Tutorial by Examples: nf

In all versions of Python, we can represent infinity and NaN ("not a number") as follows: pos_inf = float('inf') # positive infinity neg_inf = float('-inf') # negative infinity not_a_num = float('nan') # NaN ("not a number") In Python 3.5 and higher, we can also us...

models.py : from __future__ import unicode_literals from django.db import models from django.contrib.auth.models import ( AbstractBaseUser, BaseUserManager, PermissionsMixin) from django.utils import timezone from django.utils.translation import ugettext_lazy as _ class UserManage...

When implementing more than one interface that have methods of the same name that include default implementations, it is ambiguous to the compiler which implementation should be used. In the case of a conflict, the developer must override the conflicting method and provide a custom implementation. ...

In your config\services.php you can add the following code 'facebook' => [ 'client_id' => 'your-facebook-app-id', 'client_secret' => 'your-facebook-app-secret', 'redirect' => 'http://your-callback-url', ], You'll also need to add the Provider to your config\app.php L...

To get all the information for a container you can run: docker inspect <container>

You can get an specific information from a container by running: docker inspect -f '<format>' <container> For instance, you can get the Network Settings by running: docker inspect -f '{{ .NetworkSettings }}' <container> You can also get just the IP address: docker inspect ...

All these are shell commands. docker-machine env to get the current default docker-machine configuration eval $(docker-machine env) to get the current docker-machine configuration and set the current shell environment up to use this docker-machine with . If your shell is set up to use a proxy, yo...

Selenium Grid Node configuration resides on the Node itself and holds the information about network configuration and Node capabilities. The configuration can be applied in various ways: Default Configuration JSON Configuration Command line Configuration JSON Configuration The node configur...

This method is called by var_dump() when dumping an object to get the properties that should be shown. If the method isn't defined on an object, then all public, protected and private properties will be shown. — PHP Manual class DeepThought { public function __debugInfo() { return...

In this approach, the single is accessed via the static method: Singleton.getInstance(); To enforce only one instance of the singleton, a private static variable retains the instance, while any additional attempts to instantiate an instance are enforced within the constructor. package { publ...

Travis CI has CMake 2.8.7 pre-installed. A minimal .travis.yml script for an out-of source build language: cpp compiler: - gcc before_script: # create a build folder for the out-of-source build - mkdir build # switch to build directory - cd build # run cmake; here we assume...

The CMake version preinstalled on Travis is very old. You can use the official Linux binaries to build with a newer version. Here is an example .travis.yml: language: cpp compiler: - gcc # the install step will take care of deploying a newer cmake version install: # first we creat...

public class LogActionFilter : ActionFilterAttribute { public override void OnActionExecuting(ActionExecutingContext filterContext) { Log("OnActionExecuting", filterContext.RouteData); } public override void OnActionExecuted(ActionExecute...

Note that you cannot overload a function based on its return type. For example: // WRONG CODE std::string getValue() { return "hello"; } int getValue() { return 0; } int x = getValue(); This will cause a compilation error as the compiler will not be able to work out wh...

Since C# 6.0 exceptions can be filtered using the when operator. This is similar to using a simple if but does not unwind the stack if the condition inside the when is not met. Example try { // ... } catch (Exception e) when (e.InnerException != null) // Any condition can go in here. { ...

SRXMPPDemo Download the example and all the classes here - https://github.com/SahebRoy92/SRXMPPDemo A demo on XMPP in Objective C, with various simple and complex features implemented in it. All the features of XMPP is done by "in band" xmpp functions. Few features this project contains...

We write custom action filters for various reasons. We may have a custom action filter for logging, or for saving data to database before any action execution. We could also have one for fetching data from the database and setting it as the global values of the application. To create a custom actio...

application-name Giving the name of the Web application that the page represents. <meta name="application-name" content="OpenStreetMap"> If it’s not a Web application, the application-name meta tag must not be used. author Set the author of the page: <meta name=&...

iex(1)> i :ok Term :ok Data type Atom Reference modules Atom iex(2)> x = "mystring" "mystring" iex(3)> i x Term "mystring" Data type BitString Byte size 8 Description This is a string: a UTF-8 encoded binary. It's printed surround...

You can use subqueries to define a temporary table and use it in the FROM clause of an "outer" query. SELECT * FROM (SELECT city, temp_hi - temp_lo AS temp_var FROM weather) AS w WHERE temp_var > 20; The above finds cities from the weather table whose daily temperature variation i...