I would love to instead have one official upstream runtime type checker which can be enabled per function, class, or module via decorators. Basically, providing

I would love to instead have one official upstream runtime type checker which can be enabled per function, class, or module via decorators. Basically, providing opt-in strong typing as a language feature. Currently, I’m using the third-party Beartype decorators to provide this feature, but I would prefer something built-in and ideally something with more readable error messages for users when type errors occur, which might be easier to provide if it was built into Python. (I use Pyright too, but I find the runtime type checking to be more robust since it understands also the types returned by highly dynamic untyped code.)