gh-138859: Account for `ParamSpec` defaults that are not lists … (GH-138868)
(cherry picked from commit 379fd020a0)
Co-authored-by: bzoracler <50305397+bzoracler@users.noreply.github.com>
gh-139905: Provide suggestion in error message if `Generic.__init_subclass__` was not called (GH-139943)
(cherry picked from commit 5776d0d2e0)
Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
Union now uses the instance checks against its parameters instead of
the subclass checks.
(cherry picked from commit b2ac70a62a)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
gh-126699: allow AsyncIterator to be used as a base for Protocols (GH-126702)
(cherry picked from commit feb3e0b19c)
Co-authored-by: Stephen Morton <github@tungol.org>
- Only attempt to figure out whether protocol members are "method members" or not if the class is marked as a runtime protocol. This information is irrelevant for non-runtime protocols; we can safely skip the risky introspection for them.
- Only do the risky getattr() calls in one place (the runtime_checkable class decorator), rather than in three places (_ProtocolMeta.__init__, _ProtocolMeta.__instancecheck__ and _ProtocolMeta.__subclasscheck__). This reduces the number of locations in typing.py where the risky introspection could go wrong.
- For runtime protocols, if determining whether a protocol member is callable or not fails, give a better error message. I think it's reasonable for us to reject runtime protocols that have members which raise strange exceptions when you try to access them. PEP-544 clearly states that all protocol member must be callable for issubclass() calls against the protocol to be valid -- and if a member raises when we try to access it, there's no way for us to figure out whether it's a callable member or not!
Deprecate two methods of creating typing.TypedDict classes with 0 fields using the functional syntax: `TD = TypedDict("TD")` and `TD = TypedDict("TD", None)`. Both will be disallowed in Python 3.15. To create a TypedDict class with 0 fields, either use `class TD(TypedDict): pass` or `TD = TypedDict("TD", {})`.
Deprecate creating a typing.NamedTuple class using keyword arguments to denote the fields (`NT = NamedTuple("NT", x=int, y=str)`). This will be disallowed in Python 3.15. Use the class-based syntax or the functional syntax instead.
Two methods of creating `NamedTuple` classes with 0 fields using the functional syntax are also deprecated, and will be disallowed in Python 3.15: `NT = NamedTuple("NT")` and `NT = NamedTuple("NT", None)`. To create a `NamedTuple` class with 0 fields, either use `class NT(NamedTuple): pass` or `NT = NamedTuple("NT", [])`.
Mostly, these are changes so that we use shorter sentences and shorter paragraphs. In particular, I've tried to make the first sentence introducing each object in the typing API short and declarative.
