Accessing type arguments inside __init__

[mitar]

It seems this is not possible?

Example:

import typing

T = typing.TypeVar('T')

class Foo(typing.Generic[T]):
    def __init__(self):
        print(type(self).__args__)

A = Foo[int]
A()

I would expect that this prints out int as __args__, but it does not. It seems because runtime class is Foo, not Foo[int].

[ilevkivskyi]

It seems because runtime class is Foo, not Foo[int].

Yes, and this is intentional. The original class is stored in __orig_class__ this is however not an official API. Or you can better use typing_inspect.get_generic_type(obj) which is a thin wrapper around this API.

[mitar]

Oh, thank you for quick response.