Coming back from TypeScript to Python, I found that most recent (3.10+) typing annotation shorthands are pretty succinct, and running mypy at all times really h

Coming back from TypeScript to Python, I found that most recent (3.10+) typing annotation shorthands are pretty succinct, and running mypy at all times really helps cut down on runtime errors. My recipe: — annotate variables, attributes, arguments and return values; — run a good type linter (we use mypy) at all times; — never pass around generic dictionaries: use dataclasses[0], TypedDicts, etc. instead. That way you define a subclass inheriting from, say, TypedDict and declare that your function only takes that subclass. After that, you’ll get a loud error if you pass any dictionary that doesn’t match the spec (missing keys, wrong values, etc.)—ideally, right in your IDE. (To reiterate, this would be a pointless exercise if you don’t lint all the time; most IDEs support this.) [0] You can additionally use them with Pydantic, which can validate data at runtime at a cost of some performance overhead.