Tutorial by Examples: g

from module.submodule import function This imports function from module.submodule.

from datetime import timedelta from django.utils import timezone from psycopg2.extras import DateTimeTZRange # To create a "period" object we will use psycopg2's DateTimeTZRange # which takes the two datetime bounds as arguments period_start = timezone.now() period_end = period_s...

Use assert_raise to test if an exception was raised. assert_raise takes in an Exception and a function to be executed. test "invalid block size" do assert_raise(MerkleTree.ArgumentError, (fn() -> MerkleTree.new ["a", "b", "c"] end)) end Wrap a...

Use defdelegate to define functions that delegate to functions of the same name defined in another module: defmodule Math do defdelegate pi, to: :math end iex> Math.pi 3.141592653589793

Hierarchy - LinearLayout(horizontal) - ImageView - LinearLayout(vertical) - TextView - TextView Code LinearLayout rootView = new LinearLayout(context); rootView.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT)); rootView.s...

public class ExampleActivity extends Activity { private final static String EXAMPLE_ARG = "example_arg"; private int mArg; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layou...

With the appropriate storage backend running a new titan graph can be initialised via: graph = TitanFactory.open("config.properties"); Wehere config.properties defines several configurations relevant to the storage backend. Titan provides some sample configs in its downloadable package...

// Uses Windows authentication. Replace the Trusted_Connection parameter with // User Id=...;Password=...; to use SQL Server authentication instead. You may // want to find the appropriate connection string for your server. string connectionString = @"Server=myServer\myInstance;Database=myDa...

#!/usr/bin/env perl use strict; use warnings 'all'; use XML::Twig; my $twig = XML::Twig->parse( \*DATA ); #we can use the 'root' method to find the root of the XML. my $root = $twig->root; #first_child finds the first child element matching a value. my $title = $root->firs...

The default gnuplot command plot (also only p) plot dataset with columns, of the form of the data_set.dat file below. # Prototype of a gnuplot data set # data_set.dat # X - X^2 - 2*X - Random 0 0 0 5 1 1 2 15 1.4142 2 2.8284 1 2 ...

Android $ react-native log-android iOS $ react-native log-ios

To initialize react-native init MyAwesomeProject To initialize with a specific version of React Native react-native init --version="0.36.0" MyAwesomeProject To Run for Android cd MyAwesomeProject react-native run-android To Run for iOS cd MyAwesomeProject react-native run-io...

Hints to the compiler that access to an object should be as fast as possible. Whether the compiler actually uses the hint is implementation-defined; it may simply treat it as equivalent to auto. The only property that is definitively different for all objects that are declared with register is that...

$ react-native start On latest version of React Native, no need to run the packager. It will run automatically. By default this starts the server at port 8081. To specify which port the server is on $ react-native start --port PORTNUMBER

The reduce method reduces the collection to a single value, passing the result of each iteration into the subsequent iteration. Please see reduce method. The reduce method loops through each item with a collection and produces new result to the next iteration. Each result from the last iteration ...

The <see> tag can be used to link to another class. It contains the cref member which should contain the name of the class that is to be referenced. Visual Studio will provide Intellsense when writing this tag and such references will be processed when renaming the referenced class, too. /// ...

You can use the System.IO.File.ReadAllText function to read the entire contents of a file into a string. string text = System.IO.File.ReadAllText(@"C:\MyFolder\MyTextFile.txt"); You can also read a file as an array of lines using the System.IO.File.ReadAllLines function: string[] line...

The System.IO.StreamWriter class: Implements a TextWriter for writing characters to a stream in a particular encoding. Using the WriteLine method, you can write content line-by-line to a file. Notice the use of the using keyword which makes sure the StreamWriter object is disposed as soon as ...

You can use the System.IO.File.WriteAllText function to write a string to a file. string text = "String that will be stored in the file"; System.IO.File.WriteAllText(@"C:\MyFolder\OutputFile.txt", text); You can also use the System.IO.File.WriteAllLines function which receiv...

The System.String class supports a number of methods to convert between uppercase and lowercase characters in a string. System.String.ToLowerInvariant is used to return a String object converted to lowercase. System.String.ToUpperInvariant is used to return a String object converted to upper...