trekhleb/learn-python

learn-python is a collection of Python scripts designed to teach you the Python programming language through hands-on examples and a built-in cheat sheet. Python is a popular, beginner-friendly programming language used for everything from web apps to data analysis. The repository is organized by topic, covering things like variables, data types, control flow (if/for/while statements), functions, classes, error handling, file reading, and parts of Python's standard library. Each script follows the same pattern: a brief explanation at the top, then code examples paired with assertions (checks that confirm what the output should be), so you can see exactly what each piece of code does without having to run it yourself. The "playground" aspect means you can open any script, tweak the code, add your own examples, and run the built-in tests to see if your changes work. This makes learning interactive rather than passive, you experiment directly in the code instead of just reading about it. The "cheatsheet" aspect means you can return later to quickly look up Python syntax you've forgotten, like how lists work or how to handle exceptions. The repository is written in Python 3 and covers beginner-to-intermediate ground. You would use it if you are new to Python and want structured, runnable examples to practice with, or if you already know some Python and need a quick reference for syntax. It also supports linting so you can check whether your code follows Python style conventions.