I have been investigating this:
```Python
from numbers import Real
def positive(x: Real) -> bool:
return x > 0 # Type Check failed!
```

#PEP 484 said that one should use `float` instead, but this does not solve for other numerical types e.g. #GMP numbers or #NumPy numbers.

And I found some old threads like https://github.com/python/typing/issues/1663
https://github.com/python/mypy/issues/3186
https://discuss.python.org/t/numeric-generics-where-do-we-go-from-pep-3141-and-present-day-mypy/17155
https://discuss.python.org/t/clarifying-the-float-int-complex-special-case/54018/26

And it seems like none has make any real progress.

To my understanding, ABC should also provides a good protocol for typing, just like typeclasses in #Haskell.

#Python #Typing #MyPy #Pyright

@seungjin ... #pyright bas the problems of JS : slow....

Python devs are waiting for #ty a rust type checker, built by astral, the ones who did #ruff and #UV

@seungjin I write #python code every day, and type hints are a "syntactic sugar" and are not required at all from the interpreter point of view.

For large projects, it's useful to add hints to "follow" what you are doing, and type checkers like #pyright or #mypy can help to find some bugs, by example when calling a method with wrong parameters types.

It also help for the readability of the code.