Programs & Examples On #Mysql insert id

Retrieves the ID from the previous INSERT query on this database connection.

How to create an empty file at the command line in Windows?

Reading comments on my post, I have to admit I didn't read the question right.

On the Windows command-line, one way would be to use fsutil:

fsutil file createnew <filename> <size>

An example:

fsutil file createnew myEmptyFile.txt 0

Below is for *nix command-line.

touch filename

This command changes your modified date of a file or creates it if file is not found.

Access camera from a browser

There is a really cool solution from Danny Markov for that. It uses navigator.getUserMedia method and should work in modern browsers. I have tested it successfully with Firefox and Chrome. IE didn't work:

Here is a demo:

Link to Danny Markovs description page:

Link to GitHub:

How do I count unique visitors to my site?


$check_ip = mysql_query("select userip from pageview where page='yourpage'  and userip='$user_ip'");

  $insertview = mysql_query("insert into pageview values('','yourpage','$user_ip')");

  $updateview = mysql_query("update totalview set totalvisit = totalvisit+1 where page='yourpage' ");

code from talkerscode official tutorial if you have any problem

centos: Another MySQL daemon already running with the same unix socket

I just went through this issue and none of the suggestions solved my problem. While I was unable to start MySQL on boot and found the same message in the logs ("Another MySQL daemon already running with the same unix socket"), I was able to start the service once I arrived at the console.

In my configuration file, I found the following line: bind-address=xx.x.x.x. I randomly decided to comment it out, and the error on boot disappeared. Because the bind address provides security, in a way, I decided to explore it further. I was using the machine's IP address, rather than the IPv4 loopback address -

In short, by using as the bind-address, I was able to fix this error. I hope this helps those who have this problem, but are unable to resolve it using the answers detailed above.

Java GC (Allocation Failure)

When use CMS GC in jdk1.8 will appeare this error, i change the G1 Gc solve this problem.

 -Xss512k -Xms6g -Xmx6g -XX:+UseG1GC -XX:MaxGCPauseMillis=200 -XX:InitiatingHeapOccupancyPercent=70 -XX:NewRatio=1 -XX:SurvivorRatio=6 -XX:G1ReservePercent=10 -XX:G1HeapRegionSize=32m -XX:ConcGCThreads=6 -Xloggc:gc.log -XX:+HeapDumpOnOutOfMemoryError -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps 

Use of 'const' for function parameters

Being a VB.NET programmer that needs to use a C++ program with 50+ exposed functions, and a .h file that sporadically uses the const qualifier, it is difficult to know when to access a variable using ByRef or ByVal.

Of course the program tells you by generating an exception error on the line where you made the mistake, but then you need to guess which of the 2-10 parameters is wrong.

So now I have the distasteful task of trying to convince a developer that they should really define their variables (in the .h file) in a manner that allows an automated method of creating all of the VB.NET function definitions easily. They will then smugly say, "read the ... documentation."

I have written an awk script that parses a .h file, and creates all of the Declare Function commands, but without an indicator as to which variables are R/O vs R/W, it only does half the job.


At the encouragement of another user I am adding the following;

Here is an example of a (IMO) poorly formed .h entry;

typedef int (EE_STDCALL *Do_SomethingPtr)( int smfID, const char* cursor_name, const char* sql );

The resultant VB from my script;

    Declare Function Do_Something Lib "SomeOther.DLL" (ByRef smfID As Integer, ByVal cursor_name As String, ByVal sql As String) As Integer

Note the missing "const" on the first parameter. Without it, a program (or another developer) has no Idea the 1st parameter should be passed "ByVal." By adding the "const" it makes the .h file self documenting so that developers using other languages can easily write working code.

Function to clear the console in R and RStudio

In Ubuntu-Gnome, simply pressing CTRL+L should clear the screen.

This also seems to also work well in Windows 10 and 7 and Mac OS X Sierra.

Having both a Created and Last Updated timestamp columns in MySQL 4.0

From the MySQL 5.5 documentation:

One TIMESTAMP column in a table can have the current timestamp as the default value for initializing the column, as the auto-update value, or both. It is not possible to have the current timestamp be the default value for one column and the auto-update value for another column.

Changes in MySQL 5.6.5:

Previously, at most one TIMESTAMP column per table could be automatically initialized or updated to the current date and time. This restriction has been lifted. Any TIMESTAMP column definition can have any combination of DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP clauses. In addition, these clauses now can be used with DATETIME column definitions. For more information, see Automatic Initialization and Updating for TIMESTAMP and DATETIME.


Using DISTINCT will work


REf:- this

Can someone provide an example of a $destroy event for scopes in AngularJS?


Here I have created handle-destroy directive.

ctrl.directive('handleDestroy', function() {
    return function(scope, tElement, attributes) {        
        scope.$on('$destroy', function() {
            alert("In destroy of:" + scope.todo.text);

C# how to change data in DataTable?

dt.Rows[1].ItemArray gives you a copy of item arrays. When you modify it, you're not modifying the original.

You can simply do this:

dt.Rows[1][3] = "Value";

ItemArray property is used when you want to modify all row values.


dt.Rows[1].ItemArray = newItemArray;

How can I run an external command asynchronously from Python?

Considering "I don't have to wait for it to return", one of the easiest solutions will be this:

subprocess.Popen( \
    [path_to_executable, arg1, arg2, ... argN],
    creationflags = subprocess.CREATE_NEW_CONSOLE,

But... From what I read this is not "the proper way to accomplish such a thing" because of security risks created by subprocess.CREATE_NEW_CONSOLE flag.

The key things that happen here is use of subprocess.CREATE_NEW_CONSOLE to create new console and .pid (returns process ID so that you could check program later on if you want to) so that not to wait for program to finish its job.

Difference between using Throwable and Exception in a try catch

Throwable is super class of Exception as well as Error. In normal cases we should always catch sub-classes of Exception, so that the root cause doesn't get lost.

Only special cases where you see possibility of things going wrong which is not in control of your Java code, you should catch Error or Throwable.

I remember catching Throwable to flag that a native library is not loaded.

Dealing with HTTP content in HTTPS pages

Regarding your second requirement - you might be able to utilise the onerror event, ie. <img onerror="some javascript;"...


You could also try iterating through document.images in the dom. There is a complete boolean property which you might be able to use. I don't know for sure whether this will be suitable, but might be worth investigating.

ReactNative: how to center text?

Wherever you have Text component in your page just you need to set style of the Text component.

 <Text style={{ textAlign: 'center' }}> Text here </Text>

you don't need to add any other styling property, this is spectacular magic it will set you text in center of the your UI.

What are the differences between delegates and events?

Delegate is a type-safe function pointer. Event is an implementation of publisher-subscriber design pattern using delegate.

How do I change the language of moment.js?

Whoops slip of the pen. I'd solve this: var moment = function(x) { return moment(x).locale('de'); } The other ways don't really seem to stick/hold under conditions (for me).

How to manually reload Google Map with JavaScript

Yes, you can 'refresh' a Google Map like this:

google.maps.event.trigger(map, 'resize');

This basically sends a signal to your map to redraw it.

Hope that helps!

What is “the inverse side of the association” in a bidirectional JPA OneToMany/ManyToOne association?

The entity which has the table with foreign key in the database is the owning entity and the other table, being pointed at, is the inverse entity.

cc1plus: error: unrecognized command line option "-std=c++11" with g++

you should try this

g++-4.4 -std=c++0x or g++-4.7 -std=c++0x

WCF named pipe minimal example

I just found this excellent little tutorial. broken link (Cached version)

I also followed Microsoft's tutorial which is nice, but I only needed pipes as well.

As you can see, you don't need configuration files and all that messy stuff.

By the way, he uses both HTTP and pipes. Just remove all code lines related to HTTP, and you'll get a pure pipe example.

JPA OneToMany not deleting child

In addition to cletus' answer, JPA 2.0, final since december 2010, introduces an orphanRemoval attribute on @OneToMany annotations. For more details see this blog entry.

Note that since the spec is relatively new, not all JPA 1 provider have a final JPA 2 implementation. For example, the Hibernate 3.5.0-Beta-2 release does not yet support this attribute.

Where is the documentation for the values() method of Enum?

Run this

    for (Method m : sex.class.getDeclaredMethods()) {

you will see

public static test.Sex test.Sex.valueOf(java.lang.String)
public static test.Sex[] test.Sex.values()

These are all public methods that "sex" class has. They are not in the source code, javac.exe added them


  1. never use sex as a class name, it's difficult to read your code, we use Sex in Java

  2. when facing a Java puzzle like this one, I recommend to use a bytecode decompiler tool (I use Andrey Loskutov's bytecode outline Eclispe plugin). This will show all what's inside a class

How to start an application without waiting in a batch file?

I'm making a guess here, but your start invocation probably looks like this:

start "\Foo\Bar\Path with spaces in it\program.exe"

This will open a new console window, using “\Foo\Bar\Path with spaces in it\program.exe” as its title.

If you use start with something that is (or needs to be) surrounded by quotes, you need to put empty quotes as the first argument:

start "" "\Foo\Bar\Path with spaces in it\program.exe"

This is because start interprets the first quoted argument it finds as the window title for a new console window.

How can I delete a service in Windows?

Use services.msc or (Start > Control Panel > Administrative Tools > Services) to find the service in question. Double-click to see the service name and the path to the executable.

Check the exe version information for a clue as to the owner of the service, and use Add/Remove programs to do a clean uninstall if possible.

Failing that, from the command prompt:

sc stop servicexyz
sc delete servicexyz

No restart should be required.

Connect over ssh using a .pem file

chmod 400 mykey.pem

ssh -i mykey.pem [email protected]

Will connect you over ssh using a .pem file to any server.

Changing Placeholder Text Color with Swift

Here am i writing all UIDesignable of UITextField. With the help of this code you can directly access it from UI file Inspector in storyboard

class CustomTextField: UITextField {

@IBInspectable var leftImage: UIImage? {
    didSet {

@IBInspectable var leftPadding: CGFloat = 0 {
    didSet {

@IBInspectable var rightImage: UIImage? {
    didSet {

@IBInspectable var rightPadding: CGFloat = 0 {
    didSet {

private var _isRightViewVisible: Bool = true
var isRightViewVisible: Bool {
    get {
        return _isRightViewVisible
    set {
        _isRightViewVisible = newValue

func updateView() {

    // Placeholder text color
    attributedPlaceholder = NSAttributedString(string: placeholder != nil ?  placeholder! : "", attributes:[NSAttributedString.Key.foregroundColor: tintColor])

func setLeftImage() {
    leftViewMode = UITextField.ViewMode.always
    var view: UIView

    if let image = leftImage {
        let imageView = UIImageView(frame: CGRect(x: leftPadding, y: 0, width: 20, height: 20))
        imageView.image = image
        // Note: In order for your image to use the tint color, you have to select the image in the Assets.xcassets and change the "Render As" property to "Template Image".
        imageView.tintColor = tintColor

        var width = imageView.frame.width + leftPadding

        if borderStyle == UITextField.BorderStyle.none || borderStyle == UITextField.BorderStyle.line {
            width += 5

        view = UIView(frame: CGRect(x: 0, y: 0, width: width, height: 20))
    } else {
        view = UIView(frame: CGRect(x: 0, y: 0, width: leftPadding, height: 20))

    leftView = view

func setRightImage() {
    rightViewMode = UITextField.ViewMode.always

    var view: UIView

    if let image = rightImage, isRightViewVisible {
        let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 20, height: 20))
        imageView.image = image
        // Note: In order for your image to use the tint color, you have to select the image in the Assets.xcassets and change the "Render As" property to "Template Image".
        imageView.tintColor = tintColor

        var width = imageView.frame.width + rightPadding

        if borderStyle == UITextField.BorderStyle.none || borderStyle == UITextField.BorderStyle.line {
            width += 5

        view = UIView(frame: CGRect(x: 0, y: 0, width: width, height: 20))

    } else {
        view = UIView(frame: CGRect(x: 0, y: 0, width: rightPadding, height: 20))

    rightView = view

@IBInspectable public var borderColor: UIColor = UIColor.clear {
    didSet {
        layer.borderColor = borderColor.cgColor

@IBInspectable public var borderWidth: CGFloat = 0 {
    didSet {
        layer.borderWidth = borderWidth

@IBInspectable public var cornerRadius: CGFloat = 0 {
    didSet {
        layer.cornerRadius = cornerRadius
@IBInspectable public var bottomBorder: CGFloat = 0 {
    didSet {
       borderStyle = .none
        layer.backgroundColor = UIColor.white.cgColor

        layer.masksToBounds = false
     //   layer.shadowColor = UIColor.gray.cgColor
        layer.shadowOffset = CGSize(width: 0.0, height: 1.0)
        layer.shadowOpacity = 1.0
        layer.shadowRadius = 0.0
@IBInspectable public var bottomBorderColor : UIColor = UIColor.clear {
    didSet {

        layer.shadowColor = bottomBorderColor.cgColor
        layer.shadowOffset = CGSize(width: 0.0, height: 1.0)
        layer.shadowOpacity = 1.0
        layer.shadowRadius = 0.0
/// Sets the placeholder color
@IBInspectable var placeHolderColor: UIColor? {
    get {
        return self.placeHolderColor
    set {
        self.attributedPlaceholder = NSAttributedString(string:self.placeholder != nil ? self.placeholder! : "", attributes:[NSAttributedString.Key.foregroundColor: newValue!])


Mapping a JDBC ResultSet to an object

No need of storing resultSet values into String and again setting into POJO class. Instead set at the time you are retrieving.

Or best way switch to ORM tools like hibernate instead of JDBC which maps your POJO object direct to database.

But as of now use this:

List<User> users=new ArrayList<User>();

while( {
   User user = new User();      


Using a different font with twitter bootstrap

First of all you have to include your font in your website (or your CSS, to be more specific) using an appropriate @font-face rule.
From here on there are multiple ways to proceed. One thing I would not do is to edit the bootstrap.css directly - since once you get a newer version your changes will be lost. You do however have the possibility to customize your bootstrap files (there's a customize page on their website). Just enter the name of your font with all the fallback names into the corresponding typography textbox. Of course you will have to do this whenever you get a new or updated version of your bootstrap files.
Another chance you have is to overwrite the bootstrap rules within a different stylesheet. If you do this you just have to use selectors that are as specific as (or more specific than) the bootstrap selectors.
Side note: If you care about browser support a single EOT version of your font might not be sufficient. See for a support table.

How to size an Android view based on its parent's dimensions

When you define a layout and view on XML, you can specify the layout width and height of a view to either be wrap content, or fill parent. Taking up half of the area is a bit harder, but if you had something you wanted on the other half you could do something like the following.

   <LinearLayout android:layout_width="fill_parent"
        <ImageView android:layout_height="fill_parent"
        <ImageView android:layout_height="fill_parent"

Giving two things the same weight means that they will stretch to take up the same proportion of the screen. For more info on layouts, see the dev docs.

How do I read and parse an XML file in C#?

You can either:

Examples are on the msdn pages provided

git clone error: RPC failed; curl 56 OpenSSL SSL_read: SSL_ERROR_SYSCALL, errno 10054

I had the exact same problem while trying to setup a Gitlab pipeline executed by a Docker runner installed on a Raspberry Pi 4

Using nload to follow bandwidth usage within Docker runner container while pipeline was cloning the repo i saw the network usage dropped down to a few bytes per seconds..

After a some deeper investigations i figured out that the Raspberry temperature was too high and the network card start to dysfunction above 50° Celsius.

Adding a fan to my Raspberry solved the issue.

How do I clear the previous text field value after submitting the form with out refreshing the entire page?

I believe it's better to use


instead of


incase you have checkboxes in your form use this to rest it:


How to fix 'Microsoft Excel cannot open or save any more documents'

If none of the above worked, try these as well:

  • In Component services >Computes >My Computer>Dcom config>Microsoft Excel Application>Properties, go to security tab, click on customize on all three sections and add the user that want to run the application, and give full permissions to the user.

  • Go to C:\Windows\Temp make sure it exists and it doesn't prompt you for entering.

SSIS Excel Connection Manager failed to Connect to the Source

I found that my excel file that was created in Excel 365 was incompatible with any of the versions available. I re-saved the excel file in 97-2003 version and of course chose that version in the dropdown list and it read the file OK.

What's the difference between "super()" and "super(props)" in React when using es6 classes?

super() is used to call the parent constructor.

super(props) would pass props to the parent constructor.

From your example, super(props) would call the React.Component constructor passing in props as the argument.

More information on super:

How can I create directory tree in C++/Linux?

Here is my example of code (it works for both Windows and Linux):

#include <iostream>
#include <string>
#include <sys/stat.h> // stat
#include <errno.h>    // errno, ENOENT, EEXIST
#if defined(_WIN32)
#include <direct.h>   // _mkdir

bool isDirExist(const std::string& path)
#if defined(_WIN32)
    struct _stat info;
    if (_stat(path.c_str(), &info) != 0)
        return false;
    return (info.st_mode & _S_IFDIR) != 0;
    struct stat info;
    if (stat(path.c_str(), &info) != 0)
        return false;
    return (info.st_mode & S_IFDIR) != 0;

bool makePath(const std::string& path)
#if defined(_WIN32)
    int ret = _mkdir(path.c_str());
    mode_t mode = 0755;
    int ret = mkdir(path.c_str(), mode);
    if (ret == 0)
        return true;

    switch (errno)
    case ENOENT:
        // parent didn't exist, try to create it
            int pos = path.find_last_of('/');
            if (pos == std::string::npos)
#if defined(_WIN32)
                pos = path.find_last_of('\\');
            if (pos == std::string::npos)
                return false;
            if (!makePath( path.substr(0, pos) ))
                return false;
        // now, try to create again
#if defined(_WIN32)
        return 0 == _mkdir(path.c_str());
        return 0 == mkdir(path.c_str(), mode);

    case EEXIST:
        // done!
        return isDirExist(path);

        return false;

int main(int argc, char* ARGV[])
    for (int i=1; i<argc; i++)
        std::cout << "creating " << ARGV[i] << " ... " << (makePath(ARGV[i]) ? "OK" : "failed") << std::endl;
    return 0;


$ makePath 1/2 folderA/folderB/folderC
creating 1/2 ... OK
creating folderA/folderB/folderC ... OK

Using 'make' on OS X

You will have to install the "Developer Tools" that are provided as optional packages in OS X installation disks.

$(document).on("click"... not working?

This works:

<div id="start-element">Click Me</div>

$(document).on("click","#test-element",function() {

$(document).on("click","#start-element",function() {
    $(this).attr("id", "test-element");

Here is the Fiddle

Concatenating multiple text files into a single file in Bash

When you run into a problem where it cats all.txt into all.txt, You can try check all.txt is existing or not, if exists, remove

Like this:

[ -e $"all.txt" ] && rm $"all.txt"

What does Maven do, in theory and in practice? When is it worth to use it?

What it does

Maven is a "build management tool", it is for defining how your .java files get compiled to .class, packaged into .jar (or .war or .ear) files, (pre/post)processed with tools, managing your CLASSPATH, and all others sorts of tasks that are required to build your project. It is similar to Apache Ant or Gradle or Makefiles in C/C++, but it attempts to be completely self-contained in it that you shouldn't need any additional tools or scripts by incorporating other common tasks like downloading & installing necessary libraries etc.

It is also designed around the "build portability" theme, so that you don't get issues as having the same code with the same buildscript working on one computer but not on another one (this is a known issue, we have VMs of Windows 98 machines since we couldn't get some of our Delphi applications compiling anywhere else). Because of this, it is also the best way to work on a project between people who use different IDEs since IDE-generated Ant scripts are hard to import into other IDEs, but all IDEs nowadays understand and support Maven (IntelliJ, Eclipse, and NetBeans). Even if you don't end up liking Maven, it ends up being the point of reference for all other modern builds tools.

Why you should use it

There are three things about Maven that are very nice.

  1. Maven will (after you declare which ones you are using) download all the libraries that you use and the libraries that they use for you automatically. This is very nice, and makes dealing with lots of libraries ridiculously easy. This lets you avoid "dependency hell". It is similar to Apache Ant's Ivy.

  2. It uses "Convention over Configuration" so that by default you don't need to define the tasks you want to do. You don't need to write a "compile", "test", "package", or "clean" step like you would have to do in Ant or a Makefile. Just put the files in the places in which Maven expects them and it should work off of the bat.

  3. Maven also has lots of nice plug-ins that you can install that will handle many routine tasks from generating Java classes from an XSD schema using JAXB to measuring test coverage with Cobertura. Just add them to your pom.xml and they will integrate with everything else you want to do.

The initial learning curve is steep, but (nearly) every professional Java developer uses Maven or wishes they did. You should use Maven on every project although don't be surprised if it takes you a while to get used to it and that sometimes you wish you could just do things manually, since learning something new sometimes hurts. However, once you truly get used to Maven you will find that build management takes almost no time at all.

How to Start

The best place to start is "Maven in 5 Minutes". It will get you start with a project ready for you to code in with all the necessary files and folders set-up (yes, I recommend using the quickstart archetype, at least at first).

After you get started you'll want a better understanding over how the tool is intended to be used. For that "Better Builds with Maven" is the most thorough place to understand the guts of how it works, however, "Maven: The Complete Reference" is more up-to-date. Read the first one for understanding, but then use the second one for reference.

how to remove css property using javascript?

This should do the trick - setting the inline style to normal for zoom:

$('div').attr("style", "zoom:normal;");

android - how to convert int to string and place it in a EditText?

Use +, the string concatenation operator:

ed = (EditText) findViewById (;
int x = 10;

or use String.valueOf(int):


or use Integer.toString(int):


The term 'Get-ADUser' is not recognized as the name of a cmdlet

For the particular case of Windows 10 October 2018 Update or later activedirectory module is not available unless the optional feature RSAT: Active Directory Domain Services and Lightweight Directory Services Tools is installed (instructions here + uncollapse install instructions).

Reopen Windows Powershell and import-module activedirectory will work as expected.

How do you automatically resize columns in a DataGridView control AND allow the user to resize the columns on that same grid?

Slightly neater C# code from Miroslav Zadravec's code assuming all columns are to be autosized

for (int i = 0; i < dgvProblems.Columns.Count; i++)
    dgvProblems.Columns[i].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells;
    int colw = dgvProblems.Columns[i].Width;
    dgvProblems.Columns[i].AutoSizeMode = DataGridViewAutoSizeColumnMode.None;
    dgvProblems.Columns[i].Width = colw;

how to display none through code behind

try this

<div id="login_div" runat="server">

and on the code behind.

login_div.Style.Add("display", "none");

How to completely hide the navigation bar in iPhone / HTML5

Remy Sharp has a good description of the process in his article "Doing it right: skipping the iPhone url bar":

Making the iPhone hide the url bar is fairly simple, you need run the following JavaScript:

window.scrollTo(0, 1); 

However there's the question of when? You have to do this once the height is correct so that the iPhone can scroll to the first pixel of the document, otherwise it will try, then the height will load forcing the url bar back in to view.

You could wait until the images have loaded and the window.onload event fires, but this doesn't always work, if everything is cached, the event fires too early and the scrollTo never has a chance to jump. Here's an example using window.onload:

I personally use a timer for 1 second - which is enough time on a mobile device while you wait to render, but long enough that it doesn't fire too early:

setTimeout(function () {   window.scrollTo(0, 1); }, 1000);

However, you only want this to setup if it's an iPhone (or just mobile) browser, so a sneaky sniff (I don't generally encourage this, but I'm comfortable with this to prevent "normal" desktop browsers from jumping one pixel):

/mobile/i.test(navigator.userAgent) && setTimeout(function
() {   window.scrollTo(0, 1); }, 1000); 

The very last part of this, and this is the part that seems to be missing from some examples I've seen around the web is this: if the user specifically linked to a url fragment, i.e. the url has a hash on it, you don't want to jump. So if I navigate to - I want the browser to scroll naturally to the element whose id is dayconf, and not jump to the top using scrollTo(0, 1):

/mobile/i.test(navigator.userAgent) && !location.hash &&
setTimeout(function () {   window.scrollTo(0, 1); }, 1000);?

Try this out on an iPhone (or simulator) and you'll see it will only scroll when you've landed on the page without a url fragment.

How can I disable mod_security in .htaccess file?

With some web hosts including NameCheap, it's not possible to disable ModSecurity using .htaccess. The only option is to contact tech support and ask them to alter the configuration for you.

How to Use slideDown (or show) function on a table row?

You could try wrapping the contents of the row in a <span> and having your selector be $('#detailed_edit_row span'); - a bit hackish, but I just tested it and it works. I also tried the table-row suggestion above and it didn't seem to work.

update: I've been playing around with this problem, and from all indications jQuery needs the object it performs slideDown on to be a block element. So, no dice. I was able to conjure up a table where I used slideDown on a cell and it didn't affect the layout at all, so I am not sure how yours is set up. I think your only solution is to refactor the table in such a way that it's ok with that cell being a block, or just .show(); the damn thing. Good luck.

Reading a text file with SQL Server

BULK INSERT dbo.temp 

FROM 'c:\temp\file.txt' --- path file in db server 



it work for me but save as by editplus to ansi encoding for multilanguage

How to Auto-start an Android Application?

If by autostart you mean auto start on phone bootup then you should register a BroadcastReceiver for the BOOT_COMPLETED Intent. Android systems broadcasts that intent once boot is completed.

Once you receive that intent you can launch a Service that can do whatever you want to do.

Keep note though that having a Service running all the time on the phone is generally a bad idea as it eats up system resources even when it is idle. You should launch your Service / application only when needed and then stop it when not required.

How to use passive FTP mode in Windows command prompt?

If you are using Windows 10, install Windows Subsystem for Linux, WSL and Ubuntu.

$ ftp
Connected to
230 Logged in successfully
Remote system type is MSDOS.
ftp> passive
Passive mode on.
ftp> passive
Passive mode off.

Intersect Two Lists in C#

You need to first transform data1, in your case by calling ToString() on each element.

Use this if you want to return strings.

List<int> data1 = new List<int> {1,2,3,4,5};
List<string> data2 = new List<string>{"6","3"};

var newData = data1.Select(i => i.ToString()).Intersect(data2);

Use this if you want to return integers.

List<int> data1 = new List<int> {1,2,3,4,5};
List<string> data2 = new List<string>{"6","3"};

var newData = data1.Intersect(data2.Select(s => int.Parse(s));

Note that this will throw an exception if not all strings are numbers. So you could do the following first to check:

int temp;
if(data2.All(s => int.TryParse(s, out temp)))
    // All data2 strings are int's

Table is marked as crashed and should be repaired

Here is where the repair button is:

alt text

ViewPager PagerAdapter not updating the View

Instead of returning POSITION_NONE and creating all fragments again, you can do as I suggested here: Update ViewPager dynamically?

How to send email to multiple recipients with addresses stored in Excel?

You have to loop through every cell in the range "D3:D6" and construct your To string. Simply assigning it to a variant will not solve the purpose. EmailTo becomes an array if you assign the range directly to it. You can do this as well but then you will have to loop through the array to create your To string

Is this what you are trying? (TRIED AND TESTED)

Option Explicit

Sub Mail_workbook_Outlook_1()
     'Working in 2000-2010
     'This example send the last saved version of the Activeworkbook
    Dim OutApp As Object
    Dim OutMail As Object
    Dim emailRng As Range, cl As Range
    Dim sTo As String

    Set emailRng = Worksheets("Selections").Range("D3:D6")

    For Each cl In emailRng 
        sTo = sTo & ";" & cl.Value

    sTo = Mid(sTo, 2)

    Set OutApp = CreateObject("Outlook.Application")
    Set OutMail = OutApp.CreateItem(0)

    On Error Resume Next
    With OutMail
        .To = sTo
        .CC = "[email protected];[email protected]"
        .BCC = ""
        .Subject = "RMA #" & Worksheets("RMA").Range("E1")
        .Body = "Attached to this email is RMA #" & _
        Worksheets("RMA").Range("E1") & _
        ". Please follow the instructions for your department included in this form."
        .Attachments.Add ActiveWorkbook.FullName
         'You can add other files also like this
         '.Attachments.Add ("C:\test.txt")

    End With
    On Error GoTo 0

    Set OutMail = Nothing
    Set OutApp = Nothing
End Sub

How to get current time and date in Android

Here is some few way to get Time and Date

public static void getCurrentTimeUsingDate() {
    Date date = new Date();
    String strDateFormat = "hh:mm:ss a";
    DateFormat dateFormat = new SimpleDateFormat(strDateFormat);
    String formattedDate= dateFormat.format(date);       
    Toast.makeText(this, formattedDate, Toast.LENGTH_SHORT).show();

Time using Calender

public static void getCurrentTimeUsingCalendar() {
    Calendar cal = Calendar.getInstance();
    Date date=cal.getTime();
    DateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
    String formattedDate=dateFormat.format(date);
    Toast.makeText(this, formattedDate, Toast.LENGTH_SHORT).show();

Local time and date

public static void getCurrentTime(){
    System.out.println("-----Current time of your time zone-----");
    LocalTime time =;
    Toast.makeText(this, time, Toast.LENGTH_SHORT).show();

Zone wise Time

public static void getCurrentTimeWithTimeZone(){
    Toast.makeText(this, "Current time of a different time zone using LocalTime", Toast.LENGTH_SHORT).show();

    ZoneId zoneId = ZoneId.of("America/Los_Angeles");
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss");
    String formattedTime=localTime.format(formatter);
    Toast.makeText(this,formattedTime , Toast.LENGTH_SHORT).show();

Easy way to get current time and date

import java.util.Calendar

Date currentTime = Calendar.getInstance().getTime();

How to convert Django Model object to dict with its fields and values?


The newer aggregated answer posted by @zags is more complete and elegant than my own. Please refer to that answer instead.


If you are willing to define your own to_dict method like @karthiker suggested, then that just boils this problem down to a sets problem.

>>># Returns a set of all keys excluding editable = False keys
>>>dict = model_to_dict(instance)

{u'id': 1L, 'reference1': 1L, 'reference2': [1L], 'value': 1}

>>># Returns a set of editable = False keys, misnamed foreign keys, and normal keys
>>>otherDict = SomeModel.objects.filter([0]

{'created': datetime.datetime(2014, 2, 21, 4, 38, 51, tzinfo=<UTC>),
 u'id': 1L,
 'reference1_id': 1L,
 'value': 1L,
 'value2': 2L}

We need to remove the mislabeled foreign keys from otherDict.

To do this, we can use a loop that makes a new dictionary that has every item except those with underscores in them. Or, to save time, we can just add those to the original dict since dictionaries are just sets under the hood.

>>>for item in otherDict.items():
...    if "_" not in item[0]:
...            dict.update({item[0]:item[1]})

Thus we are left with the following dict:

{'created': datetime.datetime(2014, 2, 21, 4, 38, 51, tzinfo=<UTC>),
 u'id': 1L,
 'reference1': 1L,
 'reference2': [1L],
 'value': 1,
 'value2': 2L}

And you just return that.

On the downside, you can't use underscores in your editable=false field names. On the upside, this will work for any set of fields where the user-made fields do not contain underscores.

This is not the best way of doing this, but it could work as a temporary solution until a more direct method is found.

For the example below, dict would be formed based on model_to_dict and otherDict would be formed by filter's values method. I would have done this with the models themselves, but I can't get my machine to accept otherModel.

>>> import datetime
>>> dict = {u'id': 1, 'reference1': 1, 'reference2': [1], 'value': 1}
>>> otherDict = {'created': datetime.datetime(2014, 2, 21, 4, 38, 51), u'id': 1, 'reference1_id': 1, 'value': 1, 'value2': 2}
>>> for item in otherDict.items():
...     if "_" not in item[0]:
...             dict.update({item[0]:item[1]})
>>> dict
{'reference1': 1, 'created': datetime.datetime(2014, 2, 21, 4, 38, 51), 'value2': 2, 'value': 1, 'id': 1, 'reference2': [1]}

That should put you in a rough ballpark of the answer to your question, I hope.

How is TeamViewer so fast?

It sounds indeed like video streaming more than image streaming, as someone suggested. JPEG/PNG compression isn't targeted for these types of speeds, so forget them.

Imagine having a recording codec on your system that can realtime record an incoming video stream (your screen). A bit like Fraps perhaps. Then imagine a video playback codec on the other side (the remote client). As HD recorders can do it (record live and even playback live from the same HD), so should you, in the end. The HD surely can't deliver images quicker than you can read your display, so that isn't the bottleneck. The bottleneck are the video codecs. You'll find the encoder much more of a problem than the decoder, as all decoders are mostly free.

I'm not saying it's simple; I myself have used DirectShow to encode a video file, and it's not realtime by far. But given the right codec I'm convinced it can work.

How to align a <div> to the middle (horizontally/width) of the page

    <div style=" display: table; margin: 250 auto;">
        In center

If you want to change the vertical position, change the value of 250 and you can arrange the content as per your need. There is no need to give the width and other parameters.

websocket.send() parameter

As I understand it, you want the server be able to send messages through from client 1 to client 2. You cannot directly connect two clients because one of the two ends of a WebSocket connection needs to be a server.

This is some pseudocodish JavaScript:


var websocket = new WebSocket("server address");

websocket.onmessage = function(str) {
  console.log("Someone sent: ", str);

// Tell the server this is client 1 (swap for client 2 of course)
  id: "client1"

// Tell the server we want to send something to the other client
  to: "client2",
  data: "foo"


var clients = {};

server.on("data", function(client, str) {
  var obj = JSON.parse(str);

  if("id" in obj) {
    // New client, add it to the id/client object
    clients[] = client;
  } else {
    // Send data to the client requested

Jquery mouseenter() vs mouseover()

This example demonstrates the difference between the mousemove, mouseenter and mouseover events:


<div onmousemove="myMoveFunction()">
    <p>onmousemove: <br> <span id="demo">Mouse over me!</span></p>

<div onmouseenter="myEnterFunction()">
    <p>onmouseenter: <br> <span id="demo2">Mouse over me!</span></p>

<div onmouseover="myOverFunction()">
    <p>onmouseover: <br> <span id="demo3">Mouse over me!</span></p>


div {
    width: 200px;
    height: 100px;
    border: 1px solid black;
    margin: 10px;
    float: left;
    padding: 30px;
    text-align: center;
    background-color: lightgray;

p {
    background-color: white;
    height: 50px;

p span {
    background-color: #86fcd4;
    padding: 0 20px;


var x = 0;
var y = 0;
var z = 0;

function myMoveFunction() {
    document.getElementById("demo").innerHTML = z += 1;

function myEnterFunction() {
    document.getElementById("demo2").innerHTML = x += 1;

function myOverFunction() {
    document.getElementById("demo3").innerHTML = y += 1;
  • onmousemove : occurs every time the mouse pointer is moved over the div element.
  • onmouseenter : only occurs when the mouse pointer enters the div element.
  • onmouseover : occurs when the mouse pointer enters the div element, and its child elements (p and span).

Detect if a NumPy array contains at least one non-numeric value?

This should be faster than iterating and will work regardless of shape.


Edit: 30x faster:

import timeit
s = 'import numpy;a = numpy.arange(10000.).reshape((100,100));a[10,10]=numpy.nan'
ms = [
    'any(numpy.isnan(x) for x in a.flatten())']
for m in ms:
    print "  %.2f s" % timeit.Timer(m, s).timeit(1000), m


  0.11 s numpy.isnan(a).any()
  3.75 s any(numpy.isnan(x) for x in a.flatten())

Bonus: it works fine for non-array NumPy types:

>>> a = numpy.float64(42.)
>>> numpy.isnan(a).any()
>>> a = numpy.float64(numpy.nan)
>>> numpy.isnan(a).any()

Taking inputs with BufferedReader in Java

BufferedReader#read reads single character[0 to 65535 (0x00-0xffff)] from the stream, so it is not possible to read single integer from stream.

            String s= inp.readLine();
            int[] m= new int[2];
            String[] s1 = inp.readLine().split(" ");

            // Checking whether I am taking the inputs correctly

You can check also Scanner vs. BufferedReader.

How is VIP swapping + CNAMEs better than IP swapping + A records?

A VIP swap is an internal change to Azure's routers/load balancers, not an external DNS change. They're just routing traffic to go from one internal [set of] server[s] to another instead. Therefore the DNS info for doesn't change at all. Therefore the change for people accessing via the IP bound to (and CNAME'd by you) will see the change as soon as the VIP swap is complete.

Difference between "Complete binary tree", "strict binary tree","full binary Tree"?

Consider a binary tree whose nodes are drawn in a tree fashion. Now start numbering the nodes from top to bottom and left to right. A complete tree has these properties:

If n has children then all nodes numbered less than n have two children.

If n has one child it must be the left child and all nodes less than n have two children. In addition no node numbered greater than n has children.

If n has no children then no node numbered greater than n has children.

A complete binary tree can be used to represent a heap. It can be easily represented in contiguous memory with no gaps (i.e. all array elements are used save for any space that may exist at the end).

jQuery Validate Plugin - How to create a simple custom rule?

Step 1 Included the cdn like

     <script src=""></script>

     <script src=""></script>

Step 2 Code Like

        $("#submit").click(function () {
              $('#myform').validate({ // initialize the plugin
                rules: {
                    id: {
                        required: true,
                        email: true
                    password: {
                        required: true,
                        minlength: 1
                messages: {
                    id: {
                        required: "Enter Email Id"

                    password: {
                        required: "Enter Email Password"

                submitHandler: function (form) { // for demo
                    alert('valid form submitted'); // for demo
                    return false; // for demo

How should I make my VBA code compatible with 64-bit Windows?

Use PtrSafe and see how that works on Excel 2010.

Corrected typo from the book "Microsoft Excel 2010 Power Programming with VBA".

#If vba7 and win64 then
  declare ptrsafe function ....
  declare function ....
#End If

val(application.version)>12.0 won't work because Office 2010 has both 32 and 64 bit versions

How to disable copy/paste from/to EditText

If you are using API level 11 or above then you can stop copy,paste,cut and custom context menus from appearing by.

edittext.setCustomSelectionActionModeCallback(new ActionMode.Callback() {

            public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
                return false;

            public void onDestroyActionMode(ActionMode mode) {                  

            public boolean onCreateActionMode(ActionMode mode, Menu menu) {
                return false;

            public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
                return false;

Returning false from onCreateActionMode(ActionMode, Menu) will prevent the action mode from being started(Select All, Cut, Copy and Paste actions).

How to get the difference between two arrays of objects in JavaScript

You could use Array.prototype.filter() in combination with Array.prototype.some().

Here is an example (assuming your arrays are stored in the variables result1 and result2):

//Find values that are in result1 but not in result2
var uniqueResultOne = result1.filter(function(obj) {
    return !result2.some(function(obj2) {
        return obj.value == obj2.value;

//Find values that are in result2 but not in result1
var uniqueResultTwo = result2.filter(function(obj) {
    return !result1.some(function(obj2) {
        return obj.value == obj2.value;

//Combine the two arrays of unique entries
var result = uniqueResultOne.concat(uniqueResultTwo);

Compute elapsed time

<script type="text/javascript">
<!-- Gracefully hide from old browsers

// Javascript to compute elapsed time between "Start" and "Finish" button clicks
function timestamp_class(this_current_time, this_start_time, this_end_time, this_time_difference) { 
        this.this_current_time = this_current_time;
        this.this_start_time = this_start_time;
        this.this_end_time = this_end_time;
        this.this_time_difference = this_time_difference;
        this.GetCurrentTime = GetCurrentTime;
        this.StartTiming = StartTiming;
        this.EndTiming = EndTiming;

    //Get current time from date timestamp
    function GetCurrentTime() {
    var my_current_timestamp;
        my_current_timestamp = new Date();      //stamp current date & time
        return my_current_timestamp.getTime();

    //Stamp current time as start time and reset display textbox
    function StartTiming() {
        this.this_start_time = GetCurrentTime();    //stamp current time
        document.TimeDisplayForm.TimeDisplayBox.value = 0;  //init textbox display to zero

    //Stamp current time as stop time, compute elapsed time difference and display in textbox
    function EndTiming() {
        this.this_end_time = GetCurrentTime();      //stamp current time
        this.this_time_difference = (this.this_end_time - this.this_start_time) / 1000; //compute elapsed time
        document.TimeDisplayForm.TimeDisplayBox.value = this.this_time_difference;  //set elapsed time in display box

var time_object = new timestamp_class(0, 0, 0, 0);  //create new time object and initialize it


        <input type="button" value="Start" onClick="time_object.StartTiming()"; name="StartButton">
        <input type="button" value="Finish" onClick="time_object.EndTiming()"; name="EndButton">
    <form name="TimeDisplayForm">
    Elapsed time:
      <input type="text" name="TimeDisplayBox" size="6">

Can I add and remove elements of enumeration at runtime in Java

I faced this problem on the formative project of my young career.

The approach I took was to save the values and the names of the enumeration externally, and the end goal was to be able to write code that looked as close to a language enum as possible.

I wanted my solution to look like this:

enum HatType

HatType mine = HatType.BASEBALL;

// prints "BASEBALL"

// prints true

And I ended up with something like this:

// in a file somewhere:
// 1 --> BASEBALL
// 2 --> BRIMLESS

HatDynamicEnum hats = HatEnumRepository.retrieve();

HatEnumValue mine = hats.valueOf("BASEBALL");

// prints "BASEBALL"

// prints true

Since my requirements were that it had to be possible to add members to the enum at run-time, I also implemented that functionality:



hats = HatEnumRepository.retrieve();

HatEnumValue justArrived = hats.valueOf("BATTING_PRACTICE");
// file now reads:
// 1 --> BASEBALL
// 2 --> BRIMLESS

I dubbed it the Dynamic Enumeration "pattern", and you read about the original design and its revised edition.

The difference between the two is that the revised edition was designed after I really started to grok OO and DDD. The first one I designed when I was still writing nominally procedural DDD, under time pressure no less.

ASP.NET Identity reset password

I did a little investigation and the solution that works for me was a mix of a few solutions founded in this post.

I'm basically compiling this solution and I'm posting what works for me. In my case, I'm don't want to use any token from .net core.

public async Task ResetPassword(string userId, string password)
    var user = await _userManager.FindByIdAsync(userId);
    var hashPassword= _userManager.PasswordHasher.HashPassword(user, password);
    user.PasswordHash = passwordHash;
    await _userManager.UpdateAsync(user);


What is the most efficient way to deep clone an object in JavaScript?

// obj target object, vals source object
var setVals = function (obj, vals) {
    if (obj && vals) {
        for (var x in vals) {
            if (vals.hasOwnProperty(x)) {
                if (obj[x] && typeof vals[x] === 'object') {
                    obj[x] = setVals(obj[x], vals[x]);
                } else {
                    obj[x] = vals[x];
    return obj;

Formatting floats in a numpy array

In order to make numpy display float arrays in an arbitrary format, you can define a custom function that takes a float value as its input and returns a formatted string:

In [1]: float_formatter = "{:.2f}".format

The f here means fixed-point format (not 'scientific'), and the .2 means two decimal places (you can read more about string formatting here).

Let's test it out with a float value:

In [2]: float_formatter(1.234567E3)
Out[2]: '1234.57'

To make numpy print all float arrays this way, you can pass the formatter= argument to np.set_printoptions:

In [3]: np.set_printoptions(formatter={'float_kind':float_formatter})

Now numpy will print all float arrays this way:

In [4]: np.random.randn(5) * 10
Out[4]: array([5.25, 3.91, 0.04, -1.53, 6.68]

Note that this only affects numpy arrays, not scalars:

In [5]: np.pi
Out[5]: 3.141592653589793

It also won't affect non-floats, complex floats etc - you will need to define separate formatters for other scalar types.

You should also be aware that this only affects how numpy displays float values - the actual values that will be used in computations will retain their original precision.

For example:

In [6]: a = np.array([1E-9])

In [7]: a
Out[7]: array([0.00])

In [8]: a == 0
Out[8]: array([False], dtype=bool)

numpy prints a as if it were equal to 0, but it is not - it still equals 1E-9.

If you actually want to round the values in your array in a way that affects how they will be used in calculations, you should use np.round, as others have already pointed out.

How to "select distinct" across multiple data frame columns in pandas?

You can use the drop_duplicates method to get the unique rows in a DataFrame:

In [29]: df = pd.DataFrame({'a':[1,2,1,2], 'b':[3,4,3,5]})

In [30]: df
   a  b
0  1  3
1  2  4
2  1  3
3  2  5

In [32]: df.drop_duplicates()
   a  b
0  1  3
1  2  4
3  2  5

You can also provide the subset keyword argument if you only want to use certain columns to determine uniqueness. See the docstring.

pthread function from a class

This is a bit old question but a very common issue which many face. Following is a simple and elegant way to handle this by using std::thread

#include <iostream>
#include <utility>
#include <thread>
#include <chrono>

class foo
        void bar(int j)
            n = j;
            for (int i = 0; i < 5; ++i) {
                std::cout << "Child thread executing\n";
        int n = 0;

int main()
    int n = 5;
    foo f;
    std::thread class_thread(&foo::bar, &f, n); // t5 runs foo::bar() on object f
    std::cout << "Main Thread running as usual";
    std::cout << "Final value of foo::n is " << f.n << '\n';

Above code also takes care of passing argument to the thread function.

Refer std::thread document for more details.

What's the longest possible worldwide phone number I should consider in SQL varchar(length) for phone

In the GSM specification 3GPP TS 11.11, there are 10 bytes set aside in the MSISDN EF (6F40) for 'dialing number'. Since this is the GSM representation of a phone number, and it's usage is nibble swapped, (and there is always the possibility of parentheses) 22 characters of data should be plenty.

In my experience, there is only one instance of open/close parentheses, that is my reasoning for the above.

xsl: how to split strings?

I. Plain XSLT 1.0 solution:

This transformation:

<xsl:stylesheet version="1.0"
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="text()" name="split">
  <xsl:param name="pText" select="."/>
  <xsl:if test="string-length($pText)">
   <xsl:if test="not($pText=.)">
    <br />
   <xsl:value-of select=
   <xsl:call-template name="split">
    <xsl:with-param name="pText" select=
     "substring-after($pText, ';')"/>

when applied on this XML document:

<t>123 Elm Street;PO Box 222;c/o James Jones</t>

produces the wanted, corrected result:

123 Elm Street<br />PO Box 222<br />c/o James Jones

II. FXSL 1 (for XSLT 1.0):

Here we just use the FXSL template str-map (and do not have to write recursive template for the 999th time):

<xsl:stylesheet version="1.0" 
exclude-result-prefixes="xsl f testmap"
   <xsl:import href="str-dvc-map.xsl"/>


   <xsl:output omit-xml-declaration="yes" indent="yes"/>

   <xsl:template match="/">
     <xsl:variable name="vTestMap" select="document('')/*/testmap:*[1]"/>
     <xsl:call-template name="str-map">
       <xsl:with-param name="pFun" select="$vTestMap"/>
       <xsl:with-param name="pStr" select=
       "'123 Elm Street;PO Box 222;c/o James Jones'"/>

    <xsl:template name="replace" mode="f:FXSL"
         match="*[namespace-uri() = 'testmap']">
      <xsl:param name="arg1"/>

       <xsl:when test="not($arg1=';')">
        <xsl:value-of select="$arg1"/>
       <xsl:otherwise><br /></xsl:otherwise>

when this transformation is applied on any XML document (not used), the same, wanted correct result is produced:

123 Elm Street<br/>PO Box 222<br/>c/o James Jones

III. Using XSLT 2.0

<xsl:stylesheet version="2.0"
 <xsl:output omit-xml-declaration="yes" indent="yes"/>

 <xsl:template match="text()">
  <xsl:for-each select="tokenize(.,';')">
   <xsl:sequence select="."/>
   <xsl:if test="not(position() eq last())"><br /></xsl:if>

when this transformation is applied on this XML document:

<t>123 Elm Street;PO Box 222;c/o James Jones</t>

the wanted, correct result is produced:

123 Elm Street<br />PO Box 222<br />c/o James Jones

increment date by one month

If you want to get the date of one month from now you can do it like this

echo date('Y-m-d', strtotime('1 month'));

If you want to get the date of two months from now, you can achieve that by doing this

echo date('Y-m-d', strtotime('2 month'));

And so on, that's all.

How to do an Integer.parseInt() for a decimal number?

String s="0.01";
int i = Double.valueOf(s).intValue();

getFilesDir() vs Environment.getDataDirectory()

From the HERE and HERE

public File getFilesDir ()

Returns the absolute path to the directory on the filesystem where files created with openFileOutput(String, int) are stored.

public static File getExternalStorageDirectory ()

Return the primary external storage directory. This directory may not currently be accessible if it has been mounted by the user on their computer, has been removed from the device, or some other problem has happened. You can determine its current state with getExternalStorageState().

Note: don't be confused by the word "external" here. This directory can better be thought as media/shared storage. It is a filesystem that can hold a relatively large amount of data and that is shared across all applications (does not enforce permissions). Traditionally this is an SD card, but it may also be implemented as built-in storage in a device that is distinct from the protected internal storage and can be mounted as a filesystem on a computer.

On devices with multiple users (as described by UserManager), each user has their own isolated external storage. Applications only have access to the external storage for the user they're running as.

If you want to get your application path use getFilesDir() which will give you path /data/data/your package/files

You can get the path using the Environment var of your data/package using the

getExternalFilesDir(Environment.getDataDirectory().getAbsolutePath()).getAbsolutePath(); which will return the path from the root directory of your external storage as /storage/sdcard/Android/data/your pacakge/files/data

To access the external resources you have to provide the permission of WRITE_EXTERNAL_STORAGE and READ_EXTERNAL_STORAGE in your manifest.

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

Check out the Best Documentation to get the paths of direcorty

How to remove anaconda from windows completely?

Method1: To uninstall Anaconda3 go to the Anaconda3 folder, there u will be able to find an executable called Uninstall-Anaconda3.exe, double click on it. This should uninstall ur application. There are times when the shortcut of anaconda command prompt,jupyter notebook, spyder, etc exists, so delete those files too.

Method2 (Windows8): Go to control panel->Programs->Uninstall a Program and then select Anaconda3(Python3.1. 64-bit)in the menu.

Multi-Line Comments in Ruby?

Despite the existence of =begin and =end, the normal and a more correct way to comment is to use #'s on each line. If you read the source of any ruby library, you will see that this is the way multi-line comments are done in almost all cases.

How can I create a keystore?

You can create your keystore by exporting a signed APK. When you will try to export/build a signed APK, it will ask for a keystore.

You can choose your existing keystore or you can easily create a new one by clicking create new keystore

Here a link very useful and well-explained of how to create your keystore and generate a signed APK

THis link explained how to do it with Android Studio, but if I remember, it is pretty similar on Eclipse


Once you generate your keystore, keep it somewhere safe because you will need it to regenerate a new signed APK.

How do I export a project in the Android studio?

How to export a table dataframe in PySpark to csv?

If data frame fits in a driver memory and you want to save to local files system you can convert Spark DataFrame to local Pandas DataFrame using toPandas method and then simply use to_csv:


Otherwise you can use spark-csv:

  • Spark 1.3'mycsv.csv', 'com.databricks.spark.csv')
  • Spark 1.4+


In Spark 2.0+ you can use csv data source directly:


How to use HTTP.GET in AngularJS correctly? In specific, for an external API call?

I suggest you use Promise

myApp.service('dataService', function($http,$q) {

  delete $http.defaults.headers.common['X-Requested-With'];
  this.getData = function() {
     deferred = $q.defer();
         method: 'GET',
         url: '',
         params: 'limit=10, sort_by=created:desc',
         headers: {'Authorization': 'Token token=xxxxYYYYZzzz'}
         // With the data succesfully returned, we can resolve promise and we can access it in controller
          //let the function caller know the error
     return deferred.promise;

so In your controller you can use the method

myApp.controller('AngularJSCtrl', function($scope, dataService) {
    $ = null;
    dataService.getData().then(function(response) {
        $ = response;

promises are powerful feature of angularjs and it is convenient special if you want to avoid nesting callbacks.

Unzip files programmatically in .net

Until now, I was using cmd processes in order to extract an .iso file, copy it into a temporary path from server and extracted on a usb stick. Recently I've found that this is working perfectly with .iso's that are less than 10Gb. For a iso like 29Gb this method gets stuck somehow.

    public void ExtractArchive()

                Directory.Delete(copyISOLocation.OutputPath, true); 
            catch (Exception e) when (e is IOException || e is UnauthorizedAccessException)

            Process cmd = new Process();
            cmd.StartInfo.FileName = "cmd.exe";
            cmd.StartInfo.RedirectStandardInput = true;
            cmd.StartInfo.RedirectStandardOutput = true;
            cmd.StartInfo.CreateNoWindow = true;
            cmd.StartInfo.UseShellExecute = false;
            cmd.StartInfo.WindowStyle = ProcessWindowStyle.Normal;

            cmd.StartInfo.Arguments = "-R";

            cmd.Disposed += (sender, args) => {
                Console.WriteLine("CMD Process disposed");
            cmd.Exited += (sender, args) => {
                Console.WriteLine("CMD Process exited");
            cmd.ErrorDataReceived += (sender, args) => {
                Console.WriteLine("CMD Process error data received");
            cmd.OutputDataReceived += (sender, args) => {
                Console.WriteLine("CMD Process Output data received");




            cmd.StandardInput.WriteLine("cd C:\\\"Program Files (x86)\"\\7-Zip\\");

            cmd.StandardInput.WriteLine(string.Format("7z.exe x -o{0} {1}", copyISOLocation.OutputPath, copyISOLocation.TempIsoPath));

Prevent Bootstrap Modal from disappearing when clicking outside or pressing escape?

Your code is working when i click out side the modal, but if i use html input field inside modal-body then focus your cursor on that input then press esc key the modal has closed. Click here

Check if instance is of a type

Yes, the "is" keyword:

if (c is TForm)

See details on MSDN:

Checks if an object is compatible with a given type. For example, it can be determined if an object is compatible with the string type like this:

How to check that a JCheckBox is checked?

By using itemStateChanged(ItemListener) you can track selecting and deselecting checkbox (and do whatever you want based on it):

myCheckBox.addItemListener(new ItemListener() {
    public void itemStateChanged(ItemEvent e) {
        if(e.getStateChange() == ItemEvent.SELECTED) {//checkbox has been selected
            //do something...
        } else {//checkbox has been deselected
            //do something...

Java Swing itemStateChanged docu should help too. By using isSelected() method you can just test if actual is checkbox selected:


How to add AUTO_INCREMENT to an existing column?

ALTER TABLE Table name ADD column datatype AUTO_INCREMENT,ADD primary key(column);

Executing JavaScript without a browser?

JSDB, available for Linux, Windows, and Mac should fit the bill pretty well. It uses Mozilla's Spidermonkey Javascript engine and seems to be less of a hassle to install compared to node.js (at least last time I tried node.js a couple of years ago).

I found JSDB from this interesting list of Javascript shells:

Use child_process.execSync but keep output in console

Unless you redirect stdout and stderr as the accepted answer suggests, this is not possible with execSync or spawnSync. Without redirecting stdout and stderr those commands only return stdout and stderr when the command is completed.

To do this without redirecting stdout and stderr, you are going to need to use spawn to do this but it's pretty straight forward:

var spawn = require('child_process').spawn;

//kick off process of listing files
var child = spawn('ls', ['-l', '/']);

//spit stdout to screen
child.stdout.on('data', function (data) {   process.stdout.write(data.toString());  });

//spit stderr to screen
child.stderr.on('data', function (data) {   process.stdout.write(data.toString());  });

child.on('close', function (code) { 
    console.log("Finished with code " + code);

I used an ls command that recursively lists files so that you can test it quickly. Spawn takes as first argument the executable name you are trying to run and as it's second argument it takes an array of strings representing each parameter you want to pass to that executable.

However, if you are set on using execSync and can't redirect stdout or stderr for some reason, you can open up another terminal like xterm and pass it a command like so:

var execSync = require('child_process').execSync;

execSync("xterm -title RecursiveFileListing -e ls -latkR /");

This will allow you to see what your command is doing in the new terminal but still have the synchronous call.

How do I allow HTTPS for Apache on localhost?

This should be work Ubuntu, Mint similar with Apache2

It is a nice guide, so following this

and leaving your ssl.conf like this or similar similar

<VirtualHost _default_:443>
        ServerAdmin [email protected]
        ServerName localhost

        DocumentRoot /var/www

    SSLEngine on
    SSLCertificateFile /etc/apache2/ssl/apache.crt
    SSLCertificateKeyFile /etc/apache2/ssl/apache.key

you can get it.

Hope this help for linuxer

For each row in an R dataframe

First, Jonathan's point about vectorizing is correct. If your getWellID() function is vectorized, then you can skip the loop and just use cat or write.csv:

write.csv(data.frame(wellid=getWellID(well$name, well$plate), 
         value1=well$value1, value2=well$value2), file=outputFile)

If getWellID() isn't vectorized, then Jonathan's recommendation of using by or knguyen's suggestion of apply should work.

Otherwise, if you really want to use for, you can do something like this:

for(i in 1:nrow(dataFrame)) {
    row <- dataFrame[i,]
    # do stuff with row

You can also try to use the foreach package, although it requires you to become familiar with that syntax. Here's a simple example:

d <- data.frame(x=1:10, y=rnorm(10))
s <- foreach(d=iter(d, by='row'), .combine=rbind) %dopar% d

A final option is to use a function out of the plyr package, in which case the convention will be very similar to the apply function.

ddply(dataFrame, .(x), function(x) { # do stuff })

Create JPA EntityManager without persistence.xml configuration file

With plain JPA, assuming that you have a PersistenceProvider implementation (e.g. Hibernate), you can use the PersistenceProvider#createContainerEntityManagerFactory(PersistenceUnitInfo info, Map map) method to bootstrap an EntityManagerFactory without needing a persistence.xml.

However, it's annoying that you have to implement the PersistenceUnitInfo interface, so you are better off using Spring or Hibernate which both support bootstrapping JPA without a persistence.xml file:

this.nativeEntityManagerFactory = provider.createContainerEntityManagerFactory(

Where the PersistenceUnitInfo is implemented by the Spring-specific MutablePersistenceUnitInfo class.

How to click a browser button with JavaScript automatically?

This will give you some control over the clicking, and looks tidy

var timeOut = 0;
function onClick(but)
    timeOut = setTimeout(function (){onClick(but)},1000);
<button onclick="onClick(this)">Start clicking</button>

Change value of variable with dplyr

We can use replace to change the values in 'mpg' to NA that corresponds to cyl==4.

mtcars %>%
     mutate(mpg=replace(mpg, cyl==4, NA)) %>%

Image Processing: Algorithm Improvement for 'Coca-Cola Can' Recognition

If you are interested in it being realtime, then what you need is to add in a pre-processing filter to determine what gets scanned with the heavy-duty stuff. A good fast, very real time, pre-processing filter that will allow you to scan things that are more likely to be a coca-cola can than not before moving onto more iffy things is something like this: search the image for the biggest patches of color that are a certain tolerance away from the sqrt(pow(red,2) + pow(blue,2) + pow(green,2)) of your coca-cola can. Start with a very strict color tolerance, and work your way down to more lenient color tolerances. Then, when your robot runs out of an allotted time to process the current frame, it uses the currently found bottles for your purposes. Please note that you will have to tweak the RGB colors in the sqrt(pow(red,2) + pow(blue,2) + pow(green,2)) to get them just right.

Also, this is gona seem really dumb, but did you make sure to turn on -oFast compiler optimizations when you compiled your C code?

Set up Python simpleHTTPserver on Windows

From Stack Overflow question What is the Python 3 equivalent of "python -m SimpleHTTPServer":

The following works for me:

python -m http.server [<portNo>]

Because I am using Python 3 the module SimpleHTTPServer has been replaced by http.server, at least in Windows.

How to set the margin or padding as percentage of height of parent container?

An answer to a slightly different question: You can use vh units to pad elements to the center of the viewport:

.centerme {
    margin-top: 50vh;
    background: red;

<div class="centerme">middle</div>

Overlapping Views in Android

Visible gallery changes visibility which is how you get the gallery over other view overlap. the Home sample app has some good examples of this technique.

Convert string to a variable name

I was working with this a few days ago, and noticed that sometimes you will need to use the get() function to print the results of your variable. ie :

varnames = c('jan', 'feb', 'march')
file_names = list_files('path to multiple csv files saved on drive')
assign(varnames[1], read.csv(file_names[1]) # This will assign the variable

From there, if you try to print the variable varnames[1], it returns 'jan'. To work around this, you need to do print(get(varnames[1]))

mat-form-field must contain a MatFormFieldControl

New updated MatInput Module import is:

import {MatInputModule} from '@angular/material/input';

As per Angular Materials API

jQuery: Wait/Delay 1 second without executing code

function sleep(num) {
    var now = new Date();
    var stop = now.getTime() + num;
    while(true) {
        now = new Date();
        if(now.getTime() > stop) return;

sleep(1000);   // 1 second 

this code work well for me.

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

The ng-model and ng-checked directives should not be used together

From the Docs:


Sets the checked attribute on the element, if the expression inside ngChecked is truthy.

Note that this directive should not be used together with ngModel, as this can lead to unexpected behavior.

AngularJS ng-checked Directive API Reference

Instead set the desired initial value from the controller:

<input type="checkbox" name="test" ng-model="testModel['item1']" ?n?g?-?c?h?e?c?k?e?d?=?"?t?r?u?e?"? />
    Testing<br />
<input type="checkbox" name="test" ng-model="testModel['item2']" /> Testing 2<br />
<input type="checkbox" name="test" ng-model="testModel['item3']" /> Testing 3<br />
<input type="button" ng-click="submit()" value="Submit" />
$scope.testModel = { item1: true };

Selecting multiple items in ListView

Step 1: setAdapter to your listview.

 listView.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_multiple_choice, GENRES)); 

Step 2: set choice mode for listview .The second line of below code represents which checkbox should be checked.

listView.setItemChecked(2, true);


 private static  String[] GENRES = new String[] {
        "Action", "Adventure", "Animation", "Children", "Comedy", "Documentary", "Drama",
        "Foreign", "History", "Independent", "Romance", "Sci-Fi", "Television", "Thriller"

Step 3: Checked views are returned in SparseBooleanArray, so you might use the below code to get key or values.The below sample are simply displayed selected names in a single String.

    public void onItemClick(AdapterView<?> adapter, View arg1, int arg2, long arg3)

    SparseBooleanArray sp=getListView().getCheckedItemPositions();

    String str="";
    for(int i=0;i<sp.size();i++)
    Toast.makeText(this, ""+str, Toast.LENGTH_SHORT).show();


Create session factory in Hibernate 4

[quote from]

There are many APIs deprecated in the hibernate core framework. One of the frustrating point at this time is, hibernate official documentation is not providing the clear instructions on how to use the new API and it stats that the documentation is in complete. Also each incremental version gets changes on some of the important API. One such thing is the new API for creating the session factory in Hibernate 4.3.0 on wards. In our earlier versions we have created the session factory as below:

SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();

The method buildSessionFactory is deprecated from the hibernate 4 release and it is replaced with the new API. If you are using the hibernate 4.3.0 and above, your code has to be:

Configuration configuration = new Configuration().configure();

StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties());

SessionFactory factory = configuration.buildSessionFactory(;

Class ServiceRegistryBuilder is replaced by StandardServiceRegistryBuilder from 4.3.0. It looks like there will be lot of changes in the 5.0 release. Still there is not much clarity on the deprecated APIs and the suitable alternatives to use. Every incremental release comes up with more deprecated API, they are in way of fine tuning the core framework for the release 5.0.

How to send a POST request using volley with string body?

I liked this one, but it is sending JSON not string as requested in the question, reposting the code here, in case the original github got removed or changed, and this one found to be useful by someone.

public static void postNewComment(Context context,final UserAccount userAccount,final String comment,final int blogId,final int postId){
    RequestQueue queue = Volley.newRequestQueue(context);
    StringRequest sr = new StringRequest(Request.Method.POST,"", new Response.Listener<String>() {
        public void onResponse(String response) {
    }, new Response.ErrorListener() {
        public void onErrorResponse(VolleyError error) {
        protected Map<String,String> getParams(){
            Map<String,String> params = new HashMap<String, String>();
            params.put("comment", Uri.encode(comment));

            return params;

        public Map<String, String> getHeaders() throws AuthFailureError {
            Map<String,String> params = new HashMap<String, String>();
            return params;

public interface PostCommentResponseListener {
    public void requestStarted();
    public void requestCompleted();
    public void requestEndedWithError(VolleyError error);

MySql: is it possible to 'SUM IF' or to 'COUNT IF'?

you want something like:

SELECT count(id), SUM(hour) as totHour, SUM(kind=1) as countKindOne;

Note that your second example was close, but the IF() function always takes three arguments, so it would have had to be COUNT(IF(kind=1,1,NULL)). I prefer the SUM() syntax shown above because it's concise.

How can I add an item to a SelectList in MVC

Okay I like clean code so I made this an extension method

static public class SelectListHelper
    static public SelectList Add(this SelectList list, string text, string value = "", ListPosition listPosition = ListPosition.First)
        if (string.IsNullOrEmpty(value))
            value = text;
        var listItems = list.ToList();
        var lp = (int)listPosition;
        switch (lp)
            case -1:
                lp = list.Count();
            case -2:
                lp = list.Count() / 2;
            case -3:
                var random = new Random();
                lp = random.Next(0, list.Count());
        listItems.Insert(lp, new SelectListItem { Value = value, Text = text });
        list = new SelectList(listItems, "Value", "Text");
        return list;

    public enum ListPosition
        First = 0,
        Last = -1,
        Middle = -2,
        Random = -3

Usage (by example):

var model = new VmRoutePicker
     Routes =
     new SelectList(_dataSource.Routes.Select(r => r.RouteID).Distinct())
  model.Routes = model.Routes.Add("All", "All", SelectListHelper.ListPosition.Random);
  model.Routes = model.Routes.Add("All");

PHP & localStorage;

localStorage is something that is kept on the client side. There is no data transmitted to the server side.

You can only get the data with JavaScript and you can send it to the server side with Ajax.

Check if space is in a string

== takes precedence over in, so you're actually testing word == True.

>>> w = 'ab c'
>>> ' ' in w == True
1: False
>>> (' ' in w) == True
2: True

But you don't need == True at all. if requires [something that evalutes to True or False] and ' ' in word will evalute to true or false. So, if ' ' in word: ... is just fine:

>>> ' ' in w
3: True

How can one use multi threading in PHP applications

As of the writing of my current comment, I don't know about the PHP threads. I came to look for the answer here myself, but one workaround is that the PHP program that receives the request from the web server delegates the whole answer formulation to a console application that stores its output, the answer to the request, to a binary file and the PHP program that launched the console application returns that binary file byte-by-byte as the answer to the received request. The console application can be written in any programming language that runs on the server, including those that have proper threading support, including C++ programs that use OpenMP.

One unreliable, dirty, trick is to use PHP for executing a console application, "uname",

uname -a

and print the output of that console command to the HTML output to find out the exact version of the server software. Then install the exact same version of the software to a VirtualBox instance, compile/assemble whatever fully self-contained, preferably static, binaries that one wants and then upload those to the server. From that point onwards the PHP application can use those binaries in the role of the console application that has proper multi-threading. It's a dirty, unreliable, workaround to a situation, when the server administrator has not installed all needed programming language implementations to the server. The thing to watch out for is that at every request that the PHP application receives the console application(s) terminates/exit/get_killed.

As to what the hosting service administrators think of such server usage patterns, I guess it boils down to culture. In Northern Europe the service provider HAS TO DELIVER WHAT WAS ADVERTISED and if execution of console commands was allowed and uploading of non-malware files was allowed and the service provider has a right to kill any server process after a few minutes or even after 30 seconds, then the hosting service administrators lack any arguments for forming a proper complaint. In United States and Western Europe the situation/culture is very different and I believe that there's a great chance that in U.S. and/or Western Europe the hosting service provider will refuse to serve hosting service clients that use the above described trick. That's just my guess, given my personal experience with U.S. hosting services and given what I have heard from others about Western European hosting services. As of the writing of my current comment(2018_09_01) I do not know anything about the cultural norms of the Southern-European hosting service providers, Southern-European network administrators.

SQLite add Primary Key


This is based on Android's java and it's a good example on changing the database without annoying your application fans/customers. This is based on the idea of the SQLite FAQ page

The problem

I did not notice that I need to set a row_number or record_id to delete a single purchased item in a receipt, and at same time the item barcode number fooled me into thinking of making it as the key to delete that item. I am saving a receipt details in the table receipt_barcode. Leaving it without a record_id can mean deleting all records of the same item in a receipt if I used the item barcode as the key.


Please understand that this is a copy-paste of my code I am work on at the time of this writing. Use it only as an example, copy-pasting randomly won't help you. Modify this first to your needs

Also please don't forget to read the comments in the code .

The Code

Use this as a method in your class to check 1st whether the column you want to add is missing . We do this just to not repeat the process of altering the table receipt_barcode. Just mention it as part of your class. In the next step you'll see how we'll use it.

public boolean is_column_exists(SQLiteDatabase mDatabase , String table_name,
String     column_name) {
    //checks if table_name has column_name
    Cursor cursor = mDatabase.rawQuery("pragma table_info("+table_name+")",null);
    while (cursor.moveToNext()){
    if (cursor.getString(cursor.getColumnIndex("name")).equalsIgnoreCase(column_name)) return true;
    return false;

Then , the following code is used to create the table receipt_barcode if it already does NOT exit for the 1st time users of your app. And please notice the "IF NOT EXISTS" in the code. It has importance.

//mDatabase should be defined as a Class member (global variable) 
//for ease of access : 
//SQLiteDatabse mDatabase=SQLiteDatabase.openOrCreateDatabase(dbfile_path, null);
creation_query = " CREATE TABLE if not exists receipt_barcode ( ";
creation_query += "\n record_id        INTEGER PRIMARY KEY AUTOINCREMENT,";
creation_query += "\n rcpt_id INT( 11 )       NOT NULL,";
creation_query += "\n barcode VARCHAR( 255 )  NOT NULL ,";
creation_query += "\n barcode_price VARCHAR( 255 )  DEFAULT (0),";
creation_query += "\n PRIMARY KEY ( record_id ) );";

//This is where the important part comes in regarding the question in this page:

//adding the missing primary key record_id in table receipt_barcode for older versions
        if (!is_column_exists(mDatabase, "receipt_barcode","record_id")){
                Log.e("record_id", "creating");

                 creation_query="CREATE TEMPORARY TABLE t1_backup(";
                 creation_query+="record_id INTEGER        PRIMARY KEY AUTOINCREMENT,";
                 creation_query+="rcpt_id INT( 11 )       NOT NULL,";
                 creation_query+="barcode VARCHAR( 255 )  NOT NULL ,";
                 creation_query+="barcode_price VARCHAR( 255 )  NOT NULL DEFAULT (0) );";

                 creation_query="INSERT INTO t1_backup(rcpt_id,barcode,barcode_price) SELECT rcpt_id,barcode,barcode_price  FROM receipt_barcode;";

                 creation_query="DROP TABLE receipt_barcode;";

                 creation_query="CREATE TABLE receipt_barcode (";
                 creation_query+="record_id INTEGER        PRIMARY KEY AUTOINCREMENT,";
                 creation_query+="rcpt_id INT( 11 )       NOT NULL,";
                 creation_query+="barcode VARCHAR( 255 )  NOT NULL ,";
                 creation_query+="barcode_price VARCHAR( 255 )  NOT NULL DEFAULT (0) );";

                 creation_query="INSERT INTO receipt_barcode(record_id,rcpt_id,barcode,barcode_price) SELECT record_id,rcpt_id,barcode,barcode_price  FROM t1_backup;";

                 creation_query="DROP TABLE t1_backup;";

            } catch (Exception exception ){
                Log.e("table receipt_bracode", "Table receipt_barcode did not get a primary key (record_id");
            } finally {

How to find the lowest common ancestor of two nodes in any binary tree?

Solution 1: Recursive - Faster

  • The idea is to traverse the tree starting from root. If any of the given keys p and q matches with root, then root is LCA, assuming that both keys are present. If root doesn’t match with any of the keys, we recurse for left and right subtree.
  • The node which has one key present in its left subtree and the other key present in right subtree is the LCA. If both keys lie in left subtree, then left subtree has LCA also, otherwise LCA lies in right subtree.
  • Time Complexity: O(n)
  • Space Complexity: O(h) - for recursive call stack
class Solution 
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q)
        if(root == null || root == p  || root == q)
            return root;

        TreeNode left = lowestCommonAncestor(root.left, p, q);
        TreeNode right = lowestCommonAncestor(root.right, p, q);

        if(left == null)
            return right;
        else if(right == null)
            return left;
            return root;    // If(left != null && right != null)

Solution 2: Iterative - Using parent pointers - Slower

  • Create an empty hash table.
  • Insert p and all of its ancestors in hash table.
  • Check if q or any of its ancestors exist in hash table, if yes then return the first existing ancestor.
  • Time Complexity: O(n) - In the worst case we might be visiting all the nodes of binary tree.
  • Space Complexity: O(n) - Space utilized the parent pointer Hash-table, ancestor_set and queue, would be O(n) each.
class Solution
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q)
        HashMap<TreeNode, TreeNode> parent_map = new HashMap<>();
        HashSet<TreeNode> ancestors_set = new HashSet<>();
        Queue<TreeNode> queue = new LinkedList<>();

        parent_map.put(root, null);

        while(!parent_map.containsKey(p) || !parent_map.containsKey(q))
            TreeNode node = queue.poll();

            if(node.left != null)
                parent_map.put(node.left, node);
            if(node.right != null)
                parent_map.put(node.right, node);

        while(p != null)
            p = parent_map.get(p);

            q = parent_map.get(q);

        return q;

How can I force division to be floating point? Division keeps rounding down to 0?

from operator import truediv

c = truediv(a, b)

where a is dividend and b is the divisor. This function is handy when quotient after division of two integers is a float.

Fix Access denied for user 'root'@'localhost' for phpMyAdmin

@Dagon had the right idea but was a little short on details.

If you use the access and have a close look at the Users that are setup in MysQL you should see 3 versions of the root username.

This is because in MySQL each userid is associated with a HOST, i.e. The PC ( ip address ) that the user is allowed to sign in from. So your 3 `'root' userids are in fact the same userid which is allowed to signin from 3 seperate HOSTS. Normally out of the box the 'root' has 3 HOSTS setup,, localhost and ::1

These are :-

localhost is an alias for THIS MACHINE created from your HOSTS file ( c:\windows\system32\drivers\etc\hosts ) is the IPv4 loopback ip address of THIS MACHINE

::1 is the IPv6 loopback ip address of THIS MACHINE

What is probably happening to you is that you have set a password for [email protected] but not any of the others. Now your browser will 'arbtrarily' decide to use ::1 or as the host ip so when it uses ::1 your login will fail.

So login using and change all 3 'root' usernames to have the same password you should no longer see this problem.

Also make sure that your HOSTS file has these 2 entries  localhost
::1        localhost

Convert text to columns in Excel using VBA

Try this

Sub Txt2Col()
    Dim rng As Range

    Set rng = [C7]
    Set rng = Range(rng, Cells(Rows.Count, rng.Column).End(xlUp))

    rng.TextToColumns Destination:=rng, DataType:=xlDelimited, ' rest of your settings

Update: button click event to act on another sheet

Private Sub CommandButton1_Click()
    Dim rng As Range
    Dim sh As Worksheet

    Set sh = Worksheets("Sheet2")
    With sh
        Set rng = .[C7]
        Set rng = .Range(rng, .Cells(.Rows.Count, rng.Column).End(xlUp))

        rng.TextToColumns Destination:=rng, DataType:=xlDelimited, _
        TextQualifier:=xlDoubleQuote,  _
        ConsecutiveDelimiter:=False, _
        Tab:=False, _
        Semicolon:=False, _
        Other:=False, _
        FieldInfo:=Array(Array(1, xlGeneralFormat), Array(2, xlGeneralFormat), Array(3, xlGeneralFormat)), _
    End With
End Sub

Note the .'s (eg .Range) they refer to the With statement object

How to use MySQL dump from a remote machine

mysqldump -h [domain name/ip] -u [username] -p[password] [databasename] > [filename.sql]

How do I vertically align text in a paragraph?

In my case margin auto works fine.

p {
    font: 22px/24px Ubuntu;
    margin:auto 0px;

Replace multiple characters in one replace call

Use the OR operator (|):

var str = '#this #is__ __#a test###__';
str.replace(/#|_/g,''); // result: "this is a test"

You could also use a character class:



If you want to replace the hash with one thing and the underscore with another, then you will just have to chain. However, you could add a prototype:

String.prototype.allReplace = function(obj) {
    var retStr = this;
    for (var x in obj) {
        retStr = retStr.replace(new RegExp(x, 'g'), obj[x]);
    return retStr;

console.log('aabbaabbcc'.allReplace({'a': 'h', 'b': 'o'}));
// console.log 'hhoohhoocc';

Why not chain, though? I see nothing wrong with that.

setting system property

For JBoss, in standalone.xml, put after .


    <property name="my.project.dir" value="/home/francesco" />

For eclipse:

How to reference a method in javadoc?

you can use @see to do that:


interface View {
         * @return true: have read contact and call log permissions, else otherwise
         * @see #requestReadContactAndCallLogPermissions()
        boolean haveReadContactAndCallLogPermissions();

         * if not have permissions, request to user for allow
         * @see #haveReadContactAndCallLogPermissions()
        void requestReadContactAndCallLogPermissions();

How to make <a href=""> link look like a button?

You can create a class for the anchor elements that you would like to display as buttons.


Using an image :

.button {
   background: url('image');
   width: same as image
   height: same as image

or using a pure CSS approach:

.button {
    border: 1px solid #BBBBBB;
    border-radius: 3px 3px 3px 3px;

Always remember to hide the text with something like:

text-indent: -9999em;

An excellent gallery of pure CSS buttons is here and you can even use the css3 button generator

Plenty of styles and choices are here

good luck

How to automatically allow blocked content in IE?

Steps to configure IE to always allow blocked content:

  1. From Internet Explorer, select the Tools menu, then the Options...
  2. In the Internet Options dialog, select the Advanced tab...
  3. Scroll down until you see the Security options. Enable the checkbox "Allow active content to run in files on My Computer".

enter image description here

  1. Close the dialog, and quit Internet Explorer. The changes will take effect the next time you start IE.

The Blocked Content is a security feature of Windows XP Service Pack 2. If you do not have SP2 installed, then you will never see this message.

From: How To Allow Blocked Content on Internet Explorer

Twitter Bootstrap Multilevel Dropdown Menu

[Twitter Bootstrap v3]

To create a n-level dropdown menu (touch device friendly) in Twitter Bootstrap v3,


.dropdown-menu>li /* To prevent selection of text */
{   position:relative;
    -webkit-user-select: none; /* Chrome/Safari */        
    -moz-user-select: none; /* Firefox */
    -ms-user-select: none; /* IE10+ */
    /* Rules below not implemented in browsers yet */
    -o-user-select: none;
    user-select: none;
.dropdown-menu .sub-menu 
    left: 100%;
    position: absolute;
    top: 0;
    margin-top: -1px;
 {  content:"";
    border-bottom: 5px solid transparent;
    border-top: 5px solid transparent;
    display: inline-block;
    height: 0;
    vertical-align: middle;
    width: 0;
{   border-left: 5px solid #ffaf46;
{   border-right: 5px solid #ffaf46;


    $(".dropdown-menu > li > a.trigger").on("click",function(e){
        var current=$(this).next();
        var grandparent=$(this).parent().parent();
            $(this).toggleClass('right-caret left-caret');
        grandparent.find('.left-caret').not(this).toggleClass('right-caret left-caret');
    $(".dropdown-menu > li > a:not(.trigger)").on("click",function(){
        var root=$(this).closest('.dropdown');
        root.find('.left-caret').toggleClass('right-caret left-caret');


<div class="dropdown" style="position:relative">
    <a href="#" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">Click Here <span class="caret"></span></a>
    <ul class="dropdown-menu">
            <a class="trigger right-caret">Level 1</a>
            <ul class="dropdown-menu sub-menu">
                <li><a href="#">Level 2</a></li>
                    <a class="trigger right-caret">Level 2</a>
                    <ul class="dropdown-menu sub-menu">
                        <li><a href="#">Level 3</a></li>
                        <li><a href="#">Level 3</a></li>
                            <a class="trigger right-caret">Level 3</a>
                            <ul class="dropdown-menu sub-menu">
                                <li><a href="#">Level 4</a></li>
                                <li><a href="#">Level 4</a></li>
                                <li><a href="#">Level 4</a></li>
                <li><a href="#">Level 2</a></li>
        <li><a href="#">Level 1</a></li>
        <li><a href="#">Level 1</a></li>

RESTful URL design for search

There are a lot of good options for your case here. Still you should considering using the POST body.

The query string is perfect for your example, but if you have something more complicated, e.g. an arbitrary long list of items or boolean conditionals, you might want to define the post as a document, that the client sends over POST.

This allows a more flexible description of the search, as well as avoids the Server URL length limit.

How to Consolidate Data from Multiple Excel Columns All into One Column

The formula


placed into each cell of your second workbook will retrieve the appropriate cell from the source sheet. No macros, simple copying from one sheet to another to reformat the results.

You will need to modify the ranges in the COUNT function to match the maximum number of rows in the source sheet. Adjust for column headers as required.

If you need something other than a 0 for empty cells, you may prefer to include a conditional.

A script to reformat the data may well be more efficient, but 20k rows is no longer a real limit in a modern Excel workbook.

How to find the users list in oracle 11g db?

I tried this query and it works for me.

SELECT username FROM dba_users 
ORDER BY username;

If you want to get the list of all that users which are created by end-user, then you can try this:

SELECT username FROM dba_users where Default_TableSpace not in ('SYSAUX', 'SYSTEM', 'USERS')
ORDER BY username;

Async await in linq select

"Just because you can doesn't mean you should."

You can probably use async/await in LINQ expressions such that it will behave exactly as you want it to, but will any other developer reading your code still understand its behavior and intent?

(In particular: Should the async operations be run in parallel or are they intentionally sequential? Did the original developer even think about it?)

This is also shown clearly by the question, which seems to have been asked by a developer trying to understand someone else's code, without knowing its intent. To make sure this does not happen again, it may be best to rewrite the LINQ expression as a loop statement, if possible.

TensorFlow ValueError: Cannot feed value of shape (64, 64, 3) for Tensor u'Placeholder:0', which has shape '(?, 64, 64, 3)'

Powder's comment may go undetected like I missed it so many times,. So with the hope of making it more visible, I will re-iterate his point.

Sometimes using image = array(img).reshape(a,b,c,d) will reshape alright but from experience, my kernel crashes every time I try to use the new dimension in an operation. The safest to use is

np.expand_dims(img, axis=0)

It works perfect every time. I just can't explain why. This link has a great explanation and examples regarding its usage.

HTTP Error 500.30 - ANCM In-Process Start Failure

I got the same error on my development machine running Windows 10. The error did not go away after I installed dotnet core hosting bundle. I had to go to Event Viewer to get the detailed error. Your underlying issue (if any) may be different than mine. Point is, if you're on a Windows machine, Event Viewer is there to provide details. Hope this helps someone.

event viewer provided error details

Function Pointers in Java

There is no such thing in Java. You will need to wrap your function into some object and pass the reference to that object in order to pass the reference to the method on that object.

Syntactically, this can be eased to a certain extent by using anonymous classes defined in-place or anonymous classes defined as member variables of the class.


class MyComponent extends JPanel {
    private JButton button;
    public MyComponent() {
        button = new JButton("click me");

    private ActionListener buttonAction = new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            // handle the event...
            // note how the handler instance can access 
            // members of the surrounding class
            button.setText("you clicked me");

How to convert JSON object to JavaScript array?

You can insert object items to an array as this

let obj = {_x000D_
  '1st': {_x000D_
    name: 'stackoverflow'_x000D_
  '2nd': {_x000D_
    name: 'stackexchange'_x000D_
 let wholeArray = Object.keys(obj).map(key => obj[key]);_x000D_

PHP Unset Array value effect on other indexes

The keys are maintained with the removed key missing but they can be rearranged by doing this:

$array = array(1,2,3,4,5);
$arranged = array_values($array);


    [0] => 1
    [1] => 2
    [2] => 4
    [3] => 5

Notice that if we do the following without rearranging:


The index of the value 3 will be 5 because it will be pushed to the end of the array and will not try to check or replace missing index. This is important to remember when using FOR LOOP with index access.

Add left/right horizontal padding to UILabel

For a full list of available solutions, see this answer: UILabel text margin

Try subclassing UILabel, like @Tommy Herbert suggests in the answer to [this question][1]. Copied and pasted for your convenience:

I solved this by subclassing UILabel and overriding drawTextInRect: like this:

- (void)drawTextInRect:(CGRect)rect {
    UIEdgeInsets insets = {0, 5, 0, 5};
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];

What is com.sun.proxy.$Proxy

  1. Proxies are classes that are created and loaded at runtime. There is no source code for these classes. I know that you are wondering how you can make them do something if there is no code for them. The answer is that when you create them, you specify an object that implements InvocationHandler, which defines a method that is invoked when a proxy method is invoked.

  2. You create them by using the call

    Proxy.newProxyInstance(classLoader, interfaces, invocationHandler)

    The arguments are:

    1. classLoader. Once the class is generated, it is loaded with this class loader.
    2. interfaces. An array of class objects that must all be interfaces. The resulting proxy implements all of these interfaces.
    3. invocationHandler. This is how your proxy knows what to do when a method is invoked. It is an object that implements InvocationHandler. When a method from any of the supported interfaces, or hashCode, equals, or toString, is invoked, the method invoke is invoked on the handler, passing the Method object for the method to be invoked and the arguments passed.

    For more on this, see the documentation for the Proxy class.

  3. Every implementation of a JVM after version 1.3 must support these. They are loaded into the internal data structures of the JVM in an implementation-specific way, but it is guaranteed to work.

How to Select Every Row Where Column Value is NOT Distinct

This is significantly faster than the EXISTS way:

SELECT [EmailAddress], [CustomerName] FROM [Customers] WHERE [EmailAddress] IN
  (SELECT [EmailAddress] FROM [Customers] GROUP BY [EmailAddress] HAVING COUNT(*) > 1)

How to display hidden characters by default (ZERO WIDTH SPACE ie. &#8203)

Not sure what you meant, but you can permanently turn showing whitespaces on and off in Settings -> Editor -> General -> Appearance -> Show whitespaces.

Also, you can set it for a current file only in View -> Active Editor -> Show WhiteSpaces.


Had some free time since it looks like a popular issue, I had written a plugin to inspect the code for such abnormalities. It is called Zero Width Characters locator and you're welcome to give it a try.

Vim autocomplete for Python

As pointed out by in the comments, this answers is outdated. youcompleteme now supports python3 and jedi-vim no longer breaks the undo history.

Original answer below.

AFAIK there are three options, each with its disadvantages:

  1. youcompleteme: unfriendly to install, but works nice if you manage to get it working. However python3 is not supported.
  2. jedi-vim: coolest name, but breaks your undo history.
  3. python-mode does a lot more the autocomplete: folding, syntax checking, highlighting. Personally I prefer scripts that do 1 thing well, as they are easier to manage (and replace). Differently from the two other options, it uses rope instead of jedi for autocompletion.

Python 3 and undo history (gundo!) are a must for me, so options 1 and 2 are out.

Open File in Another Directory (Python)

import os
import os.path
import shutil

You find your current directory:

d = os.getcwd() #Gets the current working directory

Then you change one directory up:

os.chdir("..") #Go up one directory from working directory

Then you can get a tupple/list of all the directories, for one directory up:

o = [os.path.join(d,o) for o in os.listdir(d) if os.path.isdir(os.path.join(d,o))] # Gets all directories in the folder as a tuple

Then you can search the tuple for the directory you want and open the file in that directory:

for item in o:
    if os.path.exists(item + '\\testfile.txt'):
    file = item + '\\testfile.txt'

Then you can do stuf with the full file path 'file'

bower command not found

Alternatively, you can use npx which comes along with the npm > 5.6.

npx bower install

Is it possible to overwrite a function in PHP

short answer is no, you can't overwrite a function once its in the PHP function scope.

your best of using anonymous functions like so

$ihatefooexamples = function()
  return "boo-foo!";

$ihatefooexamples = function()
   return "really boo-foo";

Textarea onchange detection

You can listen to event on change of textarea and do the changes as per you want. Here is one example.

const textArea = document.getElementById('my_text_area');
textArea.addEventListener('input', () => {
    var textLn =  textArea.value.length;
    if(textLn >= 100) { = '10pt';
    <textarea id='my_text_area' rows="4" cols="50" style="font-size:40pt">
This text will change font after 100.

Convert HTML + CSS to PDF

Checkout TCPDF. It has some HTML to PDF functionality that might be enough for what you need. It's also free!

How do I programmatically "restart" an Android app?

You can use startInstrumentation method of Activity. You need implement empty Instrumentation and pointed in manifest. After that you can call this method for restart your app. Like this:

try {           
    InstrumentationInfo info = getPackageManager().queryInstrumentation(getPackageName(), 0).get(0);
    ComponentName component = new ComponentName(this, Class.forName(;
    startInstrumentation(component, null, null);
} catch (Throwable e) {             
    new RuntimeException("Failed restart with Instrumentation", e);

I get Instrumentation class name dynamically but you can hardcode it. Some like this:

try {           
    startInstrumentation(new ComponentName(this, RebootInstrumentation.class), null, null); 
} catch (Throwable e) {             
    new RuntimeException("Failed restart with Instrumentation", e);

Call startInstrumentation make reload of your app. Read description of this method. But it can be not safe if acting like kill app.

Difference between 3NF and BCNF in simple terms (must be able to explain to an 8-year old)

The subtle difference is that 3NF makes a distinction between key and non-key attributes (also called non-prime attributes) whereas BCNF does not.

This is best explained using Zaniolo's definition of 3NF, which is equivalent to Codd's:

A relation, R, is in 3NF iff for every nontrivial FD (X->A) satisfied by R at least ONE of the following conditions is true:

(a) X is a superkey for R, or

(b) A is a key attribute for R

BCNF requires (a) but doesn't treat (b) as a special case of its own. In other words BCNF requires that every nontrivial determinant is a superkey even its dependent attributes happen to be part of a key.

A relation, R, is in BCNF iff for every nontrivial FD (X->A) satisfied by R the following condition is true:

(a) X is a superkey for R

BCNF is therefore more strict.

The difference is so subtle that what many people informally describe as 3NF is actually BCNF. For example, you stated here that 3NF means "data depends on the key[s]... and nothing but the key[s]", but that is really an informal description of BCNF and not 3NF. 3NF could more accurately be described as "non-key data depends on the keys... and nothing but the keys".

You also stated:

the 3NF quote explicitly says "nothing but the key" meaning that all attributes depend solely on the primary key.

That's an oversimplification. 3NF and BCNF and all the Normal Forms are concerned with all candidate keys and/or superkeys, not just one "primary" key.

ASP.NET MVC - passing parameters to the controller

Or, you could try changing the parameter type to string, then convert the string to an integer in the method. I am new to MVC, but I believe you need nullable objects in your parameter list, how else will the controller indicate that no such parameter was provided? So...

public ActionResult ViewNextItem(string id)...

nginx: connect() failed (111: Connection refused) while connecting to upstream

I don't think that solution would work anyways because you will see some error message in your error log file.

The solution was a lot easier than what I thought.

simply, open the following path to your php5-fpm

sudo nano /etc/php5/fpm/pool.d/www.conf

or if you're the admin 'root'

nano /etc/php5/fpm/pool.d/www.conf

Then find this line and uncomment it:

listen.allowed_clients =

This solution will make you be able to use listen = in your vhost blocks

like this: fastcgi_pass;

after you make the modifications, all you need is to restart or reload both Nginx and Php5-fpm


sudo service php5-fpm restart


sudo service php5-fpm reload


sudo service nginx restart


sudo service nginx reload

From the comments:

Also comment

;listen = /var/run/php5-fpm.sock 

and add

listen = 9000

Deploying just HTML, CSS webpage to Tomcat

Here's my step in Ubuntu 16.04 and Tomcat 8.

  1. Copy folder /var/lib/tomcat8/webapps/ROOT to your folder.

    cp -r /var/lib/tomcat8/webapps/ROOT /var/lib/tomcat8/webapps/{yourfolder}

  2. Add your html, css, js, to your folder.

  3. Open "http://localhost:8080/{yourfolder}" in browser


  1. If you using chrome web browser and did wrong folder before, then clean web browser's cache(or change another name) otherwise (sometimes) it always 404.

  2. The folder META-INF with context.xml is needed.

How do I get an empty array of any size in python?

also you can extend that with extend method of list.

a= []

JavaScript property access: dot notation vs. brackets?

Dot notation does not work with some keywords (like new and class) in internet explorer 8.

I had this code:

//app.users is a hash = {
  // some code

And this triggers the dreaded "expected indentifier" (at least on IE8 on windows xp, I havn't tried other environments). The simple fix for that is to switch to bracket notation:

app.users['new'] = {
  // some code

How can I remove text within parentheses with a regex?

Java code:

Pattern pattern1 = Pattern.compile("(\\_\\(.*?\\))");
System.out.println(fileName.replace(, ""));

How to initialize a dict with keys from a list and empty value in Python?

>>> keyDict = {"a","b","c","d"}

>>> dict([(key, []) for key in keyDict])


{'a': [], 'c': [], 'b': [], 'd': []}

Adding attributes to an XML node

Well id isn't really the root node: Login is.

It should just be a case of specifying the attributes (not tags, btw) using XmlElement.SetAttribute. You haven't specified how you're creating the file though - whether you're using XmlWriter, the DOM, or any other XML API.

If you could give an example of the code you've got which isn't working, that would help a lot. In the meantime, here's some code which creates the file you described:

using System;
using System.Xml;

class Test
    static void Main()
        XmlDocument doc = new XmlDocument();
        XmlElement root = doc.CreateElement("Login");
        XmlElement id = doc.CreateElement("id");
        id.SetAttribute("userName", "Tushar");
        id.SetAttribute("passWord", "Tushar");
        XmlElement name = doc.CreateElement("Name");
        name.InnerText = "Tushar";
        XmlElement age = doc.CreateElement("Age");
        age.InnerText = "24";



Checking character length in ruby

Verification, do not forget the to_s

 def nottolonng?(value)
   if value.to_s.length <=8
     return true
     return false

HashMap and int as key

The main reason with HashMap not allowing primitive as keys is that HashMap is designed in such a way that for comparing the keys, it makes use of equals() method, and a method can be called only on an object not on a primitive.

Thus when int is autoboxed to Integer, Hashmap can call equals() method on Integer object.

That is why, you should use Integer instead of int. I mean hashmap throws an error while putting int as a key (Don't know the meaning of the error that is thrown)

And if you think that, you can make Map performance faster by making a primitive as a key, there is a library called FastUtil which contains a Map implementation with int type as a key.

Because of this, it is much faster than Hashmap

Group list by values

values = set(map(lambda x:x[1], mylist))
newlist = [[y[0] for y in mylist if y[1]==x] for x in values]

How to run test methods in specific order in JUnit4?

See my solution here: "Junit and java 7."

In this article I describe how to run junit tests in order - "just as in your source code". Tests will be run, in order as your test methods appears in class file.

But as Pascal Thivent said, this is not a good practise.

What is the id( ) function used for?

Your post asks several questions:

What is the number returned from the function?

It is "an integer (or long integer) which is guaranteed to be unique and constant for this object during its lifetime." (Python Standard Library - Built-in Functions) A unique number. Nothing more, and nothing less. Think of it as a social-security number or employee id number for Python objects.

Is it the same with memory addresses in C?

Conceptually, yes, in that they are both guaranteed to be unique in their universe during their lifetime. And in one particular implementation of Python, it actually is the memory address of the corresponding C object.

If yes, why doesn't the number increase instantly by the size of the data type (I assume that it would be int)?

Because a list is not an array, and a list element is a reference, not an object.

When do we really use id( ) function?

Hardly ever. id() (or its equivalent) is used in the is operator.

Table with 100% width with equal size columns

<table width="400px">
  <td width="100px"></td>
  <td width="100px"></td>
  <td width="100px"></td>
  <td width="100px"></td>

For variable number of columns use %

<table width="100%">
  <td width="(100/x)%"></td>

where 'x' is number of columns

Should I use SVN or Git?

SVN is one repo and lots of clients. Git is a repo with lots of client repos, each with a user. It's decentralised to a point where people can track their own edits locally without having to push things to an external server.

SVN is designed to be more central where Git is based on each user having their own Git repo and those repos push changes back up into a central one. For that reason, Git gives individuals better local version control.

Meanwhile you have the choice between TortoiseGit, GitExtensions (and if you host your "central" git-repository on github, their own client – GitHub for Windows).

If you're looking on getting out of SVN, you might want to evaluate Bazaar for a bit. It's one of the next generation of version control systems that have this distributed element. It isn't POSIX dependant like git so there are native Windows builds and it has some powerful open source brands backing it.

But you might not even need these sorts of features yet. Have a look at the features, advantages and disadvantages of the distributed VCSes. If you need more than SVN offers, consider one. If you don't, you might want to stick with SVN's (currently) superior desktop integration.

Is it possible to have multiple statements in a python lambda expression?

A Hacky way to combine multiple statements into a single statement in python is to use the "and" keyword as a short-circuit operator. Then you can use this single statement directly as part of the lambda expression.

This is similar to using "&&" as the short-circuit operator in shell languages such as bash.

Also note: You can always fix a function statement to return a true value by wrapping the function.


def p2(*args):
    return 1 # a true value

junky = lambda x, y: p2('hi') and p2('there') and p2(x) and p2(y)

junky("a", "b")

On second thought, its probably better to use 'or' instead of 'and' since many functions return '0' or None on success. Then you can get rid of the wrapper function in the above example:

junky = lambda x, y: print('hi') or print('there') or print(x) or print(y)

junky("a", "b")

'and' operate will evaluate the expressions until it gets to the first zero return value. after which it short-circuits. 1 and 1 and 0 and 1 evaluates: 1 and 1 and 0, and drops 1

'or' operate will evaluate the expressions until it gets to the first non-zero return value. after which it short-circuits.

0 or 0 or 1 or 0 evaluates 0 or 0 or 1, and drops 0

Xcode 5.1 - No architectures to compile for (ONLY_ACTIVE_ARCH=YES, active arch=x86_64, VALID_ARCHS=i386)

I solved this problem using @Kjuly's answer and the specific line:

"The reason failed to build might be that, the project does not support the architecture of the device you connected."

With Xcode loaded it automatically set my iPad app to iPad Air

enter image description here

This caused the dependancy analysis error.

Changing the device type immediately solved the issue:

enter image description here

I don't know why this works but this is a very quick answer which saved me a lot of fiddling around in the background and instantly got the app working to test. I would never have thought that this could be a thing and something so simple would fix it but in this case it did.

Get JavaScript object from array of objects by value of property

How about using _.find(collection, [predicate=_.identity], [fromIndex=0]) of lo-dash to get object from array of objects by object property value. You could do something like this:

var o = _.find(jsObjects, {'b': 6});


collection (Array|Object): The collection to inspect.
[predicate=_.identity] (Function): The function invoked per iteration.
[fromIndex=0] (number): The index to search from.


(*): Returns the matched element (in your case, {a: 5, b: 6}), else undefined.

In terms of performance, _.find() is faster as it only pulls the first object with property {'b': 6}, on the other hand, if suppose your array contains multiple objects with matching set of properties (key:value), then you should consider using _.filter() method. So in your case, as your array has a single object with this property, I would use _.find().

How can I get this ASP.NET MVC SelectList to work?

the value selected in the model takes advantage instead of the default item. (I agree I didn't read all posts)

How to SUM two fields within an SQL query

The sum function only gets the total of a column. In order to sum two values from different columns, convert the values to int and add them up using the +-Operator

Select (convert(int, col1)+convert(int, col2)) as summed from tbl1

Hope that helps.

Why do 64-bit DLLs go to System32 and 32-bit DLLs to SysWoW64 on 64-bit Windows?

Ran into the same issue and researched this for a few minutes.

I was taught to use Windows 3.1 and DOS, remember those days? Shortly after I worked with Macintosh computers strictly for some time, then began to sway back to Windows after buying a x64-bit machine.

There are actual reasons behind these changes (some would say historical significance), that are necessary for programmers to continue their work.

Most of the changes are mentioned above:

  • Program Files vs Program Files (x86)

    In the beginning the 16/86bit files were written on, '86' Intel processors.

  • System32 really means System64 (on 64-bit Windows)

    When developers first started working with Windows7, there were several compatibility issues where other applications where stored.

  • SysWOW64 really means SysWOW32

    Essentially, in plain english, it means 'Windows on Windows within a 64-bit machine'. Each folder is indicating where the DLLs are located for applications it they wish to use them.

Here are two links with all the basic info you need:

Hope this clears things up!

Class has no initializers Swift

Not a specific answer to your question but I had got this error when I hadn't set an initial value for an enum while declaring it as a property. I assigned a initial value to the enum to resolve this error. Posting here as it might help someone.

TortoiseSVN Error: "OPTIONS of 'https://...' could not connect to server (...)"

This was driving me nuts and I solved it today. I'm posting in this old thread because I arrived here several times while searching for a solution. I hope it helps someone. For me, I checked svn-settings --> network --> Edit Subversion server file and found that there were some uncommented lines at the end:

http-proxy-host = 
ssl-trust-default-ca = no
http-proxy-username = 
http-proxy-password = 

that differed from my co-workers. Once I comment these, it started working again.

Java: How to set Precision for double value?

You can try BigDecimal for this purpose

Double toBeTruncated = new Double("3.5789055");

Double truncatedDouble = BigDecimal.valueOf(toBeTruncated)
    .setScale(3, RoundingMode.HALF_UP)

How do I remove all .pyc files from a project?

Add to your ~/.bashrc:

pyclean () {
        find . -type f -name "*.py[co]" -delete
        find . -type d -name "__pycache__" -delete

This removes all .pyc and .pyo files, and __pycache__ directories. It's also very fast.

Usage is simply:

$ cd /path/to/directory
$ pyclean

Math operations from string

If you want to do it safely, you may want to use

from this answer: Python "safe" eval (string to bool/int/float/None/string)

It might not do math, but you could parse the math operators and then operate on safely evaluated terms.

Regular expression - starting and ending with a letter, accepting only letters, numbers and _

seeing how the rules are fairly complicated, I'd suggest the following:


match the whole string and capture intermediate characters. Then either with the string functions or the following regex:


check if the captured part has two underscores in a row. For example in Python it would look like this:

>>> import re
>>> def valid(s):
    match = re.match(r'^[a-z](\w*)[a-z0-9]$', s, re.I)
    if match is not None:
        return'__') == 0
    return False

Recursively look for files with a specific extension

find $directory -type f -name "*.in"

is a bit shorter than that whole thing (and safer - deals with whitespace in filenames and directory names).

Your script is probably failing for entries that don't have a . in their name, making $extension empty.

Finding length of char array

You can try this:

   char tab[7]={'a','b','t','u','a','y','t'};

Adding and reading from a Config file

  1. Add an Application Configuration File item to your project (Right -Click Project > Add item). This will create a file called app.config in your project.

  2. Edit the file by adding entries like <add key="keyname" value="someValue" /> within the <appSettings> tag.

  3. Add a reference to the System.Configuration dll, and reference the items in the config using code like ConfigurationManager.AppSettings["keyname"].

How do I serialize a Python dictionary into a string, and then back to a dictionary?

If you are trying to only serialize then pprint may also be a good option. It requires the object to be serialized and a file stream.

Here's some code:

from pprint import pprint
my_dict = {1:'a',2:'b'}
with open('test_results.txt','wb') as f:

I am not sure if we can deserialize easily. I was using json to serialize and deserialze earlier which works correctly in most cases.

f.write(json.dumps(my_dict, sort_keys = True, indent = 2, ensure_ascii=True))

However, in one particular case, there were some errors writing non-unicode data to json.

Jquery Value match Regex

Change it to this:

var email = /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i;

This is a regular expression literal that is passed the i flag which means to be case insensitive.

Keep in mind that email address validation is hard (there is a 4 or 5 page regular expression at the end of Mastering Regular Expressions demonstrating this) and your expression certainly will not capture all valid e-mail addresses.

apache ProxyPass: how to preserve original IP address

If you have the capability to do so, I would recommend using either mod-jk or mod-proxy-ajp to pass requests from Apache to JBoss. The AJP protocol is much more efficient compared to using HTTP proxy requests and as a benefit, JBoss will see the request as coming from the original client and not Apache.

How to add style from code behind?

Try this:

Html Markup

<asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl="#">HyperLink</asp:HyperLink>


using System.Drawing;
using System.Web.UI;
using System.Web.UI.WebControls;

protected void Page_Load(object sender, EventArgs e)
    Style style = new Style();
    style.ForeColor = Color.Green;
    this.Page.Header.StyleSheet.CreateStyleRule(style, this, "#" + HyperLink1.ClientID + ":hover");

COPYing a file in a Dockerfile, no such file or directory?

The COPY instruction in the Dockerfile copies the files in src to the dest folder. Looks like you are either missing the file1, file2 and file3 or trying to build the Dockerfile from the wrong folder.

Refer Dockerfile Doc

Also the command for building the Dockerfile should be something like.

cd into/the/folder/
docker build -t sometagname .

Convert Linq Query Result to Dictionary

Try the following

Dictionary<int, DateTime> existingItems = 
    (from ObjType ot in TableObj).ToDictionary(x => x.Key);

Or the fully fledged type inferenced version

var existingItems = TableObj.ToDictionary(x => x.Key);

How to get the real and total length of char * (char array)?

Legit question. I personally think people confuse pointers with arrays as a result of character pointers (char*), which serve almost the same purpose as character arrays (char __[X]). This means that pointers and arrays are not the same, so pointers of course don't contain a specific size, only an address if I could say so. But nonetheless you can try something similar to strlen.

int ssize(const char* s)
    for (int i = 0; ; i++)
        if (s[i] == 0)
            return i;

    return 0;

Axios having CORS issue

CORS issue can be simply resolved by following this:

Create a new shortcut of Google Chrome(update browser installation path accordingly) with following value:

"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --disable-web-security --user-data-dir="D:\chrome\temp"

Javascript array search and remove string?


You need to find the location of what you're looking for with .indexOf() then remove it with .splice()

function remove(arr, what) {
    var found = arr.indexOf(what);

    while (found !== -1) {
        arr.splice(found, 1);
        found = arr.indexOf(what);

var array = new Array();
remove(array, 'B');

This will take care of all occurrences.

Why is there no ForEach extension method on IEnumerable?

If you have F# (which will be in the next version of .NET), you can use

Seq.iter doSomething myIEnumerable

Paritition array into N chunks with Numpy

I believe that you're looking for numpy.split or possibly numpy.array_split if the number of sections doesn't need to divide the size of the array properly.

How to get ASCII value of string in C#

If you want the charcode for each character in the string, you could do something like this:

char[] chars = "9quali52ty3".ToCharArray();

Rename column SQL Server 2008

Alternatively to SQL, you can do this in Microsoft SQL Server Management Studio. Here are a few quick ways using the GUI:

First Way

Slow double-click on the column. The column name will become an editable text box.

Second Way

Right click on column and choose Rename from the context menu.

For example:

To Rename column name

Third Way

This way is preferable for when you need to rename multiple columns in one go.

  1. Right-click on the table that contains the column that needs renaming.
  2. Click Design.
  3. In the table design panel, click and edit the textbox of the column name you want to alter.

For example: MSSMS Table Design Example

NOTE: I know OP specifically asked for SQL solution, thought this might help others :)

How to make the division of 2 ints produce a float instead of another int?

You can cast even just one of them, but for consistency you may want to explicitly cast both so something like v = (float)s / (float)t should work.

How to use Simple Ajax Beginform in MVC 4?

All This Work :)


  public partial class ClientMessage
        public int IdCon { get; set; } 
        public string Name { get; set; }
        public string Email { get; set; }  


   public class TestAjaxBeginFormController : Controller{  

 projectNameEntities db = new projectNameEntities();

        public ActionResult Index(){  
            return View();

        public ActionResult GetClientMessages(ClientMessage Vm) {
            var model = db.ClientMessages.Where(x => x.Name.Contains(Vm.Name));
            return PartialView("_PartialView", model);

View index.cshtml

@model  projectName.Models.ClientMessage 
    Layout = null;

<script src="~/Scripts/jquery-1.9.1.js"></script>
<script src="~/Scripts/jquery.unobtrusive-ajax.js"></script>
    //\\\\\\\ JS  retrun message SucccessPost or FailPost
    function SuccessMessage() {
        alert("Succcess Post");
    function FailMessage() {
        alert("Fail Post");

<h1>Page Index</h1> 

@using (Ajax.BeginForm("GetClientMessages", "TestAjaxBeginForm", null , new AjaxOptions
    HttpMethod = "POST",
    OnSuccess = "SuccessMessage",
    OnFailure = "FailMessage" ,
    UpdateTargetId = "resultTarget"  
}, new { id = "MyNewNameId" })) // set new Id name for  Form

    @Html.EditorFor(x => x.Name) 
     <input type="submit" value="Search" /> 


<div id="resultTarget">  </div>

View _PartialView.cshtml

@model  IEnumerable<projectName.Models.ClientMessage >

@foreach (var item in Model) { 

        <td>@Html.DisplayFor(modelItem => item.IdCon)</td>
        <td>@Html.DisplayFor(modelItem => item.Name)</td>
        <td>@Html.DisplayFor(modelItem => item.Email)</td>



How to get text from EditText?

Put this in your MainActivity:

    public EditText bizname, storeno, rcpt, item, price, tax, total;
    public Button click, click2;
    int contentView;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );
        setContentView( R.layout.main_activity );
        bizname = (EditText) findViewById( );
        item = (EditText) findViewById( );
        price = (EditText) findViewById( );
        tax = (EditText) findViewById( );
        total = (EditText) findViewById( );
        click = (Button) findViewById( );

Put this under a button or something

public void clickBusiness(View view) {
    checkPermsOfStorage( this );

    bizname = (EditText) findViewById( );
    item = (EditText) findViewById( );
    price = (EditText) findViewById( );
    tax = (EditText) findViewById( );
    total = (EditText) findViewById( );
    String x = ("\nItem/Price: " + item.getText() + price.getText() + "\nTax/Total" + tax.getText() + total.getText());
    Toast.makeText( this, x, Toast.LENGTH_SHORT ).show();
    try {
        String vv = tax.getText().toString();
        System.console().printf( "%s", vv );
        //new XMLDivisionWriter(getString(R.string.SDDoc) + "/tax_div_business.xml");
    } catch (ReflectiveOperationException e) {

There! The debate is settled!