Bug report

Bug description:

from typing import NotRequired, Required, TypedDict

class A(TypedDict):
    a: NotRequired[int]
    b: Required[int]

class B(A):
    a: Required[int]
    b: NotRequired[int]

print(B.__required_keys__)
print(B.__optional_keys__)

This will print (tried on 3.11 and current-ish main):

frozenset({'b', 'a'})
frozenset({'b', 'a'})

But obviously, a single key should only be either Required or NotRequired, not both. The child class's version should prevail.

@alicederyn and I discovered this while discussing the implementation of PEP-705 (python/typing_extensions#284). cc @davidfstr for PEP 655.

I also see some problems with how type checkers handle this case, but i'll post about that separately.

CPython versions tested on:

3.11, CPython main branch

Operating systems tested on:

macOS

Linked PRs

• gh-112509: Fix keys being present in both required_keys and optional_keys in TypedDict #112512
• [3.12] gh-112509: Fix keys being present in both required_keys and optional_keys in TypedDict (GH-112512) #112530
• [3.11] gh-112509: Fix keys being present in both required_keys and optional_keys in TypedDict (GH-112512) #112531