Tutorial by Examples: an

with q command we could simplify a lot of tedious work in vim. example 1. generate array sequence (1 to 20). STEP 1. press i to enter insert mode, input 1 1 STEP 2. Record following action: "append the last number to the next line, and increment the number" type esc to exit input...

First of all you need to have IIS (Internet Information Services) installed and running on your machine; IIS isn't available by default, you have to add the characteristic from Control Panel -> Programs -> Windows Characteristics. Download the PHP version you like from http://windows.php.ne...

For example you want to use surfaceView in ng2-nativescript. As we don't have surfaceView in nativescript we should use placeholder. first we should import the requirements: import {Component} from "@angular/core"; import placeholder = require("ui/placeholder"); let applicat...

app.component.ts: import {Component,OnInit} from "@angular/core"; import placeholder = require("ui/placeholder"); let application= require("application"); @Component({ selector: "my-app", templateUrl: "app.component.html", }) export...

Below are examples of generating 5 random numbers using various probability distributions. Uniform distribution between 0 and 10 runif(5, min=0, max=10) [1] 2.1724399 8.9209930 6.1969249 9.3303321 2.4054102 Normal distribution with 0 mean and standard deviation of 1 rnorm(5, mean=0, sd=1) [1...

The -Command parameter is used to specify commands to be executed on launch. It supports multiple data inputs. -Command <string> You can specify commands to executed on launch as a string. Multiple semicolon ;-separated statements may be executed. >PowerShell.exe -Command "(Get-Date...

public static async Task<TResult> GetAnsync<TResult>(this Uri uri) { using (var client = new HttpClient()) { var message = await client.GetAsync(uri); if (!message.IsSuccessStatusCode) throw new Exception(); return message.ReadAsAsyn...

To use default values with **kwargs def fun(**kwargs): print kwargs.get('value', 0) fun() # print 0 fun(value=1) # print 1

from py2neo import authenticate, Graph, Node, Relationship authenticate("localhost:7474", "neo4j", "<pass>") graph = Graph() You have to make sure your Neo4j Database exists at localhost:7474 with the appropriate credentials. the graph object is your interfa...

Installation Installation of Log4j2 is as simple as putting log4j2 jar in application classpath. Though you might want to customize logs output through additional config file Configuration maven To add log4j to project in maven, add it's dependency: In pom.xml add following dependency: <dep...

An F() object represents the value of a model field or annotated column. It makes it possible to refer to model field values and perform database operations using them without actually having to pull them out of the database into Python memory. - F() expressions It is appropriate to use F() obj...

Supposing you have setup a django project, and the settings file is in an app named main, this is how you initialize your code import os, sys # Setup environ sys.path.append(os.getcwd()) os.environ.setdefault("DJANGO_SETTINGS_MODULE", "main.settings") # Setup django imp...

When we query our data, we often need more than one filter to get the exact data set we are looking for. In SQL, we handle this with AND and OR clauses. We can achieve the same thing with collections. To add an AND clause to your query, just simply add another method call. This will append the seco...

This uses the SwiftyDropbox library to upload a file from a NSFileHandle to the Dropbox account using upload sessions, handling every error case: import UIKit import SwiftyDropbox class ViewController: UIViewController { // filled in later in doUpload: var fileHandle : NSFileHandle?...

Use the double negation syntax to check for truthiness of values. All values correspond to a boolean, irrespective of their type. irb(main):001:0> !!1234 => true irb(main):002:0> !!"Hello, world!" (irb):2: warning: string literal in condition => true irb(main):003:0> !...

You do not need to use double negation in if-else statements. if 'hello' puts 'hey!' else puts 'bye!' end The above code prints 'hey!' on the screen.

If you can say “YAGNI” (You ain’t gonna need it) about a feature, you better not implement it. There can be a lot of development time saved through focussing onto simplicity. Implementing such features anyway can lead to problems: Problems Overengineering If a product is more complicated than it...

Creating the event object Swift var event = EKEvent(eventStore: eventStore) Objective-C EKEvent *event = [EKEvent initWithEventStore:eventStore]; Setting related calendar, title and dates Swift event.calendar = calendar event.title = "Event Title" event.startDate = startDate /...

In Symfony, the built-in ChoiceType (and EntityType or DocumentType extending it), basicaly work with a constant choice list. If you want to make it work with ajax calls, you have to change them to accept any sumitted extra choices. How to start with an empty choice list ? When you build your...

This is an example to show how to change the allowed choices on a subCategory select field depending on the value of the category select field. To do that you have to make your subCategory choices dynamical for both client and server side. 1. Make the form dynamic on the client side for display / ...