`typing.rst` contains failing doctests

[sobolevn]

Bug report

» ./python.exe -m doctest Doc/library/typing.rst
**********************************************************************
File "Doc/library/typing.rst", line 1959, in typing.rst
Failed example:
    get_origin(P.args) is P
Exception raised:
    Traceback (most recent call last):
      File "/Users/sobolev/Desktop/cpython2/Lib/doctest.py", line 1374, in __run
        exec(compile(example.source, filename, "single",
      File "<doctest typing.rst[15]>", line 1, in <module>
        get_origin(P.args) is P
        ^^^^^^^^^^
    NameError: name 'get_origin' is not defined
**********************************************************************
File "Doc/library/typing.rst", line 1961, in typing.rst
Failed example:
    get_origin(P.kwargs) is P
Exception raised:
    Traceback (most recent call last):
      File "/Users/sobolev/Desktop/cpython2/Lib/doctest.py", line 1374, in __run
        exec(compile(example.source, filename, "single",
      File "<doctest typing.rst[16]>", line 1, in <module>
        get_origin(P.kwargs) is P
        ^^^^^^^^^^
    NameError: name 'get_origin' is not defined
**********************************************************************
1 items had failures:
   2 of  47 in typing.rst
***Test Failed*** 2 failures.
                               

My proposal is too:

1. Fix it
2. Add a test to test_typing to ensure that doctests pass

Linked PRs

• gh-111681: Fix doctests in typing.rst and remove unused imports #111682
• [3.12] gh-111681: minor fixes to typing doctests; remove unused imports in test_typing (#111682) #112035
• [3.11] gh-111681: minor fix to a typing doctest (#111682) #112037

[AlexWaygood]

The doctests in typing.rst aren't designed to be run via python -m doctest. They're designed to be run via Sphinx; we have special directives like this, which instruct Sphinx to run blocks of code prior to every doctest, but which wouldn't have any impact if you just ran the doctests via python -m doctest:

cpython/Doc/library/typing.rst

Lines 5 to 9 in d49aba5

	.. testsetup:: *
	import typing
	from dataclasses import dataclass
	from typing import *