Tutorial by Examples: le

import sympy as sy # Symbols have to be defined before one can use them x = sy.S('x') # Definition of the equation to be solved eq=sy.Eq(x**2 + 2, 6) #Print the solution of the equation print sy.solve(eq) The result printed will be: [-2, 2]

In multiple table UPDATE, it updates rows in each specified tables that satisfy the conditions. Each matching row is updated once, even if it matches the conditions multiple times. In multiple table UPDATE, ORDER BY and LIMIT cannot be used. Syntax for multi table UPDATE is, UPDATE [LOW_PRIORITY]...

By default Controllers, ViewComponents and TagHelpers aren't registered and resolved via the dependency injection container. This results in the inability to do i.e. property injection when using a 3rd party Inversion of Control (IoC) container like AutoFac. In order to make ASP.NET Core MVC resolv...

dispatch_group_t preapreWaitingGroup = dispatch_group_create(); dispatch_group_enter(preapreWaitingGroup); [self doAsynchronousTaskWithComplete:^(id someResults, NSError *error) { // Notify that this task has been completed. dispatch_group_leave(preapreWaitingGroup); }] dispatch...

Configuration Log4j configuration file can be in any of these formats: JSON YAML properties (text file) XML Configuration discovery Log4j will inspect the log4j.configurationFile system property and, if set, will attempt to load the configuration. If no system property is set log4j wil...

For example, we have two environments: CI - Staging and want to add some customizations for each environment. Here I will try to customize server URL, app name. First, we create two targets for 2 environments by duplicating the main target: For each target, we will define a custom macro. Here I ...

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...

Animation to show how selection sort works Below example shows selection sort in ascending order: public class MySelectionSort { public static int[] doSelectionSort(int[] arr){ for (int i = 0; i < arr.length - 1; i++) { int index = i; ...

The advantage of using Apache over the builtin werkzeug server is that Apache is multi-threaded, meaning that multiple connections to the application can be made simultaneously. This is especially useful in applications that make use of XmlHttpRequest (AJAX) on the front-end. /etc/apache2/sites-ava...

To set the environment to Development SET ASPNETCORE_ENVIRONMENT=Development Now running an Asp.Net Core application will be in the defined environment. Note There should be no space before and after the equality sign =. The command prompt should not be closed before running the application b...

The single line comment begins with "//" or "#". When encountered, all text to the right will be ignored by the PHP interpreter. // This is a comment # This is also a comment echo "Hello World!"; // This is also a comment, beginning where we see "//" ...

The <header> element represents introductory content for its nearest ancestor sectioning content or sectioning root element. A <header> typically contains a group of introductory or navigational aids. Note: The header element is not sectioning content; it doesn’t introduce a new secti...

The <footer> element contains the footer part of the page. Here is an example for <footer> element that contain p paragraph tag. <footer> <p>All rights reserved</p> </footer>

from flask import Flask, render_template, redirect, url_for app = Flask(__name__) @app.route('/') def main_page(): return render_template('main.html') @app.route('/main') def go_to_main(): return redirect(url_for('main_page'))

Multiton can be used as a container for singletons. This is Multiton implementation is a combination of Singleton and Pool patterns. This is an example of how common Multiton abstract Pool class can be created: abstract class MultitonPoolAbstract { /** * @var array */ protec...

This pattern can be used to contain a registered Pools of Singletons, each distinguished by unique ID: abstract class MultitonRegistryAbstract { /** * @var array */ protected static $instances = []; /** * @param string $id */ final protected function ...

A pattern rule is indicated by a single % character in the target. The % matches a non-empty string called the stem. The stem is then substituted for every % that appears in the prerequisite list. For example, this rule: %.o: %.c $(CC) $(CFLAGS) -c $< -o $@ Will match any target ending ...

If a target matches multiple pattern rules, make will use the one whose prerequisites exist or can be built. For example: %.o: %.c $(CC) $(CFLAGS) -c $< -o $@ %.o: %.s $(AS) $(ASFLAGS) $< -o $@ Will compile foo.c to foo.o or assemble foo.s to foo.o, depending on which one of foo...

If the target pattern doesn't contain slashes, make will remove the directory part from the target it's trying to build before matching. The directory will then be put in front of the stem. When the stem is used to build the target name and prerequisites, the directory part is stripped from it, the ...

Pattern rules can have multiple targets but, unlike normal rules, the recipe is responsible for making all the targets. For example: debug/%.o release/%.o: %.c $(CC) $(CFLAGS_DEBUG) -c $< -o debug/$*.o $(CC) $(CFLAGS_RELEASE) -c $< -o release/$*.o Is a valid rule, which will buil...