trekhleb/learn-python ? reverse-engineered prompt

Build me a Python learning playground that teaches the basics through small topic based examples, like variables, operators, strings, lists, loops, functions, classes, modules, exceptions, files, and a few standard library modules.

I want each topic to have clear comments or a short explanation, plus simple assertions so I can run the examples and instantly see what should happen without needing a separate tutorial. Make it easy to edit the examples, add my own practice code, and check everything with tests and linting so I know I am writing it correctly.

Please organize it so it feels like a cheat sheet I can come back to later, with one place for each concept and enough examples to understand how Python works in real use. If anything needs current setup details, look up the latest docs online and keep the instructions simple.