Tutorial by Examples: r

Assuming you set the upstream (as in the "setting an upstream repository") git fetch remote-name git merge remote-name/branch-name The pull command combines a fetch and a merge. git pull The pull with --rebase flag command combines a fetch and a rebase instead of merge. git pull ...

You can make Git ignore certain files and directories — that is, exclude them from being tracked by Git — by creating one or more .gitignore files in your repository. In software projects, .gitignore typically contains a listing of files and/or directories that are generated during the build proces...

Setting a specific Seed will create a fixed random-number series: random.seed(5) # Create a fixed state print(random.randrange(0, 10)) # Get a random integer between 0 and 9 # Out: 9 print(random.randrange(0, 10)) # Out: 4 Resetting the seed will create the same &qu...

import java.awt.Image; import javax.imageio.ImageIO; ... try { Image img = ImageIO.read(new File("~/Desktop/cat.png")); } catch (IOException e) { e.printStackTrace(); }

x > y x < y These operators compare two types of values, they're the less than and greater than operators. For numbers this simply compares the numerical values to see which is larger: 12 > 4 # True 12 < 4 # False 1 < 4 # True For strings they will compare lexicographical...

Use the import statement: >>> import random >>> print(random.randint(1, 10)) 4 import module will import a module and then allow you to reference its objects -- values, functions and classes, for example -- using the module.name syntax. In the above example, the random module...

Instead of importing the complete module you can import only specified names: from random import randint # Syntax "from MODULENAME import NAME1[, NAME2[, ...]]" print(randint(1, 10)) # Out: 5 from random is needed, because the python interpreter has to know from which resource it...

#include <stdio.h> /* increment: take number, increment it by one, and return it */ int increment(int i) { printf("increment %d by 1\n", i); return i + 1; } /* decrement: take number, decrement it by one, and return it */ int decrement(int i) { printf("...

#include <stdio.h> enum Op { ADD = '+', SUB = '-', }; /* add: add a and b, return result */ int add(int a, int b) { return a + b; } /* sub: subtract b from a, return result */ int sub(int a, int b) { return a - b; } /* getmath: return the appropriate m...

Using typedef It might be handy to use a typedef instead of declaring the function pointer each time by hand. The syntax for declaring a typedef for a function pointer is: typedef returnType (*name)(parameters); Example: Posit that we have a function, sort, that expects a function pointer to ...

A basic "Hello, World!" program in Haskell can be expressed concisely in just one or two lines: main :: IO () main = putStrLn "Hello, World!" The first line is an optional type annotation, indicating that main is a value of type IO (), representing an I/O action which "...

from module_name import * for example: from math import * sqrt(2) # instead of math.sqrt(2) ceil(2.7) # instead of math.ceil(2.7) This will import all names defined in the math module into the global namespace, other than names that begin with an underscore (which indicates that the wri...

You can compare multiple items with multiple comparison operators with chain comparison. For example x > y > z is just a short form of: x > y and y > z This will evaluate to True only if both comparisons are True. The general form is a OP b OP c OP d ... Where OP represents ...

min(7,2,1,5) # Output: 1 max(7,2,1,5) # Output: 7

Finding the minimum/maximum of a sequence of sequences is possible: list_of_tuples = [(0, 10), (1, 15), (2, 8)] min(list_of_tuples) # Output: (0, 10) but if you want to sort by a specific element in each sequence use the key-argument: min(list_of_tuples, key=lambda x: x[0]) # Sorting ...

You can't pass an empty sequence into max or min: min([]) ValueError: min() arg is an empty sequence However, with Python 3, you can pass in the keyword argument default with a value that will be returned if the sequence is empty, instead of raising an exception: max([], default=42) ...

Create a file hello.html with the following content: <!DOCTYPE html> <html> <head> <title>Hello, World!</title> </head> <body> <div> <p id="hello">Some random text</p> </div> <script src=...

Arrays can be created by enclosing a list of elements in square brackets ([ and ]). Array elements in this notation are separated with commas: array = [1, 2, 3, 4] Arrays can contain any kind of objects in any combination with no restrictions on type: array = [1, 'b', nil, [3, 4]]

Arrays of strings can be created using ruby's percent string syntax: array = %w(one two three four) This is functionally equivalent to defining the array as: array = ['one', 'two', 'three', 'four'] Instead of %w() you may use other matching pairs of delimiters: %w{...}, %w[...] or %w<...&...

2.0 array = %i(one two three four) Creates the array [:one, :two, :three, :four]. Instead of %i(...), you may use %i{...} or %i[...] or %i!...! Additionally, if you want to use interpolation, you can do this with %I. 2.0 a = 'hello' b = 'goodbye' array_one = %I(#{a} #{b} world) array_tw...