Every non-trivial Python program has a boundary where untrusted data enters: an API request body, a config file, an environment variable, a row from a CSV. The naive approach is to trust the shape of that data and let KeyError or TypeError surface deep inside your business logic when it doesn’t match. Pydantic moves that failure to the boundary, where it belongs, and gives you a typed, validated object instead of a bag of dicts and hope. ...
Every Python developer knows os, json, and collections. Far fewer reach for bisect when they need a sorted insert, or graphlib when they need a dependency order, and end up pulling in a third-party package (or writing worse code by hand) for something the standard library already does well. This is a tour of the modules that don’t get enough credit: what they do, and how they show up in real code. ...
Most Python programs still talk to their users through print(). That’s fine until you need a progress bar, a table, syntax-highlighted tracebacks, or just readable output that doesn’t run together into a wall of text. rich replaces print() with something that understands color, layout, and structure, and it does it without asking you to learn a templating language first. What it is Rich is a Python library for rendering formatted text, tables, progress bars, syntax-highlighted code, markdown, and tracebacks to the terminal. It detects what your terminal supports (truecolor, 256-color, or plain) and degrades gracefully, so the same code produces reasonable output whether it’s running in a modern terminal, a CI log, or a dumb pipe. ...