Tutorial by Examples: e

Deque operations

A deque is a double-ended queue. class Deque: def __init__(self): self.items = [] def isEmpty(self): return self.items == [] def addFront(self, item): self.items.append(item) def addRear(self, item): self.items.insert(0,item) def removeFront(self): return self....

Python Language • Python speed of program

Set operations

Operation : Average Case (assumes parameters generated randomly) : Worst case x in s : O(1) Difference s - t : O(len(s)) Intersection s&t : O(min(len(s), len(t))) : O(len(s) * len(t) Multiple intersection s1&s2&s3&...&sn : : (n-1) * O(l) where l is max(len(s1),...,len(sn)) s...

Python Language • Python speed of program

One or two parameters in callback—error handling in d3.request()

When using d3.request() or one of the convenience constructors (d3.json, d3.csv, d3.tsv, d3.html and d3.xml) there are many sources for error. There may be problems with the issued request or its response due to network errors, or the parsing might fail if the content is not well-formed. Within the...

d3.js • Using D3 with JSON and CSV

Splitting Strings using CROSS APPLY (Oracle 12c)

Sample Data: CREATE TABLE table_name ( id, list ) AS SELECT 1, 'a,b,c,d' FROM DUAL UNION ALL -- Multiple items in the list SELECT 2, 'e' FROM DUAL UNION ALL -- Single item in the list SELECT 3, NULL FROM DUAL UNION ALL -- NULL list SELECT 4, 'f,,g' FROM DUAL; -- NULL item...

Oracle Database • Splitting Delimited Strings

Basic usage

In config.ini: [DEFAULT] debug = True name = Test password = password [FILES] path = /path/to/file In Python: from ConfigParser import ConfigParser config = ConfigParser() #Load configuration file config.read("config.ini") # Access the key "debug" in "DEF...

Python Language • configparser

Encryption and Decryption using Cryptography (AES)

Decryption Code public static string Decrypt(string cipherText) { if (cipherText == null) return null; byte[] cipherBytes = Convert.FromBase64String(cipherText); using (Aes encryptor = Aes.Create()) { Rfc2898DeriveBytes pdb = ...

.NET Framework • Encryption / Cryptography

Getting details of Linux kernel.

We can use command uname with various options to get complete details of running kernel. uname -a Linux df1-ws-5084 4.4.0-64-generic #85-Ubuntu SMP Mon Feb 20 11:50:30 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux As per man page here few more options Usage: uname [OPTION]... Print certain system inf...

GNU/Linux • Getting information on a running Linux kernel

Replacing fragments with ajax

If you want to replace parts of your website, ajax is an easy way to do it. The website.html where you want to replace the content based on the selected value: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"> ...

thymeleaf • Getting started with thymeleaf

Types of Validations

Let's initially understand basic types of custom validators: Inline Validator Standalone Validator Inline Validator: It is the type of the validator we create inside the class which is basically a method we define just like other methods but with extra parameters which is passed in by Yii2. ...

yii2 • Custom Validations

Access to Request in a Twig or PHP template.

In Twig template, Request object is available at {{ app.request }} When you want display request method in Twig, try this: <p>Request method: {{ app.request.method }}</p> In PHP template <p>Request method: <?php echo $app->getRequest()->getMethod() ?></p>...

symfony2 • Request

Grouping a few input fields

While designing a form, you might like to group a few input fields into a group to help organise the form layout. This can be done by using the tag . Here is an example for using it. For each fieldset, you can set a legend for the set using the tag LEGEND TEXT Example <form> <fieldset...

HTML • Forms

Basic jumbotron with two lines of text and a button

This is a jumbotron with a title, a content and a button. Code <div class="jumbotron"> <h1>Title text</h1> <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec tortor ipsum, convallis sit.</p> <p><a class="btn btn-default&...

twitter-bootstrap • Jumbotron

Observer using IObservable and IObserver (C#)

IObserver<T> and IObservable<T> interfaces can be used to implement observer pattern in .NET IObservable<T> interface represents the class that sends notifications IObserver<T> interface represents the class that receives them public class Stock { private string Sym...

Design patterns • Observer

Adding the "Theme page title" item to the nav bar

Code function add_the_theme_page(){ add_menu_page('Theme page title', 'Theme menu label', 'manage_options', 'theme-options', 'page_content', 'dashicons-book-alt'); } add_action('admin_menu', 'add_the_theme_page'); function page_content(){ echo '<div class="wrap"><h2&...

WordPress • add_menu_page()

Secure your WebApp with Login and Logout

This example is a very simple Spring Boot application. Maven Dependencies At first add the following dependencies to your project. Spring Initializr is recommended when you create a new project. <parent> <groupId>org.springframework.boot</groupId> <artifactId>spr...

thymeleaf • Spring Security and Thymeleaf

Example

First you have to create a file constants.php and it is a good practice to create this file inside app/config/ folder. You can also add constants.php file in compose.json file. Example File: app/config/constants.php Array based constants inside the file: return [ 'CONSTANT' => 'This...

Laravel • Constants