Tutorial by Examples: d

git rm filename To delete the file from git without removing it from disk, use the --cached flag git rm --cached filename

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 ...

def multiply(s1, s2): print('{arg1} * {arg2} = {res}'.format(arg1=s1, arg2=s2, res=s1*s2)) return s1 * s2 asequence = [1, 2, 3] Given an initializer the function is started by applying it to the...

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

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] ...

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...

[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, ...

CREATE INDEX ix_cars_employee_id ON Cars (EmployeeId); This will create an index for the column EmployeeId in the table Cars. This index will improve the speed of queries asking the server to sort or select by values in EmployeeId, such as the following: SELECT * FROM Cars WHERE EmployeeId = 1 ...

Type the following code into your terminal, then press Enter: echo "Hello World" This will produce the following output: Hello World

Exponentiation can be used by using the builtin pow-function or the ** operator: 2 ** 3 # 8 pow(2, 3) # 8 For most (all in Python 2.x) arithmetic operations the result's type will be that of the wider operand. This is not true for **; the following cases are exceptions from this rule: B...

The math-module contains another math.pow() function. The difference to the builtin pow()-function or ** operator is that the result is always a float: import math math.pow(2, 2) # 4.0 math.pow(-2., 2) # 4.0 Which excludes computations with complex inputs: math.pow(2, 2+0j) TypeErro...

Both the math and cmath-module contain the Euler number: e and using it with the builtin pow()-function or **-operator works mostly like math.exp(): import math math.e ** 2 # 7.3890560989306495 math.exp(2) # 7.38905609893065 import cmath cmath.e ** 2 # 7.3890560989306495 cmath.exp(2) # (...

Supposing you have a class that stores purely integer values: class Integer(object): def __init__(self, value): self.value = int(value) # Cast to an integer def __repr__(self): return '{cls}({val})'.format(cls=self.__class__.__name__, ...

Click the Run button in the toolbar (or press ⌘R) to build & run your project. Click Stop (or press ⌘.) to stop execution.   Click & hold to see the other actions, Test (⌘U), Profile (⌘I), and Analyze (⇧⌘B). Hold down modifier keys ⌥ option, ⇧ shift, and ⌃ control for more variants.  ...

A submodule references a specific commit in another repository. To check out the exact state that is referenced for all submodules, run git submodule update --recursive Sometimes instead of using the state that is referenced you want to update to your local checkout to the latest state of that s...

You can have multiple versions of Xcode installed at the same time (including beta versions). Simply rename the application in Finder to avoid conflicts. Note: Installing Xcode from the App Store will tend to overwrite an existing version on your machine. You can also install Xcode from a direct ...