Python's Built-in Functions
The 25 built-ins worth memorizing, in tiers, and the 48 others you can look up as needed.
The long version: Built-in Functions in Python
Printable Python cheat sheets
Reference sheets, one printable page each. Each one distills what I've written on a topic into the version you can pin above your desk.
Free with a Python Morsels account. The article is the long version; the sheet is the part you keep looking up.
The button gives you US Letter, and every sheet comes in A4 too. The A4 version also prints at A3 unchanged, if you'd like a poster.
Python's String Methods
The dozen-ish string methods worth memorizing, the ones to skip, and what to reach for instead.
The long version: Python's String Methods
Python f-strings
Every part of a format specification, for numbers, strings, and dates, plus conversions and self-documenting expressions.
The long version: Python f-string tips & cheat sheets
Python Comprehensions
Turning a loop into a comprehension, mapping, filtering, nested loops, and the comprehensions you don't need.
Articles and screencasts: Comprehensions
Python Asterisks
Every prefix use of * and **: capturing arguments, unpacking into calls and literals, and merging dictionaries.
Articles and screencasts: Asterisks in Python
Python's pathlib Module
The anatomy of a Path, then reading, writing, finding, moving, and deleting files.
The long version: Python's pathlib module
Python Date Formats
Every % code for parsing and formatting dates and times, with the common formats spelled out.
The long version: Converting a string to a datetime
Python Regular Expressions
Characters, quantifiers, anchors, and groups, then searching, matching, replacing, and splitting with the re module.
Python Big O
What each list, dict, set, deque, and heap operation costs, and the curves those costs sit on.
The long version: Python Big O: the time complexities of different data structures in Python
The Python REPL
The keyboard shortcuts and modes of the Python 3.13+ REPL, with a diagram of how far each edit reaches.
The long version: Python REPL Shortcuts & Features
What's New in Python
How long each supported version gets fixes, upgrade tips, and the features worth knowing from each release.
Look up any feature: Since when? Which Python version added that
Python's Command-Line Tools
The standard library modules that double as command-line tools, from most useful to least, with the -m flag explained.
The long version: Python's many command-line utilities
More sheets are coming, one at a time.
If there's a Python topic you keep looking up and wish fit on one page, tell me at
[email protected].