Python Cheat Sheet

Python quick reference. Data types, functions, comprehensions, and common modules. Bookmark this page or print it.

Data Types

x = 1 / 3.14 / "str" / TrueBasic types

[1, 2, 3]List

(1, 2, 3)Tuple

{"a": 1, "b": 2}Dict

{1, 2, 3}Set

NoneNull value

[x*2 for x in range(10)]List comp

{k: v for k, v in items}Dict comp

{x for x in items if x > 0}Set comp

(x*2 for x in range(10))Generator

def f(a, b=1, *args, **kwargs):Function def

lambda x: x * 2Lambda

f"Hello {name}"F-string

@decoratorDecorator

yield valueGenerator

import os / os.pathOS operations

import json / json.dumps()JSON

import re / re.findall()Regex

import pathlib / Path()File paths

import datetime / datetime.now()Date/time

import collections / Counter()Collections

try: ... except: ...Try/except

try: ... except ValueError:Specific error

try: ... finally:Finally block

raise ValueError("msg")Raise error

open("file", "r")Open file

with open("f") as fp:Context manager

fp.read() / fp.readlines()Read file

fp.write("text")Write file