The PEP-695 implementation added a new attribute __type_params__ to functions. I made this field read-only, but I realized there is a use case for writing to it: functools.wraps, when wrapping a generic function, should add the .__type_params__ to the wrapper. Making it writable is also more consistent with other fields on functions, as even the __name__ of functions is writable.

The PEP also adds a __type_params__ attribute to classes and type aliases. For classes it's already writable (it's just stored in the type's __dict__). For type aliases it's readonly, but as I don't see a use case for mutating a type alias's __type_params__, I'd like to keep it that way.

Linked PRs

• gh-104600: Make function.__type_params__ writable #104601
• gh-104600: Make type.__type_params__ writable #104634