Python has a trait-like system. It's called "abstract base classes": https://docs.python.org/3/library/abc.html

The abstract base class should use the @abstractmethod decorator for methods that the implementing class needs to implement itself.

Obviously, you can also use abstract base classes in other ways, but they can be used as a way to define traits/interfaces for classes.

I'd really need to think long and hard about it, but my initial feeling is that we'd attach them to data classes or a similar new construct. I don't think you'd want to reason about the blast radius with ordinary classes. Granted, that's more language complexity, creates two unequal systems, and makes much more to reason about. There's a lot to juggle.

As much fun as putting a PEP together might be, I don't think I have the bandwidth to do so. I would really like to see traits in Python, though.

there were "traits" in python :/ . Search for pyprotocols.

(searching myself.. not much left of it)

2004 - https://simonwillison.net/2004/Mar/23/pyprotocols/

some related rejected PEP .. https://peps.python.org/pep-0246/ talking about something new to be expected.. in 2001?2005?

no idea did it happen and which one would that be..