

Copy the certs to /root/mkcert by SSH and let overwrite the Debian ones:

systemctl stop apache2

mv /etc/ssl/certs/ssl-cert-snakeoil.pem /etc/ssl/certs/ssl-cert-snakeoil.pem.bak
mv /etc/ssl/private/ssl-cert-snakeoil.key /etc/ssl/private/ssl-cert-snakeoil.key.bak

cp "localhost+1.pem" /etc/ssl/certs/ssl-cert-snakeoil.pem
cp "localhost+1-key.pem" /etc/ssl/private/ssl-cert-snakeoil.key

chown root:ssl-cert /etc/ssl/private/ssl-cert-snakeoil.key
chmod 640 /etc/ssl/private/ssl-cert-snakeoil.key

systemctl start apache2

Edit the SSL config

nano /etc/apache2/sites-enabled/default-ssl.conf

At the start edit the file with this content:

<IfModule mod_ssl.c>
    <VirtualHost *:443>

            UseCanonicalName Off
            ServerAlias *.dev.net
            ServerAdmin webmaster@localhost

            # DocumentRoot /var/www/html/
            VirtualDocumentRoot /var/www/html/%0/

...

Last restart:

systemctl restart apache2

NOTE: don´t forget to create the folders for your subdomains in /var/www/html/

/var/www/html/subdomain1.dev.net
/var/www/html/subdomain2.dev.net
/var/www/html/subdomain3.dev.net

What do the result codes in SVN mean?

I want to say something about the "G" status,

G: Changes on the repo were automatically merged into the working copy

I think the above definition is not cleary, it can generate a little confusion, because all files are automatically merged in to working copy, the correct one should be:

U = item (U)pdated to repository version

G = item’s local changes mer(G)ed with repository

C = item’s local changes (C)onflicted with repository

D = item (D)eleted from working copy

A = item (A)dded to working copy

Error parsing yaml file: mapping values are not allowed here

Maybe this will help someone else, but I've seen this error when the RHS of the mapping contains a colon without enclosing quotes, such as:

someKey: another key: Change to make today: work out more

should be

someKey: another key: "Change to make today: work out more"

Undefined behavior and sequence points

In C99(ISO/IEC 9899:TC3) which seems absent from this discussion thus far the following steteents are made regarding order of evaluaiton.

[...]the order of evaluation of subexpressions and the order in which side effects take place are both unspecified. (Section 6.5 pp 67)

The order of evaluation of the operands is unspecified. If an attempt is made to modify the result of an assignment operator or to access it after the next sequence point, the behavior[sic] is undefined.(Section 6.5.16 pp 91)

Java BigDecimal: Round to the nearest whole value

You want

round(new MathContext(0));  // or perhaps another math context with rounding mode HALF_UP

Searching a string in eclipse workspace

Ctrl+ H, Select "File Search", indicate the "file name pattern", for example *.xml or *.java. And then select the scope "Workspace"

jQuery: How to capture the TAB keypress within a Textbox

You can capture an event tab using this JQuery API.

$( "#yourInputTextId" ).keydown(function(evt) {
   if(evt.key === "Tab")
      //call your function
});

Adding hours to JavaScript Date object?

It is probably better to make the addHours method immutable by returning a copy of the Date object rather than mutating its parameter.

Date.prototype.addHours= function(h){
    var copiedDate = new Date(this.getTime());
    copiedDate.setHours(copiedDate.getHours()+h);
    return copiedDate;
}

This way you can chain a bunch of method calls without worrying about state.

How to convert Base64 String to javascript file object like as from file input form?

const url = 'data:image/png;base6....';
fetch(url)
  .then(res => res.blob())
  .then(blob => {
    const file = new File([blob], "File name",{ type: "image/png" })
  })

Base64 String -> Blob -> File.

Class is inaccessible due to its protection level

Hi You need to change the Button properties from private to public. You can change Under Button >> properties >> Design >> Modifiers >> "public" Once change the protection error will gone.

Budi

updating table rows in postgres using subquery

There are many ways to update the rows.

When it comes to UPDATE the rows using subqueries, you can use any of these approaches.

  1. Approach-1 [Using direct table reference]
UPDATE
  <table1>
SET
  customer=<table2>.customer,
  address=<table2>.address,
  partn=<table2>.partn
FROM
  <table2>
WHERE
  <table1>.address_id=<table2>.address_i;

Explanation: table1 is the table which we want to update, table2 is the table, from which we'll get the value to be replaced/updated. We are using FROM clause, to fetch the table2's data. WHERE clause will help to set the proper data mapping.

  1. Approach-2 [Using SubQueries]
UPDATE
  <table1>
SET
  customer=subquery.customer,
  address=subquery.address,
  partn=subquery.partn
FROM
  (
    SELECT
      address_id, customer, address, partn
    FROM  /* big hairy SQL */ ...
  ) AS subquery
WHERE
  dummy.address_id=subquery.address_id;

Explanation: Here we are using subquerie inside the FROM clause, and giving an alias to it. So that it will act like the table.

  1. Approach-3 [Using multiple Joined tables]
UPDATE
  <table1>
SET
  customer=<table2>.customer,
  address=<table2>.address,
  partn=<table2>.partn
FROM
  <table2> as t2
  JOIN <table3> as t3
  ON
    t2.id = t3.id
WHERE
  <table1>.address_id=<table2>.address_i;

Explanation: Sometimes we face the situation in that table join is so important to get proper data for the update. To do so, Postgres allows us to Join multiple tables inside the FROM clause.

  1. Approach-4 [Using WITH statement]

    • 4.1 [Using simple query]
WITH subquery AS (
    SELECT
      address_id,
      customer,
      address,
      partn
    FROM
      <table1>;
)
UPDATE <table-X>
SET customer = subquery.customer,
    address  = subquery.address,
    partn    = subquery.partn
FROM subquery
WHERE <table-X>.address_id = subquery.address_id;
  • 4.2 [Using query with complex JOIN]
WITH subquery AS (
    SELECT address_id, customer, address, partn
    FROM
      <table1> as t1
    JOIN
      <table2> as t2
    ON
      t1.id = t2.id;
    -- You can build as COMPLEX as this query as per your need.
)
UPDATE <table-X>
SET customer = subquery.customer,
    address  = subquery.address,
    partn    = subquery.partn
FROM subquery
WHERE <table-X>.address_id = subquery.address_id;

Explanation: From Postgres 9.1, this(WITH) concept has been introduces. Using that We can make any complex queries and generate desire result. Here we are using this approach to update the table.

I hope, this would be helpful.

Android Drawing Separator/Divider Line in Layout?

Its very simple. Just create a View with the black background color.

<View
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="#000"/>

This will create a horizontal line with background color. You can also add other attributes such as margins, paddings etc just like any other view.

Is there a typical state machine implementation pattern?

Your question is similar to "is there a typical Data Base implementation pattern"? The answer depends upon what do you want to achieve? If you want to implement a larger deterministic state machine you may use a model and a state machine generator. Examples can be viewed at www.StateSoft.org - SM Gallery. Janusz Dobrowolski

How can I bind to the change event of a textarea in jQuery?

2018, without JQUERY

The question is with JQuery, it's just FYI.

JS

let textareaID = document.getElementById('textareaID');
let yourBtnID = document.getElementById('yourBtnID');
textareaID.addEventListener('input', function() {
    yourBtnID.style.display = 'none';
    if (textareaID.value.length) {
        yourBtnID.style.display = 'inline-block';
    }
});

HTML

<textarea id="textareaID"></textarea>
<button id="yourBtnID" style="display: none;">click me</div>

numpy max vs amax vs maximum

For completeness, in Numpy there are four maximum related functions. They fall into two different categories:

  • np.amax/np.max, np.nanmax: for single array order statistics
  • and np.maximum, np.fmax: for element-wise comparison of two arrays

I. For single array order statistics

NaNs propagator np.amax/np.max and its NaN ignorant counterpart np.nanmax.

  • np.max is just an alias of np.amax, so they are considered as one function.

    >>> np.max.__name__
    'amax'
    >>> np.max is np.amax
    True
    
  • np.max propagates NaNs while np.nanmax ignores NaNs.

    >>> np.max([np.nan, 3.14, -1])
    nan
    >>> np.nanmax([np.nan, 3.14, -1])
    3.14
    

II. For element-wise comparison of two arrays

NaNs propagator np.maximum and its NaNs ignorant counterpart np.fmax.

  • Both functions require two arrays as the first two positional args to compare with.

    # x1 and x2 must be the same shape or can be broadcast
    np.maximum(x1, x2, /, ...);
    np.fmax(x1, x2, /, ...)
    
  • np.maximum propagates NaNs while np.fmax ignores NaNs.

    >>> np.maximum([np.nan, 3.14, 0], [np.NINF, np.nan, 2.72])
    array([ nan,  nan, 2.72])
    >>> np.fmax([np.nan, 3.14, 0], [np.NINF, np.nan, 2.72])
    array([-inf, 3.14, 2.72])
    
  • The element-wise functions are np.ufunc(Universal Function), which means they have some special properties that normal Numpy function don't have.

    >>> type(np.maximum)
    <class 'numpy.ufunc'>
    >>> type(np.fmax)
    <class 'numpy.ufunc'>
    >>> #---------------#
    >>> type(np.max)
    <class 'function'>
    >>> type(np.nanmax)
    <class 'function'>
    

And finally, the same rules apply to the four minimum related functions:

  • np.amin/np.min, np.nanmin;
  • and np.minimum, np.fmin.

Can not get a simple bootstrap modal to work

For me the bootstrap modal was showing and disappearing when I clicked the button tag (in the markup the modal is shown and hidden using data attributes alone). In my gulpfile.js I added the bootstrap.js (which had the modal logic) and the modal.js file. So I think after the browser parses and executes both the files, two click event handlers are attached to the particular dom element (one for each of the files), so one shows the modal the other hides the modal. Hope this helps someone.

get the value of DisplayName attribute

Late to the party I know.

I use this:

public static string GetPropertyDisplayName(PropertyInfo pi)
{
  var dp = pi.GetCustomAttributes(typeof(DisplayNameAttribute), true).Cast<DisplayNameAttribute>().SingleOrDefault();
  return dp != null ? dp.DisplayName : pi.Name;
}

Hope this helps.

Create html documentation for C# code

Doxygen or Sandcastle help file builder are the primary tools that will extract XML documentation into HTML (and other forms) of external documentation.

Note that you can combine these documentation exporters with documentation generators - as you've discovered, Resharper has some rudimentary helpers, but there are also much more advanced tools to do this specific task, such as GhostDoc (for C#/VB code with XML documentation) or my addin Atomineer Pro Documentation (for C#, C++/CLI, C++, C, VB, Java, JavaScript, TypeScript, JScript, PHP, Unrealscript code containing XML, Doxygen, JavaDoc or Qt documentation).

Check free disk space for current partition in bash

Yes:

df -k .

for the current directory.

df -k /some/dir

if you want to check a specific directory.

You might also want to check out the stat(1) command if your system has it. You can specify output formats to make it easier for your script to parse. Here's a little example:

$ echo $(($(stat -f --format="%a*%S" .)))

Oracle 10g: Extract data (select) from XML (CLOB Type)

You can achieve with below queries

  1. select extract(xmltype(xml), '//fax/text()').getStringVal() from mytab;

  2. select extractvalue(xmltype(xml), '//fax') from mytab;

How to execute command stored in a variable?

I think you should put

`

(backtick) symbols around your variable.

What is the usefulness of PUT and DELETE HTTP request methods?

Safe Methods : Get Resource/No modification in resource
Idempotent : No change in resource status if requested many times
Unsafe Methods : Create or Update Resource/Modification in resource
Non-Idempotent : Change in resource status if requested many times

According to your requirement :

1) For safe and idempotent operation (Fetch Resource) use --------- GET METHOD
2) For unsafe and non-idempotent operation (Insert Resource) use--------- POST METHOD
3) For unsafe and idempotent operation (Update Resource) use--------- PUT METHOD
3) For unsafe and idempotent operation (Delete Resource) use--------- DELETE METHOD

"message failed to fetch from registry" while trying to install any module

It could be that the npm registry was down at the time or your connection dropped.

Either way you should upgrade node and npm.

I would recommend using nave to manage your node environments.

https://npmjs.org/package/nave

It allows you to easily install versions and quickly jump between them.

A more useful statusline in vim?

Some times less is more, do you really need to know the percentage through the file you are when coding? What about the type of file?

set statusline=%F%m%r%h%w\ 
set statusline+=%{fugitive#statusline()}\    
set statusline+=[%{strlen(&fenc)?&fenc:&enc}]
set statusline+=\ [line\ %l\/%L]          
set statusline+=%{rvm#statusline()}       

statusline

statusline

I also prefer minimal color as not to distract from the code.

Taken from: https://github.com/krisleech/vimfiles

Note: rvm#statusline is Ruby specific and fugitive#statusline is git specific.

Android video streaming example

I was facing the same problem and found a solution to get the code to work.

The code given in the android-Sdk/samples/android-?/ApiDemos works fine. Copy paste each folder in the android project and then in the MediaPlayerDemo_Video.java put the path of the video you want to stream in the path variable. It is left blank in the code.

The following video stream worked for me: http://www.pocketjourney.com/downloads/pj/video/famous.3gp

I know that RTSP protocol is to be used for streaming, but mediaplayer class supports http for streaming as mentioned in the code.

I googled for the format of the video and found that the video if converted to mp4 or 3gp using Quicktime Pro works fine for streaming.

I tested the final apk on android 2.1. The application dosent work on emulators well. Try it on devices.

I hope this helps..

How to add a named sheet at the end of all Excel sheets?


Try switching the order of your code. You must create the worksheet first in order to name it.

Private Sub CreateSheet()
    Dim ws As Worksheet
    Set ws = Sheets.Add(After:=Sheets(Sheets.Count))
    ws.Name = "Tempo"
End Sub

thanks,

gem install: Failed to build gem native extension (can't find header files)

You need following packages instaled:

  • ruby-dev

  • gcc

  • libffi-dev

  • make

Here's the command for debian distro:

 sudo apt install gcc ruby-dev rubygems libgmp-dev libgmp3-dev make 

How do I get current scope dom-element in AngularJS controller?

The better and correct solution is to have a directive. The scope is the same, whether in the controller of the directive or the main controller. Use $element to do DOM operations. The method defined in the directive controller is accessible in the main controller.

Example, finding a child element:

var app = angular.module('myapp', []);
app.directive("testDir", function () {
    function link(scope, element) { 

    }
    return {
        restrict: "AE", 
        link: link, 
        controller:function($scope,$element){
            $scope.name2 = 'this is second name';
            var barGridSection = $element.find('#barGridSection'); //helps to find the child element.
    }
    };
})

app.controller('mainController', function ($scope) {
$scope.name='this is first name'
});

How to remove CocoaPods from a project?

pod deintegrate and pod clean are two designated commands to remove CocoaPod from your project/repo.

Here is the complete set of commands:

$ sudo gem install cocoapods-deintegrate cocoapods-clean
$ pod deintegrate
$ pod cache clean --all
$ rm Podfile

The original solution was found here: https://medium.com/@icanhazedit/remove-uninstall-deintegrate-cocoapods-from-your-xcode-ios-project-c4621cee5e42#.wd00fj2e5

CocoaPod documentation on pod deintegrate: https://guides.cocoapods.org/terminal/commands.html#pod_deintegrate

HTTP requests and JSON parsing in Python

The requests Python module takes care of both retrieving JSON data and decoding it, due to its builtin JSON decoder. Here is an example taken from the module's documentation:

>>> import requests
>>> r = requests.get('https://github.com/timeline.json')
>>> r.json()
[{u'repository': {u'open_issues': 0, u'url': 'https://github.com/...

So there is no use of having to use some separate module for decoding JSON.

Why do you have to link the math library in C?

As ephemient said, the C library libc is linked by default and this library contains the implementations of stdlib.h, stdio.h and several other standard header files. Just to add to it, according to "An Introduction to GCC" the linker command for a basic "Hello World" program in C is as below:

ld -dynamic-linker /lib/ld-linux.so.2 /usr/lib/crt1.o 
/usr/lib/crti.o /usr/libgcc-lib /i686/3.3.1/crtbegin.o
-L/usr/lib/gcc-lib/i686/3.3.1 hello.o -lgcc -lgcc_eh -lc 
-lgcc -lgcc_eh /usr/lib/gcc-lib/i686/3.3.1/crtend.o /usr/lib/crtn.o

Notice the option -lc in the third line that links the C library.

How to find where gem files are installed

You can check it from your command prompt by running gem help commands and then selecting the proper command:

kirti@kirti-Aspire-5733Z:~$  gem help commands
GEM commands are:

    build                  Build a gem from a gemspec
    cert                   Manage RubyGems certificates and signing settings
    check                  Check a gem repository for added or missing files
    cleanup                Clean up old versions of installed gems in the local
                           repository
    contents               Display the contents of the installed gems
    dependency             Show the dependencies of an installed gem
    environment            Display information about the RubyGems environment
    fetch                  Download a gem and place it in the current directory
    generate_index         Generates the index files for a gem server directory
    help                   Provide help on the 'gem' command
    install                Install a gem into the local repository
    list                   Display gems whose name starts with STRING
    lock                   Generate a lockdown list of gems
    mirror                 Mirror all gem files (requires rubygems-mirror)
    outdated               Display all gems that need updates
    owner                  Manage gem owners on RubyGems.org.
    pristine               Restores installed gems to pristine condition from
                           files located in the gem cache
    push                   Push a gem up to RubyGems.org
    query                  Query gem information in local or remote repositories
    rdoc                   Generates RDoc for pre-installed gems
    regenerate_binstubs    Re run generation of executable wrappers for gems.
    search                 Display all gems whose name contains STRING
    server                 Documentation and gem repository HTTP server
    sources                Manage the sources and cache file RubyGems uses to
                           search for gems
    specification          Display gem specification (in yaml)
    stale                  List gems along with access times
    uninstall              Uninstall gems from the local repository
    unpack                 Unpack an installed gem to the current directory
    update                 Update installed gems to the latest version
    which                  Find the location of a library file you can require
    yank                   Remove a specific gem version release from
                           RubyGems.org

For help on a particular command, use 'gem help COMMAND'.

Commands may be abbreviated, so long as they are unambiguous.
e.g. 'gem i rake' is short for 'gem install rake'.
kirti@kirti-Aspire-5733Z:~$ 

Now from the above I can see the command environment is helpful. So I would do:

kirti@kirti-Aspire-5733Z:~$ gem help environment
Usage: gem environment [arg] [options]


  Common Options:
    -h, --help                       Get help on this command
    -V, --[no-]verbose               Set the verbose level of output
    -q, --quiet                      Silence commands
        --config-file FILE           Use this config file instead of default
        --backtrace                  Show stack backtrace on errors
        --debug                      Turn on Ruby debugging


  Arguments:
    packageversion  display the package version
    gemdir          display the path where gems are installed
    gempath         display path used to search for gems
    version         display the gem format version
    remotesources   display the remote gem servers
    platform        display the supported gem platforms
    <omitted>       display everything

  Summary:
    Display information about the RubyGems environment

  Description:
    The RubyGems environment can be controlled through command line arguments,
    gemrc files, environment variables and built-in defaults.

    Command line argument defaults and some RubyGems defaults can be set in a
    ~/.gemrc file for individual users and a /etc/gemrc for all users. These
    files are YAML files with the following YAML keys:

      :sources: A YAML array of remote gem repositories to install gems from
      :verbose: Verbosity of the gem command. false, true, and :really are the
                levels
      :update_sources: Enable/disable automatic updating of repository metadata
      :backtrace: Print backtrace when RubyGems encounters an error
      :gempath: The paths in which to look for gems
      :disable_default_gem_server: Force specification of gem server host on
    push
      <gem_command>: A string containing arguments for the specified gem command

    Example:

      :verbose: false
      install: --no-wrappers
      update: --no-wrappers
      :disable_default_gem_server: true

    RubyGems' default local repository can be overridden with the GEM_PATH and
    GEM_HOME environment variables. GEM_HOME sets the default repository to
    install into. GEM_PATH allows multiple local repositories to be searched for
    gems.

    If you are behind a proxy server, RubyGems uses the HTTP_PROXY,
    HTTP_PROXY_USER and HTTP_PROXY_PASS environment variables to discover the
    proxy server.

    If you would like to push gems to a private gem server the RUBYGEMS_HOST
    environment variable can be set to the URI for that server.

    If you are packaging RubyGems all of RubyGems' defaults are in
    lib/rubygems/defaults.rb.  You may override these in
    lib/rubygems/defaults/operating_system.rb
kirti@kirti-Aspire-5733Z:~$ 

Finally to show you what you asked, I would do:

kirti@kirti-Aspire-5733Z:~$ gem environment gemdir
/home/kirti/.rvm/gems/ruby-2.0.0-p0
kirti@kirti-Aspire-5733Z:~$ gem environment gempath
/home/kirti/.rvm/gems/ruby-2.0.0-p0:/home/kirti/.rvm/gems/ruby-2.0.0-p0@global
kirti@kirti-Aspire-5733Z:~$ 

Git error on git pull (unable to update local ref)

rm .git/refs/remotes/origin/master

It works to me!

Python: import cx_Oracle ImportError: No module named cx_Oracle error is thown

I have just faced the same problem. First, you need to install the appropriate Oracle client for your OS. In my case, to install it on Ubuntu x64 I have followed this instructions https://help.ubuntu.com/community/Oracle%20Instant%20Client#Install_RPMs

Then, you need to install cx_Oracle, a Python module to connect to the Oracle client. Again, assuming you are running Ubuntu in a 64bit machine, you should type in a shell:

wget -c http://prdownloads.sourceforge.net/cx-oracle/cx_Oracle-5.0.4-11g-unicode-py27-1.x86_64.rpm
sudo alien -i cx_Oracle-5.0.4-11g-unicode-py27-1.x86_64.rpm

This will work for Oracle 11g if you have installed Python 2.7.x, but you can download a different cx_Oracle version in http://cx-oracle.sourceforge.net/ To check which Python version do you have, type in a terminal:

python -V

I hope it helps

Can Console.Clear be used to only clear a line instead of whole console?

Description

You can use the Console.SetCursorPosition function to go to a specific line number. Than you can use this function to clear the line

public static void ClearCurrentConsoleLine()
{
    int currentLineCursor = Console.CursorTop;
    Console.SetCursorPosition(0, Console.CursorTop);
    Console.Write(new string(' ', Console.WindowWidth)); 
    Console.SetCursorPosition(0, currentLineCursor);
}

Sample

Console.WriteLine("Test");
Console.SetCursorPosition(0, Console.CursorTop - 1);
ClearCurrentConsoleLine();

More Information

java: ArrayList - how can I check if an index exists?

a simple way to do this:

try {
  list.get( index ); 
} 
catch ( IndexOutOfBoundsException e ) {
  if(list.isEmpty() || index >= list.size()){
    // Adding new item to list.
  }
}

How to make a phone call programmatically?

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

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

Copy Data from a table in one Database to another separate database

INSERT INTO DB1.dbo.TempTable
SELECT * FROM DB2.dbo.TempTable

If we use this query it will return Primary key error.... So better to choose which columns need to be moved, like

INSERT INTO db1.dbo.TempTable // (List of columns here)
SELECT (Same list of columns here)
FROM db2.dbo.TempTable

How to define partitioning of DataFrame?

I was able to do this using RDD. But I don't know if this is an acceptable solution for you. Once you have the DF available as an RDD, you can apply repartitionAndSortWithinPartitions to perform custom repartitioning of data.

Here is a sample I used:

class DatePartitioner(partitions: Int) extends Partitioner {

  override def getPartition(key: Any): Int = {
    val start_time: Long = key.asInstanceOf[Long]
    Objects.hash(Array(start_time)) % partitions
  }

  override def numPartitions: Int = partitions
}

myRDD
  .repartitionAndSortWithinPartitions(new DatePartitioner(24))
  .map { v => v._2 }
  .toDF()
  .write.mode(SaveMode.Overwrite)

How to change dot size in gnuplot

Use the pointtype and pointsize options, e.g.

plot "./points.dat" using 1:2 pt 7 ps 10  

where pt 7 gives you a filled circle and ps 10 is the size.

See: Plotting data.

Stop handler.postDelayed()

  Boolean condition=false;  //Instance variable declaration.

 //-----------------Inside oncreate--------------------------------------------------- 
  start =(Button)findViewById(R.id.id_start);
        start.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                starthandler();

                if(condition=true)
                {
                    condition=false;
                }


            }
        });

        stop=(Button) findViewById(R.id.id_stoplocatingsmartplug);

        stop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                stophandler();

            }
        });


    }

//-----------------Inside oncreate---------------------------------------------------

 public void starthandler()
    {

        handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {


                if(!condition)
                {
                    //Do something after 100ms 


                }

            }
        }, 5000);

    }


    public void stophandler()
    {
        condition=true;
    }

httpd-xampp.conf: How to allow access to an external IP besides localhost?

allow from all will not work along with Require local. Instead, try Require ip xxx.xxx.xxx.xx

For Example:

# New XAMPP security concept
#
<LocationMatch "^/(?i:(?:xampp|security|licenses|phpmyadmin|webalizer|server-status|server-info))">
    Require local
    Require ip 10.0.0.1
    ErrorDocument 403 /error/XAMPP_FORBIDDEN.html.var
</LocationMatch>

Java 8 Iterable.forEach() vs foreach loop

I feel that I need to extend my comment a bit...

About paradigm\style

That's probably the most notable aspect. FP became popular due to what you can get avoiding side-effects. I won't delve deep into what pros\cons you can get from this, since this is not related to the question.

However, I will say that the iteration using Iterable.forEach is inspired by FP and rather result of bringing more FP to Java (ironically, I'd say that there is no much use for forEach in pure FP, since it does nothing except introducing side-effects).

In the end I would say that it is rather a matter of taste\style\paradigm you are currently writing in.

About parallelism.

From performance point of view there is no promised notable benefits from using Iterable.forEach over foreach(...).

According to official docs on Iterable.forEach :

Performs the given action on the contents of the Iterable, in the order elements occur when iterating, until all elements have been processed or the action throws an exception.

... i.e. docs pretty much clear that there will be no implicit parallelism. Adding one would be LSP violation.

Now, there are "parallell collections" that are promised in Java 8, but to work with those you need to me more explicit and put some extra care to use them (see mschenk74's answer for example).

BTW: in this case Stream.forEach will be used, and it doesn't guarantee that actual work will be done in parallell (depends on underlying collection).

UPDATE: might be not that obvious and a little stretched at a glance but there is another facet of style and readability perspective.

First of all - plain old forloops are plain and old. Everybody already knows them.

Second, and more important - you probably want to use Iterable.forEach only with one-liner lambdas. If "body" gets heavier - they tend to be not-that readable. You have 2 options from here - use inner classes (yuck) or use plain old forloop. People often gets annoyed when they see the same things (iteratins over collections) being done various vays/styles in the same codebase, and this seems to be the case.

Again, this might or might not be an issue. Depends on people working on code.

Spring RestTemplate - how to enable full debugging/logging of requests/responses?

The solution given by xenoterracide to use

logging.level.org.apache.http=DEBUG

is good but the problem is that by default Apache HttpComponents is not used.

To use Apache HttpComponents add to your pom.xml

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpasyncclient</artifactId>
</dependency>

and configure RestTemplate with :

RestTemplate restTemplate = new RestTemplate();
restTemplate.setRequestFactory(new HttpComponentsAsyncClientHttpRequestFactory());

HTML Entity Decode

Here's a quick method that doesn't require creating a div, and decodes the "most common" HTML escaped chars:

function decodeHTMLEntities(text) {
    var entities = [
        ['amp', '&'],
        ['apos', '\''],
        ['#x27', '\''],
        ['#x2F', '/'],
        ['#39', '\''],
        ['#47', '/'],
        ['lt', '<'],
        ['gt', '>'],
        ['nbsp', ' '],
        ['quot', '"']
    ];

    for (var i = 0, max = entities.length; i < max; ++i) 
        text = text.replace(new RegExp('&'+entities[i][0]+';', 'g'), entities[i][1]);

    return text;
}

How do I write a "tab" in Python?

This is the code:

f = open(filename, 'w')
f.write("hello\talex")

The \t inside the string is the escape sequence for the horizontal tabulation.

How to set HTML Auto Indent format on Sublime Text 3?

Create a Keybinding

To auto indent on Sublime text 3 with a key bind try going to

Preferences > Key Bindings - users

And adding this code between the square brackets

{"keys": ["alt+shift+f"], "command": "reindent", "args": {"single_line": false}}

it sets shift + alt + f to be your full page auto indent.

Source here

Note: if this doesn't work correctly then you should convert your indentation to tabs. Also comments in your code can push your code to the wrong indentation level and may have to be moved manually.

Round button with text and icon in flutter

The way i usually do it is by embedding a Row inside the Raised button:

class Sendbutton extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return RaisedButton(
          onPressed: () {},
          color: Colors.black,
          textColor: Colors.white,
          child: Row(
            children: <Widget>[
              Text('Send'),
              Icon(Icons.send)
            ],
          ),

        );
      }
    }

How do I indent multiple lines at once in Notepad++?

The problem was with the QuickText plugin. After removing it, indent worked as normal.

Test a string for a substring

if "ABCD" in "xxxxABCDyyyy":
    # whatever

Mapping two integers to one, in a unique and deterministic way

Although Stephan202's answer is the only truly general one, for integers in a bounded range you can do better. For example, if your range is 0..10,000, then you can do:

#define RANGE_MIN 0
#define RANGE_MAX 10000

unsigned int merge(unsigned int x, unsigned int y)
{
    return (x * (RANGE_MAX - RANGE_MIN + 1)) + y;
}

void split(unsigned int v, unsigned int &x, unsigned int &y)
{
    x = RANGE_MIN + (v / (RANGE_MAX - RANGE_MIN + 1));
    y = RANGE_MIN + (v % (RANGE_MAX - RANGE_MIN + 1));
}

Results can fit in a single integer for a range up to the square root of the integer type's cardinality. This packs slightly more efficiently than Stephan202's more general method. It is also considerably simpler to decode; requiring no square roots, for starters :)

AngularJS: ng-model not binding to ng-checked for checkboxes

Can Declare As the in ng-init also getting true

<!doctype html>
<html ng-app="plunker" >
  <head>
    <meta charset="utf-8">
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css">
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular.js"></script>
    <script src="app.js"></script>
  </head>
  <body ng-controller="MainCtrl" ng-init="testModel['item1']= true">
    <label><input type="checkbox" name="test" ng-model="testModel['item1']"  /> Testing</label><br />
    <label><input type="checkbox" name="test" ng-model="testModel['item2']" /> Testing 2</label><br />
    <label><input type="checkbox" name="test" ng-model="testModel['item3']" /> Testing 3</label><br />
    <input type="button" ng-click="submit()" value="Submit" />
  </body>
</html>

And You Can Select the First One and Object Also Shown here true,false,flase

Check if an element has event listener on it. No jQuery

Nowadays (2016) in Chrome Dev Tools console, you can quickly execute this function below to show all event listeners that have been attached to an element.

getEventListeners(document.querySelector('your-element-selector'));

SSRS expression to format two decimal places does not show zeros

If you want it as a string use:

=Format(Fields!CUL1.Value, "F2")

As a number use:

=FormatNumber(Fields!CUL1.Value, 2)

This will ensure it exports out to excel correctly as a number.

Is it possible to use 'else' in a list comprehension?

Yes, else can be used in Python inside a list comprehension with a Conditional Expression ("ternary operator"):

>>> [("A" if b=="e" else "c") for b in "comprehension"]
['c', 'c', 'c', 'c', 'c', 'A', 'c', 'A', 'c', 'c', 'c', 'c', 'c']

Here, the parentheses "()" are just to emphasize the conditional expression, they are not necessarily required (Operator precedence).

Additionaly, several expressions can be nested, resulting in more elses and harder to read code:

>>> ["A" if b=="e" else "d" if True else "x" for b in "comprehension"]
['d', 'd', 'd', 'd', 'd', 'A', 'd', 'A', 'd', 'd', 'd', 'd', 'd']
>>>

On a related note, a comprehension can also contain its own if condition(s) at the end:

>>> ["A" if b=="e" else "c" for b in "comprehension" if False]
[]
>>> ["A" if b=="e" else "c" for b in "comprehension" if "comprehension".index(b)%2]
['c', 'c', 'A', 'A', 'c', 'c']

Conditions? Yes, multiple ifs are possible, and actually multiple fors, too:

>>> [i for i in range(3) for _ in range(3)]
[0, 0, 0, 1, 1, 1, 2, 2, 2]
>>> [i for i in range(3) if i for _ in range(3) if _ if True if True]
[1, 1, 2, 2]

(The single underscore _ is a valid variable name (identifier) in Python, used here just to show it's not actually used. It has a special meaning in interactive mode)

Using this for an additional conditional expression is possible, but of no real use:

>>> [i for i in range(3)]
[0, 1, 2]
>>> [i for i in range(3) if i]
[1, 2]
>>> [i for i in range(3) if (True if i else False)]
[1, 2]

Comprehensions can also be nested to create "multi-dimensional" lists ("arrays"):

>>> [[i for j in range(i)] for i in range(3)]
[[], [1], [2, 2]]

Last but not least, a comprehension is not limited to creating a list, i.e. else and if can also be used the same way in a set comprehension:

>>> {i for i in "set comprehension"}
{'o', 'p', 'm', 'n', 'c', 'r', 'i', 't', 'h', 'e', 's', ' '}

and a dictionary comprehension:

>>> {k:v for k,v in [("key","value"), ("dict","comprehension")]}
{'key': 'value', 'dict': 'comprehension'}

The same syntax is also used for Generator Expressions:

>>> for g in ("a" if b else "c" for b in "generator"):
...     print(g, end="")
...
aaaaaaaaa>>>

which can be used to create a tuple (there is no tuple comprehension).


Further reading:

Ways to iterate over a list in Java

The basic loop is not recommended as you do not know the implementation of the list.

If that was a LinkedList, each call to

list.get(i)

would be iterating over the list, resulting in N^2 time complexity.

Replace one character with another in Bash

Try this

 echo "hello world" | sed 's/ /./g' 

How to convert a Datetime string to a current culture datetime string

public static DateTime ConvertDateTime(string Date)
    {
        DateTime date=new DateTime();                        
        try
        {
            string CurrentPattern = Thread.CurrentThread.CurrentCulture.DateTimeFormat.ShortDatePattern;                
            string[] Split = new string[] {"-","/",@"\","."};
            string[] Patternvalue = CurrentPattern.Split(Split,StringSplitOptions.None);
            string[] DateSplit = Date.Split(Split,StringSplitOptions.None);
            string NewDate = "";
            if (Patternvalue[0].ToLower().Contains("d") == true && Patternvalue[1].ToLower().Contains("m")==true && Patternvalue[2].ToLower().Contains("y")==true)
            {
                NewDate = DateSplit[1] + "/" + DateSplit[0] + "/" + DateSplit[2];
            }
            else if (Patternvalue[0].ToLower().Contains("m") == true && Patternvalue[1].ToLower().Contains("d")==true && Patternvalue[2].ToLower().Contains("y")==true)
            {
                NewDate = DateSplit[0] + "/" + DateSplit[1] + "/" + DateSplit[2];
            }
            else if (Patternvalue[0].ToLower().Contains("y") == true && Patternvalue[1].ToLower().Contains("m")==true && Patternvalue[2].ToLower().Contains("d")==true)
            {
                NewDate = DateSplit[2] + "/" + DateSplit[0] + "/" + DateSplit[1];
            }
            else if (Patternvalue[0].ToLower().Contains("y") == true && Patternvalue[1].ToLower().Contains("d")==true && Patternvalue[2].ToLower().Contains("m")==true)
            {
                NewDate = DateSplit[2] + "/" + DateSplit[1] + "/" + DateSplit[0];
            }
            date = DateTime.Parse(NewDate, Thread.CurrentThread.CurrentCulture);
        }
        catch (Exception ex)
        {

        }
        finally
        {

        }

        return date;

    }

How To Check If A Key in **kwargs Exists?

if kwarg.__len__() != 0:
    print(kwarg)

Resolving IP Address from hostname with PowerShell

You could use vcsjones's solution, but this might cause problems with further ping/tracert commands, since the result is an array of addresses and you need only one.

To select the proper address, Send an ICMP echo request and read the Address property of the echo reply:

$ping = New-Object System.Net.NetworkInformation.Ping
$ip = $($ping.Send("yourhosthere").Address).IPAddressToString

Though the remarks from the documentation say:

The Address returned by any of the Send overloads can originate from a malicious remote computer. Do not connect to the remote computer using this address. Use DNS to determine the IP address of the machine to which you want to connect.

Detect whether a Python string is a number or a letter

Check if string is positive digit (integer) and alphabet

You may use str.isdigit() and str.isalpha() to check whether given string is positive integer and alphabet respectively.

Sample Results:

# For alphabet
>>> 'A'.isdigit()
False
>>> 'A'.isalpha()
True

# For digit
>>> '1'.isdigit()
True
>>> '1'.isalpha()
False

Check for strings as positive/negative - integer/float

str.isdigit() returns False if the string is a negative number or a float number. For example:

# returns `False` for float
>>> '123.3'.isdigit()
False
# returns `False` for negative number
>>> '-123'.isdigit()
False

If you want to also check for the negative integers and float, then you may write a custom function to check for it as:

def is_number(n):
    try:
        float(n)   # Type-casting the string to `float`.
                   # If string is not a valid `float`, 
                   # it'll raise `ValueError` exception
    except ValueError:
        return False
    return True

Sample Run:

>>> is_number('123')    # positive integer number
True

>>> is_number('123.4')  # positive float number
True
 
>>> is_number('-123')   # negative integer number
True

>>> is_number('-123.4') # negative `float` number
True

>>> is_number('abc')    # `False` for "some random" string
False

Discard "NaN" (not a number) strings while checking for number

The above functions will return True for the "NAN" (Not a number) string because for Python it is valid float representing it is not a number. For example:

>>> is_number('NaN')
True

In order to check whether the number is "NaN", you may use math.isnan() as:

>>> import math
>>> nan_num = float('nan')

>>> math.isnan(nan_num)
True

Or if you don't want to import additional library to check this, then you may simply check it via comparing it with itself using ==. Python returns False when nan float is compared with itself. For example:

# `nan_num` variable is taken from above example
>>> nan_num == nan_num
False

Hence, above function is_number can be updated to return False for "NaN" as:

def is_number(n):
    is_number = True
    try:
        num = float(n)
        # check for "nan" floats
        is_number = num == num   # or use `math.isnan(num)`
    except ValueError:
        is_number = False
    return is_number

Sample Run:

>>> is_number('Nan')   # not a number "Nan" string
False

>>> is_number('nan')   # not a number string "nan" with all lower cased
False

>>> is_number('123')   # positive integer
True

>>> is_number('-123')  # negative integer
True

>>> is_number('-1.12') # negative `float`
True

>>> is_number('abc')   # "some random" string
False

Allow Complex Number like "1+2j" to be treated as valid number

The above function will still return you False for the complex numbers. If you want your is_number function to treat complex numbers as valid number, then you need to type cast your passed string to complex() instead of float(). Then your is_number function will look like:

def is_number(n):
    is_number = True
    try:
        #      v type-casting the number here as `complex`, instead of `float`
        num = complex(n)
        is_number = num == num
    except ValueError:
        is_number = False
    return is_number

Sample Run:

>>> is_number('1+2j')    # Valid 
True                     #      : complex number 

>>> is_number('1+ 2j')   # Invalid 
False                    #      : string with space in complex number represetantion
                         #        is treated as invalid complex number

>>> is_number('123')     # Valid
True                     #      : positive integer

>>> is_number('-123')    # Valid 
True                     #      : negative integer

>>> is_number('abc')     # Invalid 
False                    #      : some random string, not a valid number

>>> is_number('nan')     # Invalid
False                    #      : not a number "nan" string

PS: Each operation for each check depending on the type of number comes with additional overhead. Choose the version of is_number function which fits your requirement.

How to make a text box have rounded corners?

You could use CSS to do that, but it wouldn't be supported in IE8-. You can use some site like http://borderradius.com to come up with actual CSS you'd use, which would look something like this (again, depending on how many browsers you're trying to support):

-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;

Python how to plot graph sine wave

import matplotlib.pyplot as plt # For ploting
import numpy as np # to work with numerical data efficiently

fs = 100 # sample rate 
f = 2 # the frequency of the signal

x = np.arange(fs) # the points on the x axis for plotting
# compute the value (amplitude) of the sin wave at the for each sample
y = np.sin(2*np.pi*f * (x/fs)) 

#this instruction can only be used with IPython Notbook. 
% matplotlib inline
# showing the exact location of the smaples
plt.stem(x,y, 'r', )
plt.plot(x,y)

enter image description here

Does Spring Data JPA have any way to count entites using method name resolving?

As of Spring Data 1.7.1.RELEASE you can do it with two different ways,

  1. The new way, using query derivation for both count and delete queries. Read this, (Example 5). Example,
    public interface UserRepository extends CrudRepository<User, Integer> {
        long countByName(String name);
    }
  1. The old way, Using @Query annotation.
    Example,
    public interface UserRepository extends CrudRepository<User, Integer> {
        @Query("SELECT COUNT(u) FROM User u WHERE u.name=?1")
        long aMethodNameOrSomething(String name);
    }

or using @Param annotation also,

public interface UserRepository extends CrudRepository<User, Integer> {
    @Query("SELECT COUNT(u) FROM User u WHERE u.name=:name")
    long aMethodNameOrSomething(@Param("name") String name);
}

Check also this so answer.

HRESULT: 0x800A03EC on Worksheet.range

This could also be caused if you have no room on the partition you are saving to.

I checked my HD and foind it was maxed. Moving some un-needed files to a different partition resolved my problem.

socket.shutdown vs socket.close

Explanation of shutdown and close: Graceful shutdown (msdn)

Shutdown (in your case) indicates to the other end of the connection there is no further intention to read from or write to the socket. Then close frees up any memory associated with the socket.

Omitting shutdown may cause the socket to linger in the OSs stack until the connection has been closed gracefully.

IMO the names 'shutdown' and 'close' are misleading, 'close' and 'destroy' would emphasise their differences.

JPA Native Query select and cast object

Please refer JPA : How to convert a native query result set to POJO class collection

For Postgres 9.4,

List<String> list = em.createNativeQuery("select cast(row_to_json(u) as text) from myschema.USER_ u WHERE ID = ?")
                   .setParameter(1, id).getResultList();

User map = new ObjectMapper().readValue(list.get(0), User.class);

Syntax error: Illegal return statement in JavaScript

where are you trying to return the value? to console in dev tools is better for debugging

<script type = 'text/javascript'>
var ask = confirm('".$message."');
function answer(){
  if(ask==false){
    return false;     
  } else {
    return true;
  }
}
console.log("ask : ", ask);
console.log("answer : ", answer());
</script>

Is it possible to use global variables in Rust?

You can use static variables fairly easily as long as they are thread-local.

The downside is that the object will not be visible to other threads your program might spawn. The upside is that unlike truly global state, it is entirely safe and is not a pain to use - true global state is a massive pain in any language. Here's an example:

extern mod sqlite;

use std::cell::RefCell;

thread_local!(static ODB: RefCell<sqlite::database::Database> = RefCell::new(sqlite::open("test.db"));

fn main() {
    ODB.with(|odb_cell| {
        let odb = odb_cell.borrow_mut();
        // code that uses odb goes here
    });
}

Here we create a thread-local static variable and then use it in a function. Note that it is static and immutable; this means that the address at which it resides is immutable, but thanks to RefCell the value itself will be mutable.

Unlike regular static, in thread-local!(static ...) you can create pretty much arbitrary objects, including those that require heap allocations for initialization such as Vec, HashMap and others.

If you cannot initialize the value right away, e.g. it depends on user input, you may also have to throw Option in there, in which case accessing it gets a bit unwieldy:

extern mod sqlite;

use std::cell::RefCell;

thread_local!(static ODB: RefCell<Option<sqlite::database::Database>> = RefCell::New(None));

fn main() {
    ODB.with(|odb_cell| {
        // assumes the value has already been initialized, panics otherwise
        let odb = odb_cell.borrow_mut().as_mut().unwrap();
        // code that uses odb goes here
    });
}

How do I calculate the MD5 checksum of a file in Python?

In Python 3.8+ you can do

import hashlib

with open("your_filename.png", "rb") as f:
    file_hash = hashlib.md5()
    while chunk := f.read(8192):
        file_hash.update(chunk)

print(file_hash.digest())
print(file_hash.hexdigest())  # to get a printable str instead of bytes

On Python 3.7 and below:

with open("your_filename.png", "rb") as f:
    file_hash = hashlib.md5()
    chunk = f.read(8192)
    while chunk:
        file_hash.update(chunk)
        chunk = f.read(8192)

print(file_hash.hexdigest())

This reads the file 8192 (or 2¹³) bytes at a time instead of all at once with f.read() to use less memory.


Consider using hashlib.blake2b instead of md5 (just replace md5 with blake2b in the above snippets). It's cryptographically secure and faster than MD5.

MongoDB: How To Delete All Records Of A Collection in MongoDB Shell?

db.users.count()
db.users.remove({})
db.users.count()

Error in plot.window(...) : need finite 'xlim' values

The problem is that you're (probably) trying to plot a vector that consists exclusively of missing (NA) values. Here's an example:

> x=rep(NA,100)
> y=rnorm(100)
> plot(x,y)
Error in plot.window(...) : need finite 'xlim' values
In addition: Warning messages:
1: In min(x) : no non-missing arguments to min; returning Inf
2: In max(x) : no non-missing arguments to max; returning -Inf

In your example this means that in your line plot(costs,pseudor2,type="l"), costs is completely NA. You have to figure out why this is, but that's the explanation of your error.


From comments:

Scott C Wilson: Another possible cause of this message (not in this case, but in others) is attempting to use character values as X or Y data. You can use the class function to check your x and Y values to be sure if you think this might be your issue.

stevec: Here is a quick and easy solution to that problem (basically wrap x in as.factor(x))

How can I write a regex which matches non greedy?

The non-greedy ? works perfectly fine. It's just that you need to select dot matches all option in the regex engines (regexpal, the engine you used, also has this option) you are testing with. This is because, regex engines generally don't match line breaks when you use .. You need to tell them explicitly that you want to match line-breaks too with .

For example,

<img\s.*?>

works fine!

Check the results here.

Also, read about how dot behaves in various regex flavours.

git clone through ssh

Disclaimer: This is just a copy of a comment by bobbaluba made more visible for future visitors. It helped me more than any other answer.


You have to drop the ssh:// prefix when using git clone as an example

git clone [email protected]:owner/repo.git

Java get month string from integer

Month enum

You could use the Month enum. This enum is defined as part of the new java.time framework built into Java 8 and later.

int monthNumber = 10;
Month.of(monthNumber).name();

The output would be:

OCTOBER

Localize

Localize to a language beyond English by calling getDisplayName on the same Enum.

String output = Month.OCTOBER.getDisplayName ( TextStyle.FULL , Locale.CANADA_FRENCH );

output:

octobre

What is the significance of load factor in HashMap?

Default initial capacity of the HashMap takes is 16 and load factor is 0.75f (i.e 75% of current map size). The load factor represents at what level the HashMap capacity should be doubled.

For example product of capacity and load factor as 16 * 0.75 = 12. This represents that after storing the 12th key – value pair into the HashMap , its capacity becomes 32.

Is it possible to break a long line to multiple lines in Python?

From PEP 8 - Style Guide for Python Code:

The preferred way of wrapping long lines is by using Python's implied line continuation inside parentheses, brackets and braces. If necessary, you can add an extra pair of parentheses around an expression, but sometimes using a backslash looks better. Make sure to indent the continued line appropriately.

Example of implicit line continuation:

a = some_function(
    '1' + '2' + '3' - '4')

On the topic of line-breaks around a binary operator, it goes on to say:-

For decades the recommended style was to break after binary operators. But this can hurt readability in two ways: the operators tend to get scattered across different columns on the screen, and each operator is moved away from its operand and onto the previous line.

In Python code, it is permissible to break before or after a binary operator, as long as the convention is consistent locally. For new code Knuth's style (line breaks before the operator) is suggested.

Example of explicit line continuation:

a = '1'   \
    + '2' \
    + '3' \
    - '4'

React passing parameter via onclick event using ES6 syntax

Something nobody has mentioned so far is to make handleRemove return a function.

You can do something like:

handleRemove = id => event => {
  // Do stuff with id and event
}

// render...
  return <button onClick={this.handleRemove(id)} />

However all of these solutions have the downside of creating a new function on each render. Better to create a new component for Button which gets passed the id and the handleRemove separately.

Guzzlehttp - How get the body of a response from Guzzle 6?

Guzzle implements PSR-7. That means that it will by default store the body of a message in a Stream that uses PHP temp streams. To retrieve all the data, you can use casting operator:

$contents = (string) $response->getBody();

You can also do it with

$contents = $response->getBody()->getContents();

The difference between the two approaches is that getContents returns the remaining contents, so that a second call returns nothing unless you seek the position of the stream with rewind or seek .

$stream = $response->getBody();
$contents = $stream->getContents(); // returns all the contents
$contents = $stream->getContents(); // empty string
$stream->rewind(); // Seek to the beginning
$contents = $stream->getContents(); // returns all the contents

Instead, usings PHP's string casting operations, it will reads all the data from the stream from the beginning until the end is reached.

$contents = (string) $response->getBody(); // returns all the contents
$contents = (string) $response->getBody(); // returns all the contents

Documentation: http://docs.guzzlephp.org/en/latest/psr7.html#responses

How to get config parameters in Symfony2 Twig Templates

In confing.yml

# app/config/config.yml
twig:
  globals:
    version: '%app.version%'

In Twig view

# twig view
{{ version }}

Cocoa Touch: How To Change UIView's Border Color And Thickness?

If you want to add different border on different sides, may be add a subview with the specific style is a way easy to come up with.

How to split a comma-separated string?

For completeness, using the Guava library, you'd do: Splitter.on(",").split(“dog,cat,fox”)

Another example:

String animals = "dog,cat, bear,elephant , giraffe ,  zebra  ,walrus";
List<String> l = Lists.newArrayList(Splitter.on(",").trimResults().split(animals));
// -> [dog, cat, bear, elephant, giraffe, zebra, walrus]

Splitter.split() returns an Iterable, so if you need a List, wrap it in Lists.newArrayList() as above. Otherwise just go with the Iterable, for example:

for (String animal : Splitter.on(",").trimResults().split(animals)) {
    // ...
}

Note how trimResults() handles all your trimming needs without having to tweak regexes for corner cases, as with String.split().

If your project uses Guava already, this should be your preferred solution. See Splitter documentation in Guava User Guide or the javadocs for more configuration options.

How to URL encode in Python 3?

You’re looking for urllib.parse.urlencode

import urllib.parse

params = {'username': 'administrator', 'password': 'xyz'}
encoded = urllib.parse.urlencode(params)
# Returns: 'username=administrator&password=xyz'

Using Linq select list inside list

After my previous answer disaster, I'm going to try something else.

List<Model> usrList  = 
(list.Where(n => n.application == "applicationame").ToList());
usrList.ForEach(n => n.users.RemoveAll(n => n.surname != "surname"));

How to remove focus from single editText

I've tryed much to clear focus of an edit text. clearfocus() and focusable and other things never worked for me. So I came up with the idea of letting a fake edittext gain focus:

<LinearLayout
    ...
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        ...
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <!--here comes your stuff-->

    </LinearLayout>

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/fake"
        android:textSize="1sp"/>

</LinearLayout>

then in your java code:

View view = Activity.this.getCurrentFocus();
                    if (view != null) {
                        InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
                        imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
                        fake.requestFocus();
                    }

it will hide the keyboard and remove the focus of any edittext that has it. and also as you see the fake edittext is out of screen and can't be seen

I want to vertical-align text in select box

Try to set the "line-height" attribute

Like this:

select{
    height: 28px !important;
    line-height: 28px;
}

Here you are some documentation about this attribute:

http://www.w3.org/wiki/CSS/Properties/line-height

http://www.w3schools.com/cssref/pr_dim_line-height.asp

How to compare two dates in php

you can try something like:

        $date1 = date_create('2014-1-23'); // format of yyyy-mm-dd
        $date2 = date_create('2014-2-3'); // format of yyyy-mm-dd
        $dateDiff = date_diff($date1, $date2);
        var_dump($dateDiff);

You can then access the difference in days like this $dateDiff->d;

Function pointer as a member of a C struct

Maybe I am missing something here, but did you allocate any memory for that PString before you accessed it?

PString * initializeString() {
    PString *str;
    str = (PString *) malloc(sizeof(PString));
    str->length = &length;
    return str;
}

How to create a file in Linux from terminal window?

Depending on what you want the file to contain:

  • touch /path/to/file for an empty file
  • somecommand > /path/to/file for a file containing the output of some command.

      eg: grep --help > randomtext.txt
          echo "This is some text" > randomtext.txt
    
  • nano /path/to/file or vi /path/to/file (or any other editor emacs,gedit etc)
    It either opens the existing one for editing or creates & opens the empty file to enter, if it doesn't exist


Create the file using cat

$ cat > myfile.txt

Now, just type whatever you want in the file:

Hello World!

CTRL-D to save and exit


There are several possible solutions:

Create an empty file

touch file

>file

echo -n > file

printf '' > file

The echo version will work only if your version of echo supports the -n switch to suppress newlines. This is a non-standard addition. The other examples will all work in a POSIX shell.

Create a file containing a newline and nothing else

echo '' > file

printf '\n' > file

This is a valid "text file" because it ends in a newline.

Write text into a file

"$EDITOR" file

echo 'text' > file

cat > file <<END \
text
END

printf 'text\n' > file

These are equivalent. The $EDITOR command assumes that you have an interactive text editor defined in the EDITOR environment variable and that you interactively enter equivalent text. The cat version presumes a literal newline after the \ and after each other line. Other than that these will all work in a POSIX shell.

Of course there are many other methods of writing and creating files, too.

Copying text outside of Vim with set mouse=a enabled

Instead of set mouse=a use set mouse=r in .vimrc

maximum value of int

Here is a macro I use to get the maximum value for signed integers, which is independent of the size of the signed integer type used, and for which gcc -Woverflow won't complain

#define SIGNED_MAX(x) (~(-1 << (sizeof(x) * 8 - 1)))

int a = SIGNED_MAX(a);
long b = SIGNED_MAX(b);
char c = SIGNED_MAX(c); /* if char is signed for this target */
short d = SIGNED_MAX(d);
long long e = SIGNED_MAX(e);

How to pick a new color for each plotted line within a figure in matplotlib?

prop_cycle

color_cycle was deprecated in 1.5 in favor of this generalization: http://matplotlib.org/users/whats_new.html#added-axes-prop-cycle-key-to-rcparams

# cycler is a separate package extracted from matplotlib.
from cycler import cycler
import matplotlib.pyplot as plt

plt.rc('axes', prop_cycle=(cycler('color', ['r', 'g', 'b'])))
plt.plot([1, 2])
plt.plot([2, 3])
plt.plot([3, 4])
plt.plot([4, 5])
plt.plot([5, 6])
plt.show()

Also shown in the (now badly named) example: http://matplotlib.org/1.5.1/examples/color/color_cycle_demo.html mentioned at: https://stackoverflow.com/a/4971431/895245

Tested in matplotlib 1.5.1.

jquery to loop through table rows and cells, where checkob is checked, concatenate

UPDATED

I've updated your demo: http://jsfiddle.net/terryyounghk/QS56z/18/

Also, I've changed two ^= to *=. See http://api.jquery.com/category/selectors/

And note the :checked selector. See http://api.jquery.com/checked-selector/

function createcodes() {

    //run through each row
    $('.authors-list tr').each(function (i, row) {

        // reference all the stuff you need first
        var $row = $(row),
            $family = $row.find('input[name*="family"]'),
            $grade = $row.find('input[name*="grade"]'),
            $checkedBoxes = $row.find('input:checked');

        $checkedBoxes.each(function (i, checkbox) {
            // assuming you layout the elements this way, 
            // we'll take advantage of .next()
            var $checkbox = $(checkbox),
                $line = $checkbox.next(),
                $size = $line.next();

            $line.val(
                $family.val() + ' ' + $size.val() + ', ' + $grade.val()
            );

        });

    });
}

MVC3 DropDownListFor - a simple example?

For binding Dynamic Data in a DropDownList you can do the following:

Create ViewBag in Controller like below

ViewBag.ContribTypeOptions = yourFunctionValue();

now use this value in view like below:

@Html.DropDownListFor(m => m.ContribType, 
    new SelectList(@ViewBag.ContribTypeOptions, "ContribId", 
                   "Value", Model.ContribTypeOptions.First().ContribId), 
    "Select, please")

How to check if a file is empty in Bash?

While the other answers are correct, using the "-s" option will also show the file is empty even if the file does not exist.
By adding this additional check "-f" to see if the file exists first, we ensure the result is correct.

if [ -f diff.txt ]
then
  if [ -s diff.txt ]
  then
    rm -f empty.txt
    touch full.txt
  else
    rm -f full.txt
    touch empty.txt
  fi
else
  echo "File diff.txt does not exist"
fi

Why does Lua have no "continue" statement?

Why is there no continue?

Because it's unnecessary¹. There's very few situations where a dev would need it.

A) When you have a very simple loop, say a 1- or 2-liner, then you can just turn the loop condition around and it's still plenty readable.

B) When you're writing simple procedural code (aka. how we wrote code in the last century), you should also be applying structured programming (aka. how we wrote better code in the last century)

C) If you're writing object-oriented code, your loop body should consist of no more than one or two method calls unless it can be expressed in a one- or two-liner (in which case, see A)

D) If you're writing functional code, just return a plain tail-call for the next iteration.

The only case when you'd want to use a continue keyword is if you want to code Lua like it's python, which it just isn't.²

What workarounds are there for it?

Unless A) applies, in which case there's no need for any workarounds, you should be doing Structured, Object-Oriented or Functional programming. Those are the paradigms that Lua was built for, so you'd be fighting against the language if you go out of your way to avoid their patterns.³


Some clarification:

¹ Lua is a very minimalistic language. It tries to have as few features as it can get away with, and a continue statement isn't an essential feature in that sense.

I think this philosophy of minimalism is captured well by Roberto Ierusalimschy in this 2019 interview:

add that and that and that, put that out, and in the end we understand the final conclusion will not satisfy most people and we will not put all the options everybody wants, so we don’t put anything. In the end, strict mode is a reasonable compromise.

² There seems to be a large ammount of programmers coming to Lua from other languages because whatever program they're trying to script for happens to use it, and many of them want don't seem to want to write anything other than their language of choice, which leads to many questions like "Why doesn't Lua have X feature?"

Matz described a similar situation with Ruby in a recent interview:

The most popular question is: "I’m from the language X community; can’t you introduce a feature from the language X to Ruby?", or something like that. And my usual answer to these requests is… "no, I wouldn’t do that", because we have different language design and different language development policies.

³ There's a few ways to hack your way around this; some users have suggested using goto, which is a good enough aproximation in most cases, but gets very ugly very quickly and breaks completely with nested loops. Using gotos also puts you in danger of having a copy of SICP thrown at you whenever you show your code to anybody else.

How to watch and compile all TypeScript sources?

Technically speaking you have a few options here:

If you are using an IDE like Sublime Text and integrated MSN plugin for Typescript: http://blogs.msdn.com/b/interoperability/archive/2012/10/01/sublime-text-vi-emacs-typescript-enabled.aspx you can create a build system which compile the .ts source to .js automatically. Here is the explanation how you can do it: How to configure a Sublime Build System for TypeScript.

You can define even to compile the source code to destination .js file on file save. There is a sublime package hosted on github: https://github.com/alexnj/SublimeOnSaveBuild which make this happen, only you need to include the ts extension in the SublimeOnSaveBuild.sublime-settings file.

Another possibility would be to compile each file in the command line. You can compile even multiple files at once by separating them with spaces like so: tsc foo.ts bar.ts. Check this thread: How can I pass multiple source files to the TypeScript compiler?, but i think the first option is more handy.

How do I remove  from the beginning of a file?

I had the same problem with the BOM appearing in some of my PHP files ().

If you use PhpStorm you can set at hotkey to remove it in Settings -> IDE Settings -> Keymap -> Main Menu - > File -> Remove BOM.

How to select specific form element in jQuery?

$("#name", '#form2').val("Hello World")

Return from lambda forEach() in java

The return there is returning from the lambda expression rather than from the containing method. Instead of forEach you need to filter the stream:

players.stream().filter(player -> player.getName().contains(name))
       .findFirst().orElse(null);

Here filter restricts the stream to those items that match the predicate, and findFirst then returns an Optional with the first matching entry.

This looks less efficient than the for-loop approach, but in fact findFirst() can short-circuit - it doesn't generate the entire filtered stream and then extract one element from it, rather it filters only as many elements as it needs to in order to find the first matching one. You could also use findAny() instead of findFirst() if you don't necessarily care about getting the first matching player from the (ordered) stream but simply any matching item. This allows for better efficiency when there's parallelism involved.

Typing the Enter/Return key using Python and Selenium

There are the following ways of pressing keys - C#:

Driver.FindElement(By.Id("Value")).SendKeys(Keys.Return);

OR

OpenQA.Selenium.Interactions.Actions action = new OpenQA.Selenium.Interactions.Actions(Driver);
action.SendKeys(OpenQA.Selenium.Keys.Escape);

OR

IWebElement body = GlobalDriver.FindElement(By.TagName("body"));
body.SendKeys(Keys.Escape);

How to trigger a click on a link using jQuery

Well you have to setup the click event first then you can trigger it and see what happens:

//good habits first let's cache our selector
var $myLink = $('#titleee').find('a');
$myLink.click(function (evt) {
  evt.preventDefault();
  alert($(this).attr('href'));
});

// now the manual trigger
$myLink.trigger('click');

C++ passing an array pointer as a function argument

int *a[], when used as a function parameter (but not in normal declarations), is a pointer to a pointer, not a pointer to an array (in normal declarations, it is an array of pointers). A pointer to an array looks like this:

int (*aptr)[N]

Where N is a particular positive integer (not a variable).

If you make your function a template, you can do it and you don't even need to pass the size of the array (because it is automatically deduced):

template<size_t SZ>
void generateArray(int (*aptr)[SZ])
{
    for (size_t i=0; i<SZ; ++i)
        (*aptr)[i] = rand() % 9;
}

int main()
{    
    int a[5];    
    generateArray(&a);
}

You could also take a reference:

template<size_t SZ>
void generateArray(int (&arr)[SZ])
{
    for (size_t i=0; i<SZ; ++i)
        arr[i] = rand() % 9;
}

int main()
{    
    int a[5];    
    generateArray(a);
}

When and why to 'return false' in JavaScript?

I also came to this page after searching "js, when to use 'return false;' Among the other search results was a page I found far more useful and straightforward, on Chris Coyier's CSS-Tricks site: The difference between ‘return false;’ and ‘e.preventDefault();’

The gist of his article is:

function() { return false; }

// IS EQUAL TO

function(e) { e.preventDefault(); e.stopPropagation(); }

though I would still recommend reading the whole article.

Update: After arguing the merits of using return false; as a replacement for e.preventDefault(); & e.stopPropagation(); one of my co-workers pointed out that return false also stops callback execution, as outlined in this article: jQuery Events: Stop (Mis)Using Return False.

The communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for communication

I had the same problem while trying to consume net.tcp wcf service endpoint in a http asmx service.

As I saw no one wrote specific answer WHY is this problem occurring, but only how to be handled properly.

I've been struggling with it several days in a row and finally I found out where the problem comes from in my case.

Initially I thought that when you make a reference to a service the config file will be configured regarding security tag the same way as it's in the source, but that was not the case and I should take care of it manually. In my case I had only

<netTcpBinding>
    <binding name="NetTcpBinding_IAuthenticationLoggerService"
    </binding>
</netTcpBinding>`

Later I saw that the security part is missing and it should looks like this

<netTcpBinding>
    <binding name="NetTcpBinding_IAuthenticationLoggerService" transferMode="Buffered">
      <security mode="None">
        <transport clientCredentialType="None"/>
      </security>
    </binding>
  </netTcpBinding>

The second problem in my case was that I was using transferMode="Streamed" on my source WCF service and in the client I had nothing specific about it, which was bad, because the default transferMode is Buffered and it's important on both places source and client to be configured in the same way.

SQL Query to fetch data from the last 30 days?

The easiest way would be to specify

SELECT productid FROM product where purchase_date > sysdate-30;

Remember this sysdate above has the time component, so it will be purchase orders newer than 03-06-2011 8:54 AM based on the time now.

If you want to remove the time conponent when comparing..

SELECT productid FROM product where purchase_date > trunc(sysdate-30);

And (based on your comments), if you want to specify a particular date, make sure you use to_date and not rely on the default session parameters.

SELECT productid FROM product where purchase_date > to_date('03/06/2011','mm/dd/yyyy')

And regardng the between (sysdate-30) - (sysdate) comment, for orders you should be ok with usin just the sysdate condition unless you can have orders with order_dates in the future.

Scanning Java annotations at runtime

If you're looking for an alternative to reflections I'd like to recommend Panda Utilities - AnnotationsScanner. It's a Guava-free (Guava has ~3MB, Panda Utilities has ~200kb) scanner based on the reflections library source code.

It's also dedicated for future-based searches. If you'd like to scan multiple times included sources or even provide an API, which allows someone scanning current classpath, AnnotationsScannerProcess caches all fetched ClassFiles, so it's really fast.

Simple example of AnnotationsScanner usage:

AnnotationsScanner scanner = AnnotationsScanner.createScanner()
        .includeSources(ExampleApplication.class)
        .build();

AnnotationsScannerProcess process = scanner.createWorker()
        .addDefaultProjectFilters("net.dzikoysk")
        .fetch();

Set<Class<?>> classes = process.createSelector()
        .selectTypesAnnotatedWith(AnnotationTest.class);

Hidden features of Python

Implicit concatenation:

>>> print "Hello " "World"
Hello World

Useful when you want to make a long text fit on several lines in a script:

hello = "Greaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Hello " \
        "Word"

or

hello = ("Greaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Hello " 
         "Word")

Deleting a file in VBA

1.) Check here. Basically do this:

Function FileExists(ByVal FileToTest As String) As Boolean
   FileExists = (Dir(FileToTest) <> "")
End Function

I'll leave it to you to figure out the various error handling needed but these are among the error handling things I'd be considering:

  • Check for an empty string being passed.
  • Check for a string containing characters illegal in a file name/path

2.) How To Delete a File. Look at this. Basically use the Kill command but you need to allow for the possibility of a file being read-only. Here's a function for you:

Sub DeleteFile(ByVal FileToDelete As String)
   If FileExists(FileToDelete) Then 'See above          
      ' First remove readonly attribute, if set
      SetAttr FileToDelete, vbNormal          
      ' Then delete the file
      Kill FileToDelete
   End If
End Sub

Again, I'll leave the error handling to you and again these are the things I'd consider:

  • Should this behave differently for a directory vs. a file? Should a user have to explicitly have to indicate they want to delete a directory?

  • Do you want the code to automatically reset the read-only attribute or should the user be given some sort of indication that the read-only attribute is set?


EDIT: Marking this answer as community wiki so anyone can modify it if need be.

Android ListView not refreshing after notifyDataSetChanged

An answer from AlexGo did the trick for me:

getActivity().runOnUiThread(new Runnable() {
        @Override
        public void run() {
         messages.add(m);
         adapter.notifyDataSetChanged();
         getListView().setSelection(messages.size()-1);
        }
});

List Update worked for me before when the update was triggered from a GUI event, thus being in the UI thread.

However, when I update the list from another event/thread - i.e. a call from outside the app, the update would not be in the UI thread and it ignored the call to getListView. Calling the update with runOnUiThread as above did the trick for me. Thanks!!

Is there a better way to do optional function parameters in JavaScript?

Your logic fails if optionalArg is passed, but evaluates as false - try this as an alternative

if (typeof optionalArg === 'undefined') { optionalArg = 'default'; }

Or an alternative idiom:

optionalArg = (typeof optionalArg === 'undefined') ? 'default' : optionalArg;

Use whichever idiom communicates the intent best to you!

How to push both value and key into PHP array

I was just looking for the same thing and I realized that, once again, my thinking is different because I am old school. I go all the way back to BASIC and PERL and sometimes I forget how easy things really are in PHP.

I just made this function to take all settings from the database where their are 3 columns. setkey, item (key) & value (value) and place them into an array called settings using the same key/value without using push just like above.

Pretty easy & simple really


// Get All Settings
$settings=getGlobalSettings();


// Apply User Theme Choice
$theme_choice = $settings['theme'];

.. etc etc etc ....




function getGlobalSettings(){

    $dbc = mysqli_connect(wds_db_host, wds_db_user, wds_db_pass) or die("MySQL Error: " . mysqli_error());
    mysqli_select_db($dbc, wds_db_name) or die("MySQL Error: " . mysqli_error());
    $MySQL = "SELECT * FROM systemSettings";
    $result = mysqli_query($dbc, $MySQL);
    while($row = mysqli_fetch_array($result)) 
        {
        $settings[$row['item']] = $row['value'];   // NO NEED FOR PUSH
        }
    mysqli_close($dbc);
return $settings;
}


So like the other posts explain... In php there is no need to "PUSH" an array when you are using

Key => Value

AND... There is no need to define the array first either.

$array=array();

Don't need to define or push. Just assign $array[$key] = $value; It is automatically a push and a declaration at the same time.

I must add that for security reasons, (P)oor (H)elpless (P)rotection, I means Programming for Dummies, I mean PHP.... hehehe I suggest that you only use this concept for what I intended. Any other method could be a security risk. There, made my disclaimer!

How to set border on jPanel?

To get fixed padding, I will set layout to java.awt.GridBagLayout with one cell. You can then set padding for each cell. Then you can insert inner JPanel to that cell and (if you need) delegate proper JPanel methods to the inner JPanel.

Eliminating duplicate values based on only one column of the table

I solve such queries using this pattern:

SELECT *
FROM t
WHERE t.field=(
  SELECT MAX(t.field) 
  FROM t AS t0 
  WHERE t.group_column1=t0.group_column1
    AND t.group_column2=t0.group_column2 ...)

That is it will select records where the value of a field is at its max value. To apply it to your query I used the common table expression so that I don't have to repeat the JOIN twice:

WITH site_history AS (
  SELECT sites.siteName, sites.siteIP, history.date
  FROM sites
  JOIN history USING (siteName)
)
SELECT *
FROM site_history h
WHERE date=(
  SELECT MAX(date) 
  FROM site_history h0 
  WHERE h.siteName=h0.siteName)
ORDER BY siteName

It's important to note that it works only if the field we're calculating the maximum for is unique. In your example the date field should be unique for each siteName, that is if the IP can't be changed multiple times per millisecond. In my experience this is commonly the case otherwise you don't know which record is the newest anyway. If the history table has an unique index for (site, date), this query is also very fast, index range scan on the history table scanning just the first item can be used.

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

you can try to install another package:

pip install mysql-connector-python

This package worked fine for me and I got no issues to install.

What's the best way to convert a number to a string in JavaScript?

With number literals, the dot for accessing a property must be distinguished from the decimal dot. This leaves you with the following options if you want to invoke to String() on the number literal 123:

123..toString()
123 .toString() // space before the dot 123.0.toString()
(123).toString()

How to convert hex strings to byte values in Java

Since there was no answer for hex string to single byte conversion, here is mine:

private static byte hexStringToByte(String data) {
    return (byte) ((Character.digit(data.charAt(0), 16) << 4)
                  | Character.digit(data.charAt(1), 16));
}

Sample usage:

hexStringToByte("aa"); // 170
hexStringToByte("ff"); // 255
hexStringToByte("10"); // 16

Or you can also try the Integer.parseInt(String number, int radix) imo, is way better than others.

// first parameter is a number represented in string
// second is the radix or the base number system to be use
Integer.parseInt("de", 16); // 222
Integer.parseInt("ad", 16); // 173
Integer.parseInt("c9", 16); // 201

How to increment a number by 2 in a PHP For Loop

<?php
  for ($n = 0; $n <= 7; $n++) {
    echo '<p>'.($n + 1).'</p>';
    echo '<p>'.($n * 2 + 1).'</p>';
  }
?>

First paragraph:

1, 2, 3, 4, 5, 6, 7, 8

Second paragraph:

1, 3, 5, 7, 9, 11, 13, 15

C++ IDE for Linux?

acme, sam from plan9,

you can use it through Plan 9 from User Space.

Class file has wrong version 52.0, should be 50.0

If you are using javac to compile, and you get this error, then remove all the .class files

rm *.class     # On Unix-based systems

and recompile.

javac fileName.java

Invoke JSF managed bean action on page load

JSF 1.0 / 1.1

Just put the desired logic in the constructor of the request scoped bean associated with the JSF page.

public Bean() {
    // Do your stuff here.
}

JSF 1.2 / 2.x

Use @PostConstruct annotated method on a request or view scoped bean. It will be executed after construction and initialization/setting of all managed properties and injected dependencies.

@PostConstruct
public void init() {
    // Do your stuff here.
}

This is strongly recommended over constructor in case you're using a bean management framework which uses proxies, such as CDI, because the constructor may not be called at the times you'd expect it.

JSF 2.0 / 2.1

Alternatively, use <f:event type="preRenderView"> in case you intend to initialize based on <f:viewParam> too, or when the bean is put in a broader scope than the view scope (which in turn indicates a design problem, but that aside). Otherwise, a @PostConstruct is perfectly fine too.

<f:metadata>
    <f:viewParam name="foo" value="#{bean.foo}" />
    <f:event type="preRenderView" listener="#{bean.onload}" />
</f:metadata>
public void onload() { 
    // Do your stuff here.
}

JSF 2.2+

Alternatively, use <f:viewAction> in case you intend to initialize based on <f:viewParam> too, or when the bean is put in a broader scope than the view scope (which in turn indicates a design problem, but that aside). Otherwise, a @PostConstruct is perfectly fine too.

<f:metadata>
    <f:viewParam name="foo" value="#{bean.foo}" />
    <f:viewAction action="#{bean.onload}" />
</f:metadata>
public void onload() { 
    // Do your stuff here.
}

Note that this can return a String navigation case if necessary. It will be interpreted as a redirect (so you do not need a ?faces-redirect=true here).

public String onload() { 
    // Do your stuff here.
    // ...
    return "some.xhtml";
}

See also:

When should we use Observer and Observable?

They are parts of the Observer design pattern. Usually one or more obervers get informed about changes in one observable. It's a notifcation that "something" happened, where you as a programmer can define what "something" means.

When using this pattern, you decouple the both entities from each another - the observers become pluggable.

How to check existence of user-define table type in SQL Server 2008?

IF EXISTS(SELECT 1 FROM sys.types WHERE name = 'Person' AND is_table_type = 1 AND SCHEMA_ID('VAB') = schema_id)
DROP TYPE VAB.Person;
go
CREATE TYPE VAB.Person AS TABLE
(    PersonID               INT
    ,FirstName              VARCHAR(255)
    ,MiddleName             VARCHAR(255)
    ,LastName               VARCHAR(255)
    ,PreferredName          VARCHAR(255)
);

How to get the innerHTML of selectable jquery element?

Use .val() instead of .innerHTML for getting value of selected option

Use .text() for getting text of selected option

Thanks for correcting :)

Getting multiple keys of specified value of a generic Dictionary?

As a twist of the accepted answer (https://stackoverflow.com/a/255638/986160) assuming that the keys will be associated with signle values in the dictionary. Similar to (https://stackoverflow.com/a/255630/986160) but a bit more elegant. The novelty is in that the consuming class can be used as an enumeration alternative (but for strings too) and that the dictionary implements IEnumerable.

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

namespace MyApp.Dictionaries
{

    class BiDictionary<TFirst, TSecond> : IEnumerable
    {
        IDictionary<TFirst, TSecond> firstToSecond = new Dictionary<TFirst, TSecond>();
        IDictionary<TSecond, TFirst> secondToFirst = new Dictionary<TSecond, TFirst>();

        public void Add(TFirst first, TSecond second)
        {
            firstToSecond.Add(first, second);
            secondToFirst.Add(second, first);
        }

        public TSecond this[TFirst first]
        {
            get { return GetByFirst(first); }
        }

        public TFirst this[TSecond second]
        {
            get { return GetBySecond(second); }
        }

        public TSecond GetByFirst(TFirst first)
        {
            return firstToSecond[first];
        }

        public TFirst GetBySecond(TSecond second)
        {
            return secondToFirst[second];
        }

        public IEnumerator GetEnumerator()
        {
            return GetFirstEnumerator();
        }

        public IEnumerator GetFirstEnumerator()
        {
            return firstToSecond.GetEnumerator();
        }

        public IEnumerator GetSecondEnumerator()
        {
            return secondToFirst.GetEnumerator();
        }
    }
}

And as a consuming class you could have

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

namespace MyApp.Dictionaries
{
    class Greek
    {

        public static readonly string Alpha = "Alpha";
        public static readonly string Beta = "Beta";
        public static readonly string Gamma = "Gamma";
        public static readonly string Delta = "Delta";


        private static readonly BiDictionary<int, string> Dictionary = new BiDictionary<int, string>();


        static Greek() {
            Dictionary.Add(1, Alpha);
            Dictionary.Add(2, Beta);
            Dictionary.Add(3, Gamma);
            Dictionary.Add(4, Delta);
        }

        public static string getById(int id){
            return Dictionary.GetByFirst(id);
        }

        public static int getByValue(string value)
        {
            return Dictionary.GetBySecond(value);
        }

    }
}

Xcode 6 iPhone Simulator Application Support location

To know where your .sqlite file is stored in your AppDelegate.m add the following code

- (NSURL *)applicationDocumentsDirectory
{
    NSLog(@"%@",[[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory      inDomains:NSUserDomainMask] lastObject]);

    return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory     inDomains:NSUserDomainMask] lastObject];
 }

now call this method in AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

  //call here
   [self applicationDocumentsDirectory];

}

python date of the previous month

datetime and the datetime.timedelta classes are your friend.

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

Like this:

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

201202 is printed.

Summarizing count and conditional aggregate functions on the same factor

Assuming that your original dataset is similar to the one you created (i.e. with NA as character. You could specify na.strings while reading the data using read.table. But, I guess NAs would be detected automatically.

The price column is factor which needs to be converted to numeric class. When you use as.numeric, all the non-numeric elements (i.e. "NA", FALSE) gets coerced to NA) with a warning.

library(dplyr)
df %>%
     mutate(price=as.numeric(as.character(price))) %>%  
     group_by(company, year, product) %>%
     summarise(total.count=n(), 
               count=sum(is.na(price)), 
               avg.price=mean(price,na.rm=TRUE),
               max.price=max(price, na.rm=TRUE))

data

I am using the same dataset (except the ... row) that was showed.

df = tbl_df(data.frame(company=c("Acme", "Meca", "Emca", "Acme", "Meca","Emca"),
 year=c("2011", "2010", "2009", "2011", "2010", "2013"), product=c("Wrench", "Hammer",
 "Sonic Screwdriver", "Fairy Dust", "Kindness", "Helping Hand"), price=c("5.67",
 "7.12", "12.99", "10.99", "NA",FALSE)))

Add a common Legend for combined ggplots

Update 2015-Feb

See Steven's answer below


df1 <- read.table(text="group   x     y   
group1 -0.212201  0.358867
group2 -0.279756 -0.126194
group3  0.186860 -0.203273
group4  0.417117 -0.002592
group1 -0.212201  0.358867
group2 -0.279756 -0.126194
group3  0.186860 -0.203273
group4  0.186860 -0.203273",header=TRUE)

df2 <- read.table(text="group   x     y   
group1  0.211826 -0.306214
group2 -0.072626  0.104988
group3 -0.072626  0.104988
group4 -0.072626  0.104988
group1  0.211826 -0.306214
group2 -0.072626  0.104988
group3 -0.072626  0.104988
group4 -0.072626  0.104988",header=TRUE)


library(ggplot2)
library(gridExtra)

p1 <- ggplot(df1, aes(x=x, y=y,colour=group)) + geom_point(position=position_jitter(w=0.04,h=0.02),size=1.8) + theme(legend.position="bottom")

p2 <- ggplot(df2, aes(x=x, y=y,colour=group)) + geom_point(position=position_jitter(w=0.04,h=0.02),size=1.8)

#extract legend
#https://github.com/hadley/ggplot2/wiki/Share-a-legend-between-two-ggplot2-graphs
g_legend<-function(a.gplot){
  tmp <- ggplot_gtable(ggplot_build(a.gplot))
  leg <- which(sapply(tmp$grobs, function(x) x$name) == "guide-box")
  legend <- tmp$grobs[[leg]]
  return(legend)}

mylegend<-g_legend(p1)

p3 <- grid.arrange(arrangeGrob(p1 + theme(legend.position="none"),
                         p2 + theme(legend.position="none"),
                         nrow=1),
             mylegend, nrow=2,heights=c(10, 1))

Here is the resulting plot: 2 plots with common legend