Tutorial by Examples: pre

Plenty has been written about Python's GIL. It can sometimes cause confusion when dealing with multi-threaded (not to be confused with multiprocess) applications. Here's an example: import math from threading import Thread def calc_fact(num): math.factorial(num) num = 600000 t = Threa...

A computed column is computed from an expression that can use other columns in the same table. The expression can be a noncomputed column name, constant, function, and any combination of these connected by one or more operators. Create table with a computed column Create table NetProfit ( Sa...

Detailed instructions on getting wordpress-theming set up or installed. Wordpress is opensource.You can find large set of theme for use free or premium themes.All theme are provide a documentation for install and use. What you have to understand while choose a theme? Wordpress version you are ...

In order to prevent a button from firing multiple times within a short period of time (let's say 2 clicks within 1 second, which may cause serious problems if the flow is not controlled), one can implement a custom SingleClickListener. This ClickListener sets a specific time interval as threshold (...

PrepareForSegue: func prepareForSegue(_ segue:UIStoryboardSegue, sender sender:AnyObject?) Notifies the view controller that a segue is about to be performed Parameters segue: The segue object. sender: The object that initialized the segue. Example in Swift Perform a task if the ident...

To install DevExpress .NET products on your development machine, it is first necessary to obtain the DevExpress .NET Products Installer. You can download it from the http://www.devexpress.com website in one of the following ways, based on the status of your current account. Download the Trial ...

Get Compressed Bitmap from Singleton class: ImageView imageView = (ImageView)findViewById(R.id.imageView); Bitmap bitmap = ImageUtils.getInstant().getCompressedBitmap("Your_Image_Path_Here"); imageView.setImageBitmap(bitmap); ImageUtils.java: public class ImageUtils { public ...

In this example, we are going to create an image picker that previews your picture before uploading. The previewer also supports drag and dropping files into the input. In this example, I am only going to cover uploading single files, but you can tinker a bit to get multi file upload working. image...

An expression template is a compile-time optimization technique used mostly in scientific computing. It's main purpose is to avoid unnecessary temporaries and optimize loop calculations using a single pass (typically when performing operations on numerical aggregates). Expression templates were init...

In order to begin using WebRTC you need to get camera and microphone permission.For that you need following things: adapter.js, you can get it from here A html webpage with a video tag and little bit of js code The adapter.js is a JavaScript shim for WebRTC, maintained by Google with help fro...

int i; int n = 1000000; double area = 0; double h = 1.0 / n; #pragma omp parallel shared(n, h) { double thread_area = 0; // Private / local variable #pragma omp for for (i = 1; i <= n; i++) { double x = h * (i - 0.5); thread_area += (4.0 / (1.0 ...

int i; int n = 1000000; double area = 0; double h = 1.0 / n; #pragma omp parallel for shared(n, h) reduction(+:area) for (i = 1; i <= n; i++) { double x = h * (i - 0.5); area += (4.0 / (1.0 + x*x)); } pi = h * area; In this example, each threads execute a subset of the iteration...

Expression trees represent code in a tree-like data structure, where each node is an expression Expression Trees enables dynamic modification of executable code, the execution of LINQ queries in various databases, and the creation of dynamic queries. You can compile and run code represented by expr...

You can also create an instance of Parse Server, and mount it on a new or existing Express website: var express = require('express'); var ParseServer = require('parse-server').ParseServer; var app = express(); var api = new ParseServer({ databaseURI: 'mongodb://localhost:27017/dev', // Conn...

Some programmers think that it is a good idea to save space by using a null to represent an empty array or collection. While it is true that you can save a small amount of space, the flipside is that it makes your code more complicated, and more fragile. Compare these two versions of a method for ...

Messages can be written with; Write-Verbose "Detailed Message" Write-Information "Information Message" Write-Debug "Debug Message" Write-Progress "Progress Message" Write-Warning "Warning Message" Each of these has a preference variable; $Ve...

Conditions can also be expressions: $myInput = 0 switch($myInput) { # because the result of the expression, 4, # does not equal our input this block should not be run. (2+2) { 'True. 2 +2 = 4' } # because the result of the expression, 0, # does equal our input this ...

C# 7.0 allows throwing as an expression in certain places: class Person { public string Name { get; } public Person(string name) => Name = name ?? throw new ArgumentNullException(nameof(name)); public string GetFirstName() { var parts = Name.Split(' '); ...

C# 7.0 adds accessors, constructors and finalizers to the list of things that can have expression bodies: class Person { private static ConcurrentDictionary<int, string> names = new ConcurrentDictionary<int, string>(); private int id = GetId(); public Person(string n...

Consider the following list comprehension Python 2.x2.7 i = 0 a = [i for i in range(3)] print(i) # Outputs 2 This occurs only in Python 2 due to the fact that the list comprehension “leaks” the loop control variable into the surrounding scope (source). This behavior can lead to hard-to-find...