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gh-103629: Update typing.Unpack docs in compliance with PEP 692 (#103894)
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@ -98,6 +98,9 @@ annotations. These include:
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*Introducing* :data:`LiteralString`
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* :pep:`681`: Data Class Transforms
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*Introducing* the :func:`@dataclass_transform<dataclass_transform>` decorator
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* :pep:`692`: Using ``TypedDict`` for more precise ``**kwargs`` typing
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*Introducing* a new way of typing ``**kwargs`` with :data:`Unpack` and
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:data:`TypedDict`
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* :pep:`698`: Adding an override decorator to typing
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*Introducing* the :func:`@override<override>` decorator
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@ -1417,8 +1420,10 @@ These are not used in annotations. They are building blocks for creating generic
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tup: tuple[Unpack[Ts]]
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In fact, ``Unpack`` can be used interchangeably with ``*`` in the context
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of types. You might see ``Unpack`` being used explicitly in older versions
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of Python, where ``*`` couldn't be used in certain places::
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of :class:`typing.TypeVarTuple <TypeVarTuple>` and
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:class:`builtins.tuple <tuple>` types. You might see ``Unpack`` being used
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explicitly in older versions of Python, where ``*`` couldn't be used in
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certain places::
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# In older versions of Python, TypeVarTuple and Unpack
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# are located in the `typing_extensions` backports package.
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@ -1428,6 +1433,21 @@ These are not used in annotations. They are building blocks for creating generic
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tup: tuple[*Ts] # Syntax error on Python <= 3.10!
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tup: tuple[Unpack[Ts]] # Semantically equivalent, and backwards-compatible
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``Unpack`` can also be used along with :class:`typing.TypedDict` for typing
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``**kwargs`` in a function signature::
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from typing import TypedDict, Unpack
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class Movie(TypedDict):
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name: str
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year: int
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# This function expects two keyword arguments - `name` of type `str`
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# and `year` of type `int`.
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def foo(**kwargs: Unpack[Movie]): ...
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See :pep:`692` for more details on using ``Unpack`` for ``**kwargs`` typing.
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.. versionadded:: 3.11
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.. class:: ParamSpec(name, *, bound=None, covariant=False, contravariant=False)
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@ -66,6 +66,10 @@ Summary -- Release highlights
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.. PEP-sized items next.
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New typing features:
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* :ref:`whatsnew312-pep692`
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Important deprecations, removals or restrictions:
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* :pep:`623`, Remove wstr from Unicode
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@ -145,6 +149,36 @@ New Features
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In Python 3.14, the default will switch to ``'data'``.
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(Contributed by Petr Viktorin in :pep:`706`.)
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New Features Related to Type Hints
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==================================
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This section covers major changes affecting :pep:`484` type hints and
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the :mod:`typing` module.
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.. _whatsnew312-pep692:
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PEP 692: Using ``TypedDict`` for more precise ``**kwargs`` typing
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-----------------------------------------------------------------
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Typing ``**kwargs`` in a function signature as introduced by :pep:`484` allowed
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for valid annotations only in cases where all of the ``**kwargs`` were of the
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same type.
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This PEP specifies a more precise way of typing ``**kwargs`` by relying on
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typed dictionaries::
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from typing import TypedDict, Unpack
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class Movie(TypedDict):
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name: str
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year: int
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def foo(**kwargs: Unpack[Movie]): ...
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See :pep:`692` for more details.
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(PEP written by Franek Magiera)
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Other Language Changes
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======================
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@ -0,0 +1,2 @@
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Mention the new way of typing ``**kwargs`` with ``Unpack`` and ``TypedDict``
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introduced in :pep:`692`.
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