List Comprehensions
A concise way to create lists based on existing iterables.
Syntax
[expression for item in iterable if condition]Examples
# squares of 0-9
squares = [x**2 for x in range(10)]
# even numbers
evens = [x for x in range(20) if x % 2 == 0]
# uppercase words
words = ["hello", "world"]
upper = [w.upper() for w in words]
# flattening
matrix = [[1,2],[3,4],[5,6]]
flat = [n for row in matrix for n in row]Dict Comprehension
squares_dict = {x: x**2 for x in range(6)}