Short, example-driven guides to one Python idea at a time.
Reading, writing, and organizing files
A short, example-driven guide to working with files in Python: opening them safely, handling text and encodings, using pathlib for paths, and reading and writing CSV and JSON. Nothing here needs a package you have to install, and every example was run when the book was built. By the end you can get data in and out of a file without looking it up.
Classes, dunder methods, and dataclasses
A focused, example-driven guide to classes in Python: __init__ and self, the dunder methods that make a class behave like a built-in type, class methods, inheritance versus composition, properties, and dataclasses. Standard library only, and every example was run when the book was built. By the end you can read a class-based codebase and design your own small class hierarchy without guessing.