It's possible to create generator iterators using a comprehension-like syntax.
generator = (i * 2 for i in range(3))
next(generator) # 0
next(generator) # 2
next(generator) # 4
next(generator) # raises StopIteration
If a function doesn't necessarily need to be passed a list, you can sa...
An external CSS stylesheet can be applied to any number of HTML documents by placing a <link> element in each HTML document.
The attribute rel of the <link> tag has to be set to "stylesheet", and the href attribute to the relative or absolute path to the stylesheet. While usin...
Create a new HTML file and paste the following content:
<!DOCTYPE html>
<html ng-app>
<head>
<title>Hello, Angular</title>
<script src="https://code.angularjs.org/1.5.8/angular.min.js"></script>
</head>
<body ng-init="name=...
The background-color property sets the background color of an element using a color value or through keywords, such as transparent, inherit or initial.
transparent, specifies that the background color should be transparent. This is default.
inherit, inherits this property from its parent e...
Jsoup can be be used to easily extract all links from a webpage. In this case, we can use Jsoup to extract only specific links we want, here, ones in a h3 header on a page. We can also get the text of the links.
Document doc = Jsoup.connect("http://stackoverflow.com").userAgent("Mozi...
a, b = 1, 2
# Using the "+" operator:
a + b # = 3
# Using the "in-place" "+=" operator to add and assign:
a += b # a = 3 (equivalent to a = a + b)
import operator # contains 2 argument arithmetic functions for the examp...
CSS transforms are based on the size of the elements so if you don't know how tall or wide your element is, you can position it absolutely 50% from the top and left of a relative container and translate it by 50% left and upwards to center it vertically and horizontally.
Keep in mind that with this...
Create a new file called hello.sh with the following content and give it executable permissions with chmod +x hello.sh.
Execute/Run via: ./hello.sh
#!/usr/bin/env bash
# Note that spaces cannot be used around the `=` assignment operator
whom_variable="World"
# Use printf to sa...
a, b = 1, 2
# Using the "-" operator:
b - a # = 1
import operator # contains 2 argument arithmetic functions
operator.sub(b, a) # = 1
Possible combinations (builtin types):
int and int (gives an int)
int and float (gives a float)
int and comp...
Creating a database in MySQL
CREATE DATABASE mydb;
Return value:
Query OK, 1 row affected (0.05 sec)
Using the created database mydb
USE mydb;
Return value:
Database Changed
Creating a table in MySQL
CREATE TABLE mytable
(
id int unsigned NOT NULL auto_increme...
a, b = 2, 3
a * b # = 6
import operator
operator.mul(a, b) # = 6
Possible combinations (builtin types):
int and int (gives an int)
int and float (gives a float)
int and complex (gives a complex)
float and float (gives a float)
float and complex (gives a comple...
a, b = 2, 3
(a ** b) # = 8
pow(a, b) # = 8
import math
math.pow(a, b) # = 8.0 (always float; does not allow complex results)
import operator
operator.pow(a, b) # = 8
Another difference between the built-in pow and math.pow is that the built-in po...
By default, the math.log function calculates the logarithm of a number, base e. You can optionally specify a base as the second argument.
import math
import cmath
math.log(5) # = 1.6094379124341003
# optional base argument. Default is math.e
math.log(5, math.e) # = 1.6094379124341003
...
A practical use case of a generator is to iterate through values of an infinite series. Here's an example of finding the first ten terms of the Fibonacci Sequence.
def fib(a=0, b=1):
"""Generator that yields Fibonacci numbers. `a` and `b` are the seed values"""
...
Direction-Specific Properties
CSS allows you to specify a given side to apply margin to. The four properties provided for this purpose are:
margin-left
margin-right
margin-top
margin-bottom
The following code would apply a margin of 30 pixels to the left side of the selected div. View Resu...
You can include another Git repository as a folder within your project, tracked by Git:
$ git submodule add https://github.com/jquery/jquery.git
You should add and commit the new .gitmodules file; this tells Git what submodules should be cloned when git submodule update is run.
When you clone a repository that uses submodules, you'll need to initialize and update them.
$ git clone --recursive https://github.com/username/repo.git
This will clone the referenced submodules and place them in the appropriate folders (including submodules within submodules). This is equivale...
Anchors can be used to jump to specific tags on an HTML page. The <a> tag can point to any element that has an id attribute. To learn more about IDs, visit the documentation about Classes and IDs. Anchors are mostly used to jump to a subsection of a page and are used in conjunction with header...
Python provides string interpolation and formatting functionality through the str.format function, introduced in version 2.6 and f-strings introduced in version 3.6.
Given the following variables:
i = 10
f = 1.5
s = "foo"
l = ['a', 1, 2]
d = {'a': 1, 2: 'foo'}
The following statem...
