Tutorial by Examples: od

There is a useful package in Python - chardet, which helps to detect the encoding used in your file. Actually there is no program that can say with 100% confidence which encoding was used - that's why chardet gives the encoding with the highest probability the file was encoded with. Chardet can dete...

Django's built-in User model is not always appropiate for some kinds of projects. On some sites it might make more sense to use an email address instead of a username for instance. You can override the default User model adding your customized User model to the AUTH_USER_MODEL setting, in your proj...

Your code will not work in projects where you reference the User model (and where the AUTH_USER_MODEL setting has been changed) directly. For example: if you want to create Post model for a blog with a customized User model, you should specify the custom User model like this: from django.conf impo...

JSON_MODIFY function uses JSON text as input parameter, and modifies a value on the specified path using third argument: declare @json nvarchar(4000) = N'{"Id":1,"Name":"Toy Car","Price":34.99}' set @json = JSON_MODIFY(@json, '$.Price', 39.99) print @json -...

The header ctype.h is a part of the standard C library. It provides functions for classifying and converting characters. All of these functions take one parameter, an int that must be either EOF or representable as an unsigned char. The names of the classifying functions are prefixed with 'is'. Ea...

Character modifying functions include converting characters to upper or lower case characters, converting numbers to formatted numbers, performing character manipulation, etc. The lower(char) function converts the given character parameter to be lower-cased characters. SELECT customer_id, lower(cu...

A linked list is either: the empty list, represented by None, or a node that contains a cargo object and a reference to a linked list. #! /usr/bin/env python class Node: def __init__(self, cargo=None, next=None): self.car = cargo self.cdr = next d...

Consider the following example: public class Example { public int a, b, c, d; public void doIt() { a = b + 1; c = d + 1; } } If this class is used is a single-threaded application, then the observable behavior will be exactly as you would expect. For instan...

When a new documentation tag is created, StackOverflow automatically generates an introductory topic, acting as a placeholder for the first actual topic. The introductory topic contains placeholder texts and pointers to point contributors in the right directions for helping expanding on the new doc...

// Set up Express var express = require('express'); var app = express(); /* Serve from the absolute path of the directory that you want to serve with a */ virtual path prefix app.use('/static', express.static(__dirname + '/public')); // Start Express server app.listen(3030);

A lot of example code posted on StackOverflow includes snippets like this: if ("A".equals(someString)) { // do something } This does "prevent" or "avoid" a possible NullPointerException in the case that someString is null. Furthermore, it is arguable that ...

All programming languages allow us to assign values to variables. Usually, a value is assigned to variable, standing on left side. The prototype of the overall assignment operations in any contemporary programming language looks like this: left_operand assignment_operand right_operand instructions_...

Though Go supports ++ and -- operators and the behaviour is found to be almost similar to c/c++, variables with such operators cannot be passed as argument to function. package main import ( "fmt" ) func abcd(a int, b int) { fmt.Println(a," &...

Go to the Microsoft link for the OpenXML SDK download. Click the red download button. On the next screen click the box next to OpenXMLSDKToolV25.msi and click next to begin the download. Once the download is complete, launch the OpenXMLSDKToolV25.msi and follow the instructions on the screen. Th...

productFlavors { // Define separate dev and prod product flavors. dev { // dev utilizes minSDKVersion = 21 to allow the Android gradle plugin // to pre-dex each module and produce an APK that can be tested on // Android Lollipop without time c...

Swarm Mode Node Availability: Active means that the scheduler can assign tasks to a node. Pause means the scheduler doesn’t assign new tasks to the node, but existing tasks remain running. Drain means the scheduler doesn’t assign new tasks to the node. The scheduler shuts down any existing ta...

To promote a node or set of nodes, run docker node promote from a manager node: docker node promote node-3 node-2 Node node-3 promoted to a manager in the swarm. Node node-2 promoted to a manager in the swarm. To demote a node or set of nodes, run docker node demote from a manager node: doc...

First, ensure you have installed mongodb and express via npm. Then, in a file conventionally titled db.js, use the following code: var MongoClient = require('mongodb').MongoClient var state = { db: null, } exports.connect = function(url, done) { if (state.db) return done() M...

Why annotations? Generally we use annotation to facilitate the development and to make the code more clear and clean. What are annotations? Java 5 annotations provide standardization of metadata in a general goal. This metadata associated with Java features can be exploited in the compilation or ...

This example uses Angular 2.0.0 Final Release registration-form.component.ts import { FormGroup, FormControl, FormBuilder, Validators } from '@angular/forms'; @Component({ templateUrl: "./registration-form.html" }) export class ExampleComponent { ...