Tutorial by Examples: od

If you want to import a module that doesn't already exist as a built-in module in the Python Standard Library nor as a side-package, you can do this by adding the path to the directory where your module is found to sys.path. This may be useful where multiple python environments exist on a host. im...

First the setup for the example: import datetime as dt from sqlalchemy import Column, Date, Integer, Text, create_engine, inspect from sqlalchemy.orm import sessionmaker from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() Session = sessionmaker() class User(B...

In SQLAlchemy core, the result is RowProxy. In cases where you want an explicit dictionary, you can call dict(row). First the setup for the example: import datetime as dt from sqlalchemy import ( Column, Date, Integer, MetaData, Table, Text, create_engine, select) metadata = MetaData() u...

JSON data can also be read from files. Let's assume we have a file called data.json with the following content: [ { "Name" : "John Doe", "Standard" : 4 }, { "Name" : "Peter Parker", "Standard" : ...

In this code example, the char pointer p is initialized to the address of a string literal. Attempting to modify the string literal has undefined behavior. char *p = "hello world"; p[0] = 'H'; // Undefined behavior However, modifying a mutable array of char directly, or through a poin...

Given a JList like JList myList = new JList(items); the selected items in the list can be modified through the ListSelectionModel of the JList: ListSelectionModel sm = myList.getSelectionModel(); sm.clearSelection(); // clears the selection sm.setSelectionInterval(inde...

Constructor overloading is not available in As3. In order to provide a different way to retrieve an instance of a class, a public static method can be provided to serve as an alternative "constructor". An example for that is flash.geom.Point, which represents a 2D point object. The coor...

When an extension method returns a value that has the same type as its this argument, it can be used to "chain" one or more method calls with a compatible signature. This can be useful for sealed and/or primitive types, and allows the creation of so-called "fluent" APIs if the me...

Prerequisites sudo apt-get install build-essential sudo apt-get install python [optional] sudo apt-get install git Get source and build cd ~ git clone https://github.com/nodejs/node.git OR For the latest LTS Node.js version 6.10.2 cd ~ wget https://nodejs.org/dist/v6.3.0/node-v6.10....

It is very convenient to use extension methods with interfaces as implementation can be stored outside of class and all it takes to add some functionality to class is to decorate class with interface. public interface IInterface { string Do() } public static class ExtensionMethods{ pu...

Method chaining is a programming strategy that simplifies your code and beautifies it. Method chaining is done by ensuring that each method on an object returns the entire object, instead of returning a single element of that object. For example: function Door() { this.height = ''; this.w...

In [1]: df1 = pd.DataFrame({'x': [1, 2, 3], 'y': ['a', 'b', 'c']}) In [2]: df2 = pd.DataFrame({'y': ['b', 'c', 'd'], 'z': [4, 5, 6]}) In [3]: df1 Out[3]: x y 0 1 a 1 2 b 2 3 c In [4]: df2 Out[4]: y z 0 b 4 1 c 5 2 d 6 Inner join: Uses the intersection ...

This is an example of how to use the generic type TFood inside Eat method on the class Animal public interface IFood { void EatenBy(Animal animal); } public class Grass: IFood { public void EatenBy(Animal animal) { Console.WriteLine("Grass was eaten by: {0}",...

iex([email protected])> Node.list [:"[email protected]"]

Start two named nodes in two terminal windows: >iex --name [email protected] iex([email protected])> >iex --name [email protected] iex([email protected])> Connect two nodes by instructing one node to connect: iex([email protected])> Node.connect :"[email protected]" true The two n...

Start a named process on one IP address: $ iex --name [email protected] --cookie chocolate iex([email protected])> Node.ping :"[email protected]" :pong iex([email protected])> Node.list [:"[email protected]"] Start another named process on a different IP address: $ iex ...

Use the HTML or <audio> element to embed video/audio content in a document. The video/audio element contains one or more video/audio sources. To specify a source, use either the src attribute or the <source> element; the browser will choose the most suitable one. Audio tag example: &...

1) BASIC SIMPLE WAY Database-driven applications often need data pre-seeded into the system for testing and demo purposes. To make such data, first create the seeder class ProductTableSeeder use Faker\Factory as Faker; use App\Product; class ProductTableSeeder extends DatabaseSeeder { pub...

Consider this simple class: class SmsUtil { public bool SendMessage(string from, string to, string message, int retryCount, object attachment) { // Some code } } Before C# 3.0 it was: var result = SmsUtil.SendMessage("Mehran", "Maryam", "Hello...

A callback is a method that gets called at specific moments of an object's lifecycle (right before or after creation, deletion, update, validation, saving or loading from the database). For instance, say you have a listing that expires within 30 days of creation. One way to do that is like this: ...