mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-04 08:59:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 11

gh-118418: Deprecate failing to pass a value to the *type_params* parameter of some private typing APIs (#118695)

Browse source
This commit is contained in:
Alex Waygood 2024-05-07 12:12:28 +01:00 • committed by GitHub
parent 6f768b71ba
commit 0f8a07d158
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
3 changed files with 61 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

41
Lib/typing.py
View file

@ -437,13 +437,38 @@ def _tp_cache(func=None, /, *, typed=False):
return decorator
def _eval_type(t, globalns, localns, type_params=None, *, recursive_guard=frozenset()):
def _deprecation_warning_for_no_type_params_passed(funcname: str) -> None:
import warnings
depr_message = (
f"Failing to pass a value to the 'type_params' parameter "
f"of {funcname!r} is deprecated, as it leads to incorrect behaviour "
f"when calling {funcname} on a stringified annotation "
f"that references a PEP 695 type parameter. "
f"It will be disallowed in Python 3.15."
)
warnings.warn(depr_message, category=DeprecationWarning, stacklevel=3)
class _Sentinel:
__slots__ = ()
def __repr__(self):
return '<sentinel>'
_sentinel = _Sentinel()
def _eval_type(t, globalns, localns, type_params=_sentinel, *, recursive_guard=frozenset()):
"""Evaluate all forward references in the given type t.
For use of globalns and localns see the docstring for get_type_hints().
recursive_guard is used to prevent infinite recursion with a recursive
ForwardRef.
"""
if type_params is _sentinel:
_deprecation_warning_for_no_type_params_passed("typing._eval_type")
type_params = ()
if isinstance(t, ForwardRef):
return t._evaluate(globalns, localns, type_params, recursive_guard=recursive_guard)
if isinstance(t, (_GenericAlias, GenericAlias, types.UnionType)):
@ -1018,7 +1043,10 @@ class ForwardRef(_Final, _root=True):
self.__forward_is_class__ = is_class
self.__forward_module__ = module
def _evaluate(self, globalns, localns, type_params=None, *, recursive_guard):
def _evaluate(self, globalns, localns, type_params=_sentinel, *, recursive_guard):
if type_params is _sentinel:
_deprecation_warning_for_no_type_params_passed("typing.ForwardRef._evaluate")
type_params = ()
if self.__forward_arg__ in recursive_guard:
return self
if not self.__forward_evaluated__ or localns is not globalns:
@ -2998,15 +3026,6 @@ class NamedTupleMeta(type):
return nm_tpl
class _Sentinel:
__slots__ = ()
def __repr__(self):
return '<sentinel>'
_sentinel = _Sentinel()
def NamedTuple(typename, fields=_sentinel, /, **kwargs):
"""Typed version of namedtuple.