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Interactive Shell The Bash shell is commonly used interactively: It lets you enter and edit commands, then executes them when you press the Return key. Many Unix-based and Unix-like operating systems use Bash as their default shell (notably Linux and macOS). The terminal automatically enters an int...

Extensions can contain functions and computed/constant get variables. They are in the format extension ExtensionOf { //new functions and get-variables } To reference the instance of the extended object, self can be used, just as it could be used To create an extension of String that adds ...

Extensions can contain convenience initializers. For example, a failable initializer for Int that accepts a NSString: extension Int { init?(_ string: NSString) { self.init(string as String) // delegate to the existing Int.init(String) initializer } } let str1: NSString = &qu...

This example show how to subscribe, and once that is successful, publishing a message to that channel. It also demonstrates the full set of parameters that can be included in the subscribe's message callback function. pubnub = PUBNUB({ publish_key : 'your_pub_key', ...

# No import needed # No import required... from functools import reduce # ... but it can be loaded from the functools module from functools import reduce # mandatory reduce reduces an iterable by applying a function repeatedly on the next element of an iterable and the cumulative resul...

import operator reduce(operator.mul, [10, 5, -3]) # Out: -150

reduce will not terminate the iteration before the iterable has been completly iterated over so it can be used to create a non short-circuit any() or all() function: import operator # non short-circuit "all" reduce(operator.and_, [False, True, True, True]) # = False # non short-circu...

# First falsy element or last element if all are truthy: reduce(lambda i, j: i and j, [100, [], 20, 10]) # = [] reduce(lambda i, j: i and j, [100, 50, 20, 10]) # = 10 # First truthy element or last element if all falsy: reduce(lambda i, j: i or j, [100, [], 20, 0]) # = 100 reduce(la...

Publish and Subscribe for Node.JS Install PubNub NPM Package. npm install [email protected] Example Publish Subscribe with Node.JS var channel = "hello_world"; var pubnub = require("pubnub")({ publish_key : "your_pub_key" , subscribe_key : "your_sub_ke...

When it comes to adding/removing channels to/from your channel groups, you need to have must have the manage permission for those channel groups. But you should never grant clients the permission to manage the channel groups that they will subscribe to. If they did, then they could add any channel t...

In addition to .done, .fail and .always promise callbacks, which are triggered based on whether the request was successful or not, there is the option to trigger a function when a specific HTTP Status Code is returned from the server. This can be done using the statusCode parameter. $.ajax({ t...

For example calculating the average of each i-th element of multiple iterables: def average(*args): return float(sum(args)) / len(args) # cast to float - only mandatory for python 2.x measurement1 = [100, 111, 99, 97] measurement2 = [102, 117, 91, 102] measurement3 = [104, 102, 95, 101] ...

Xcode projects are used to organize source files, library dependencies, and other resources, as well as the settings and steps required to build the project's products. Workspaces are groups of projects and other files. Create a project You can create a New Project (⇧⌘N) from a number of built-in ...

If the function parameter is None, then the identity function will be used: list(filter(None, [1, 0, 2, [], '', 'a'])) # discards 0, [] and '' # Out: [1, 2, 'a'] Python 2.x2.0.1 [i for i in [1, 0, 2, [], '', 'a'] if i] # equivalent list comprehension Python 3.x3.0.0 (i for i in [1, 0...

filter (python 3.x) and ifilter (python 2.x) return a generator so they can be very handy when creating a short-circuit test like or or and: Python 2.x2.0.1 # not recommended in real use but keeps the example short: from itertools import ifilter as filter Python 2.x2.6.1 from future_built...

There is a complementary function for filter in the itertools-module: Python 2.x2.0.1 # not recommended in real use but keeps the example valid for python 2.x and python 3.x from itertools import ifilterfalse as filterfalse Python 3.x3.0.0 from itertools import filterfalse which works...

First, install Node.js for your platform. In this example we'll create an HTTP server listening on port 1337, which sends Hello, World! to the browser. Note that, instead of using port 1337, you can use any port number of your choice which is currently not in use by any other service. The http mod...

Extensions are used to extend the functionality of existing types in Swift. Extensions can add subscripts, functions, initializers, and computed properties. They can also make types conform to protocols. Suppose you want to be able to compute the factorial of an Int. You can add a computed property...

[0-9] and \d are equivalent patterns (unless your Regex engine is unicode-aware and \d also matches things like ②). They will both match a single digit character so you can use whichever notation you find more readable. Create a string of the pattern you wish to match. If using the \d notation, you...

With the syntax: element { font: [font-style] [font-variant] [font-weight] [font-size/line-height] [font-family]; } You can have all your font-related styles in one declaration with the font shorthand. Simply use the font property, and put your values in the correct order. For example, ...