@final(TypedDict).get() with unknown key returns object instead of None

Original report:

With:

from typing import TypedDict, final

@final
class A(TypedDict):
    """Empty"""

a: A = {}
reveal_type(a.get("foo", None))

I expect to get None, but instead get object | Any.

Maybe the object should be replaced with None here? https://github.com/python/typeshed/blob/master/stdlib/typing.pyi#L717-L728
I'm not too sure how that works.

Actually the issue is get("missing_key", foo) cannot infer correct type. #9906 (comment) Jukka explained this before.

Does object | Any not still seem wrong? Going with the spirit of the comment we shouldn't be inferring an Any at all, it seems object | None would make more sense no?

Does object | Any not still seem wrong?

I can only get object on master branch

Actually the issue is get("missing_key", foo) cannot infer correct type. #9906 (comment) Jukka explained this before.

I think the real issue why this can't be inferred is the allowance of inheritance. I think there was a conversation about this elsewhere, but my example can't work, as you could create a subclass with any other type like:

class A(TypedDict): ...

class B(A):
    foo: str

b: B = {"foo": "bar"}
a: A = b
reveal_type(a.get("foo", None))

In the future, it might be possible to support my example using final types:

@final
class A(TypedDict): ...

At that point, there is no reason it can't be inferred. The key is a literal and it can be checked what type it should return (or no type if not present).

Another example of the issue:

import typing


@typing.final
class Node(typing.TypedDict):
    name: str
    children: list[typing.Union['Node', 'Leaf']]


@typing.final
class Leaf(typing.TypedDict):
    name: str


x: Node | Leaf
reveal_type(x.get('children', []))

The inferred type should be list[Node], not builtins.object.

Just to confirm for more visibility: @final decorator on TypedDicts is now soft-deprecated (and is only supported on the best effort basis), for all relevant use cases, please use PEP 728 closed=True.

Implement support for closed TypedDicts (PEP 728) (python#21382)

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@final(TypedDict).get() with unknown key returns object instead of None #12143

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@final(TypedDict).get() with unknown key returns object instead of None #12143

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97littleleaf11 commented on Mar 19, 2022

jhance commented on Mar 19, 2022

97littleleaf11 commented on Mar 19, 2022

Dreamsorcerer commented on Mar 19, 2022

roganov commented on Apr 2, 2024

ilevkivskyi commented on Jun 2, 2026

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