Python Cheatsheet

Core Python 3 syntax - data structures, comprehensions, and the built-in functions used constantly.

Data structures

[1, 2, 3]

List - ordered, mutable

(1, 2, 3)

Tuple - ordered, immutable

{1, 2, 3}

Set - unordered, unique values

{"key": "value"}

Dictionary - key-value pairs

[x*2 for x in range(5)]

List comprehension

{x: x*2 for x in range(5)}

Dict comprehension

[x for x in items if x > 0]

List comprehension with filter

f"{name} is {age}"

f-string interpolation

"{}-{}".format(a, b)

.format() method

str.strip()

Remove leading/trailing whitespace

str.split(",")

Split string into a list

",".join(list)

Join a list into a string

len(x)

Length of a list/string/dict

range(start, stop, step)

Generate a sequence of numbers

enumerate(list)

Loop with index and value

zip(list1, list2)

Pair up elements from two lists

sorted(list, key=fn)

Return a sorted copy

map(fn, list)

Apply a function to every item