Type hinting Python functions. ... The user_id variable (which we could use to compare against the dictionary’s keys) can be an int or None (“no valid user”), but not a str.

Learn how Mypy's type checking works with functions and generators. In my last two articles I've described some of the ways Mypy, a type checker for Python, can help identify potential problems with ...

Mypy, Pytype, Pyright, and Pyre can help you keep your type-hinted Python code bug-free. Let’s see what each of these useful tools has to offer.