Python's optional type hints even with mypy are nowhere near strict/expressive than a statically typed language like Go. Type hints in Python are an afterthought and it shows in a lot of cases.
You can create sum types (a bit verbose but they are there).
You can introspect them at run time and create things like pydantic[0] and fastapi[1].
Strict null checks with Optional[T] are great!
Now I'm not too familiar with Go's type system, but with protocols, Unions, Optional[T] and other generics offered by MyPy[2] I'd wager the type system is __more__ expressive than Go.
[0]: https://pydantic-docs.helpmanual.io [1]: https://fastapi.tiangolo.com [2]: https://mypy.readthedocs.io/en/stable/protocols.html