mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-04 17:08:35 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 13

gh-116127: PEP-705: Add ReadOnly support for TypedDict (#116350)

Browse source 
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
This commit is contained in:
Nikita Sobolev 2024-03-12 17:49:39 +03:00 • committed by GitHub
parent 3265087c07
commit df4784b3b7
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
5 changed files with 182 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

39
Doc/library/typing.rst
View file

@ -1274,6 +1274,26 @@ These can be used as types in annotations. They all support subscription using
.. versionadded:: 3.11
.. data:: ReadOnly
A special typing construct to mark an item of a :class:`TypedDict` as read-only.
For example::
class Movie(TypedDict):
title: ReadOnly[str]
year: int
def mutate_movie(m: Movie) -> None:
m["year"] = 1992 # allowed
m["title"] = "The Matrix" # typechecker error
There is no runtime checking for this property.
See :class:`TypedDict` and :pep:`705` for more details.
.. versionadded:: 3.13
.. data:: Annotated
Special typing form to add context-specific metadata to an annotation.
@ -2454,6 +2474,22 @@ types.
``__required_keys__`` and ``__optional_keys__`` rely on may not work
properly, and the values of the attributes may be incorrect.
Support for :data:`ReadOnly` is reflected in the following attributes::
.. attribute:: __readonly_keys__
A :class:`frozenset` containing the names of all read-only keys. Keys
are read-only if they carry the :data:`ReadOnly` qualifier.
.. versionadded:: 3.13
.. attribute:: __mutable_keys__
A :class:`frozenset` containing the names of all mutable keys. Keys
are mutable if they do not carry the :data:`ReadOnly` qualifier.
.. versionadded:: 3.13
See :pep:`589` for more examples and detailed rules of using ``TypedDict``.
.. versionadded:: 3.8
@ -2468,6 +2504,9 @@ types.
.. versionchanged:: 3.13
Removed support for the keyword-argument method of creating ``TypedDict``\ s.
.. versionchanged:: 3.13
Support for the :data:`ReadOnly` qualifier was added.
.. deprecated-removed:: 3.13 3.15
When using the functional syntax to create a TypedDict class, failing to
pass a value to the 'fields' parameter (``TD = TypedDict("TD")``) is