PEP 655 (Required TypedDict items) tracker

[srittau]

This issue is supposed to track when we can start to use Required/NotRequired (PEP 655) in typeshed. Support is needed in released versions of:

• PEP accepted
• mypy (PEP 655: Support Required[] inside TypedDict mypy#10370)
• pytype
• pyright (Implement support for PEP 655 microsoft/pyright#1554)
• pyre
• PyCharm (PY-53611)

[JelleZijlstra]

I feel like we should also wait for the PEP to be accepted. typing-extensions can include experimental features that may be rejected, but typeshed should not.

[srittau]

This is now fully supported in mypy.

[JelleZijlstra]

I think it supports only one of Required and NotRequired? That's what the initial PR said but I haven't verified with the release.

[srittau]

Quick tests confirms that it works with both:

from typing_extensions import TypedDict, Required, NotRequired

class NonTotal(TypedDict, total=False):
    foo: int
    bar: Required[str]
    
nt1: NonTotal = {"foo": 123, "bar": ""}
nt2: NonTotal = {"foo": "", "bar": 123}  # incompatible types
nt3: NonTotal = {"foo": 123}  # missing key "bar"
nt4: NonTotal = {"bar": ""}

class Total(TypedDict, total=True):
    foo: int
    bar: NotRequired[str]
    
t1: Total = {"foo": 123, "bar": ""}
t2: Total = {"foo": "", "bar": 123}  # incompatible types
t3: Total = {"bar": ""}  # missing key "foo"
t4: Total = {"foo": 123}  

[gregoiredx]

Hello @srittau, just to let you know you can check the "PEP accepted" checkbox, see https://groups.google.com/g/dev-python/c/odKM_OpDES0 and https://peps.python.org/pep-0655/

[srittau]

Thanks, done!

[srittau]

I've used NotRequired in #8089 and our tests passed. So it seems that pytype at least accepts NotRequired, even if it doesn't fully support it, which would be enough for me. Cc @rchen152 for feedback.

Also cc @pradeep90 and @shannonzhu: Does pyre support Required/NotRequired for TypedDict?

[pradeep90]

I've used NotRequired in #8089 and our tests passed. So it seems that pytype at least accepts NotRequired, even if it doesn't fully support it, which would be enough for me. Cc @rchen152 for feedback.

Also cc @pradeep90 and @shannonzhu: Does pyre support Required/NotRequired for TypedDict?

@srittau No, we don't yet support Required/NotRequired. I'll implement it by the end of the month.

[lancelote]

Available in PyCharm >= 2022.2 EAP 4 https://youtrack.jetbrains.com/issue/PY-53611/Support-PEP-655-typingRequiredtypingNotRequired-for-TypedDicts

[pradeep90]

@srittau No, we don't yet support Required/NotRequired. I'll implement it by the end of the month.

Added support in Pyre v0.9.15.

[srittau]

Since the pytype checks run against the zxcvbn stubs, which already use NotRequired successfully and all other type checkers support it, I'm closing this. 🎉