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Intersection of Hashes To get the intersection of two hashes, return the shared keys the values of which are equal: hash1 = { :a => 1, :b => 2 } hash2 = { :b => 2, :c => 3 } hash1.select { |k, v| (hash2.include?(k) && hash2[k] == v) } # => { :b => 2 } Union (...

Here is a quick example of using multiple forms in one Django view. from django.contrib import messages from django.views.generic import TemplateView from .forms import AddPostForm, AddCommentForm from .models import Comment class AddCommentView(TemplateView): post_form_class = AddPo...

python-social-auth is a framework that simplifies the social authentication and authorization mechanism. It contains many social backends (Facebook, Twitter, Github, LinkedIn, etc.) INSTALL First we need to install the python-social-auth package with pip install python-social-auth or download ...

Synopsis A fully functional demo of Firebase v3 Web authentication viewable here. Sign in with Facebook, Github, Google, Twitter, password based, and anonymous accounts. The code, available on Github, is easy to read and follow and is well documented. The focus is on the fully functional authent...

Here is a quick reference for advanced insertion, formatting, and filtering commands/shortcuts. Command/ShortcutResultg + ? + mPerform rot13 encoding, on movement mn + ctrl + a+n to number under cursorn + ctrl + x-n to number under cursorg + q+ mFormat lines of movement m to fixed width:rce wCenter...

When your app crashes, Xcode will enter the debugger and show you more information about the crash: The most important parts are: The red arrow The red arrow displays which line of code crashed & why it crashed. The debugger console Many crashes log more information to the debugger consol...

A SIGABRT or an EXC_BAD_INSTRUCTION usually means the app crashed itself intentionally because some check failed. These should log a message to the debugger console with more information; check there for more information. Many SIGABRTs are caused by uncaught Objective-C exceptions. There are a lo...

The following example shows how to set up Dependency Injection using Ninject as an IoC container. First add a CustomModule class to your WebJob project, and add any dependency bindings there. public class CustomModule : NinjectModule { public override void Load() { Bind<IMyI...

Mixins are similar to defining and calling functions. Say, if we need to create a repetitive style, mixins are handy. Mixins may or may not take parameters. For e.g.: .default-round-borders { border-radius: 5px; -moz-border-radius: 5px; -webkit-border-radius: 5px; } .round-b...

In Less, unlike Sass or Shell, the variables are declared by having names starting with a @ symbol. For example: @sky-blue: #87ceeb; body { background-color: @sky-blue; } The above example gives you: body { background-color: #87ceeb; } Here it explains how to declare a variable an...

Consider the following example: @sky-blue: #87ceeb; @dark-sky-blue: @sky-blue + #333; body { background-color: @dark-sky-blue; } The above example gives you: body { background-color: #baffff; } Here it explains how to declare a variable and also make operations on a particular va...

C++11 The std::is_same<T, T> type relation is used to compare two types. It will evaluate as boolean, true if the types are the same and false if otherwise. e.g. // Prints true on most x86 and x86_64 compilers. std::cout << std::is_same<int, int32_t>::value << "\n&qu...

Apart from types as a template parameter we are allowed to declare values of constant expressions meeting one of the following criteria: integral or enumeration type, pointer to object or pointer to function, lvalue reference to object or lvalue reference to function, pointer to member, st...

can either pass string of the json, or a filepath to a file with valid json In [99]: pd.read_json('[{"A": 1, "B": 2}, {"A": 3, "B": 4}]') Out[99]: A B 0 1 2 1 3 4 Alternatively to conserve memory: with open('test.json') as f: data = pd.Da...

def to_flare_json(df, filename): """Convert dataframe into nested JSON as in flare files used for D3.js""" flare = dict() d = {"name":"flare", "children": []} for index, row in df.iterrows(): parent = row[...

By default, npm installs the latest available version of modules according to each dependencies' semantic version. This can be problematic if a module author doesn't adhere to semver and introduces breaking changes in a module update, for example. To lock down each dependencies' version (and the ve...

Firstly you have to add Xamarin.Android.Support.V7.AppCompat library for NuGet: https://www.nuget.org/packages/Xamarin.Android.Support.v7.AppCompat/ In the "values" folder under "Resources" add new xml file called "styles.xml": "styles.xml" file should co...

Input record separator can be specified with -0 switch (zero, not capital O). It takes an octal or hexadecimal number as value. Any value 0400 or above will cause Perl to slurp files, but by convention, the value used for this purpose is 0777. perl -0777 -e 'my $file = <>; print length($file)...

%paste This is the primary Magic Method for pasting. It directly pastes text from the system clipboard, intelligently handling common issues with newlines and indentation. %cpaste If you are using IPython via SSH, use %cpaste instead, as it does not need to access the remote system clipbo...

Sometimes it's useful to check if a field is present or absent on your JSON to avoid some JSONException on your code. To achieve that, use the JSONObject#has(String) or the method, like on the following example: Sample JSON { "name":"James" } Java code String jsonStr...