Tutorial by Examples: st

Use the makemigrations --name <your_migration_name> option to allow naming the migrations(s) instead of using a generated name. python manage.py makemigrations --name <your_migration_name> <app_name>

The encoding to be used for the standard I/O filehandles (STDIN, STDOUT, and STDERR), can be set separately for each handle using binmode: binmode STDIN, ':encoding(utf-8)'; binmode STDOUT, ':utf8'; binmode STDERR, ':utf8'; Note: when reading one would in general prefer :encoding(utf-8) over :...

After successfully installing Xamarin as described in the first example, it's time to launch the first sample application. Step 1: Creating a new Project. In Visual Studio, choose New -> Project -> Visual C# -> Cross-Platform -> Blank App (Xamarin.Forms Portable) Name the app "He...

static and templates folder in the apps may should also contain a folder with the name of app ex. blog this is a convention used to prevent namespace pollution, so we reference the files like /blog/base.html rather than /base.html which provides more clarity about the file we are referencing and pre...

The coordinate systems of Matplotlib come very handy when trying to annotate the plots you make. Sometimes you would like to position text relatively to your data, like when trying to label a specific point. Other times you would maybe like to add a text on top of the figure. This can easily be achi...

A string is a sequence of character literals. To date, strings are supported by all modern programming languages,1 but there is no consensus between language designers on how strings should be classified. As far as programming language design is concerned there are two primary concerns to take into ...

Least squares is a standard approach to problems with more equations than unknowns, also known as overdetermined systems. Consider the four equations: x0 + 2 * x1 + x2 = 4 x0 + x1 + 2 * x2 = 3 2 * x0 + x1 + x2 = 5 x0 + x1 + x2 = 4 We can express this as a matrix multiplication A * x = b: A ...

Use git revert to revert existing commits, especially when those commits have been pushed to a remote repository. It records some new commits to reverse the effect of some earlier commits, which you can push safely without rewriting history. Don't use git push --force unless you wish to bring down ...

Getting zsh zsh is available on many UNIX-like platforms via their built-in package management systems. On the Debian and Ubuntu Linux distributions, zsh is available in the default package repositories and can be installed using: $ sudo apt-get install zsh # or, on newer Ubuntu distributions $ ...

Javassist is a bytecode instrumentation library that allows you to modify bytecode injecting Java code that will be converted to bytecode by Javassist and added to the instrumented class/method at runtime. Lets write the first transformer that actually take an hypothetical class "com.my.to.be....

The following example illustrates how to use CullingGroups to get notifications according to the distance reference point. This script has been simplified for brevity and uses several performance heavy methods. using UnityEngine; using System.Linq; public class CullingGroupBehaviour : Mono...

You can add bounding distances on top of culling point radius. They are in a manner additional trigger conditions outside the culling points' main radius, like "close", "far" or "very far". cullingGroup.SetBoundingDistances(new float[] { 0f, 10f, 100f}); Bounding ...

As a developer, you frequently find yourself dealing with strings that are not created by your own code. These will often be supplied by third party libraries, external systems, or even end users. Validating strings of unclear provenance is considered to be one of the hallmarks of defensive program...

module.exports.routes = { 'GET /foo': 'FooController.index', 'GET /foo/new': 'FooController.new', 'POST /foo/create': 'FooController.create', 'GET /foo/:id/edit': 'FooController.edit', 'PUT /foo/:id/update': 'FooController.update', 'GET /foo/:id': 'FooController.show', ...

module.exports.routes = { // This function will be executed for all http verbs on all urls 'all /*', function (req, res, next) { // Expose the function `fooBar` to all views (via the locals object) res.locals.fooBar = function (arg1) { return 'foobar' + arg1; }; }, };...

Consider using Extension Methods as Functions which wrap other code, here's a great example that uses both a static method and and extension method to wrap the Try Catch construct. Make your code Bullet Proof... using System; using System.Diagnostics; namespace Samples { /// <summary&g...

Structures in Rust are defined using the struct keyword. The most common form of structure consists of a set of named fields: struct Foo { my_bool: bool, my_num: isize, my_string: String, } The above declares a struct with three fields: my_bool, my_num, and my_string, of the type...

Consider the following struct definitions: struct Foo { my_bool: bool, my_num: isize, my_string: String, } struct Bar (bool, isize, String); struct Baz; Constructing new structure values for these types is straightforward: let foo = Foo { my_bool: true, my_num: 42, my_string: ...

To declare methods on a struct (i.e., functions that can be called "on" the struct, or values of that struct type), create an impl block: impl Foo { fn fiddle(&self) { // "self" refers to the value this method is being called on println!("fiddling...

Structures can be made generic over one or more type parameters. These types are given enclosed in <> when referring to the type: struct Gen<T> { x: T, z: isize, } // ... let _: Gen<bool> = Gen{x: true, z: 1}; let _: Gen<isize> = Gen{x: 42, z: 2}; let _: Gen...