Replace Mapping with types.MappingProxyType (#6013)

Mark `Signature.parameters` and `.return_annotation` as read-only properties

stdlib/dataclasses.pyi

@@ -1,4 +1,5 @@
 import sys
+import types
 from typing import Any, Callable, Generic, Iterable, Mapping, Tuple, Type, TypeVar, overload
 from typing_extensions import Protocol
 
@@ -77,7 +78,7 @@ class Field(Generic[_T]):
     hash: bool | None
     init: bool
     compare: bool
-    metadata: Mapping[Any, Any]
+    metadata: types.MappingProxyType[Any, Any]
     if sys.version_info >= (3, 10):
         kw_only: bool
         def __init__(

stdlib/email/headerregistry.pyi

@@ -1,4 +1,5 @@
 import sys
+import types
 from datetime import datetime as _datetime
 from email._header_value_parser import (
     AddressList,
@@ -11,7 +12,7 @@ from email._header_value_parser import (
 )
 from email.errors import MessageDefect
 from email.policy import Policy
-from typing import Any, Iterable, Mapping, Tuple, Type
+from typing import Any, Iterable, Tuple, Type
 
 class BaseHeader(str):
     @property
@@ -74,7 +75,7 @@ class MIMEVersionHeader:
 
 class ParameterizedMIMEHeader:
     @property
-    def params(self) -> Mapping[str, Any]: ...
+    def params(self) -> types.MappingProxyType[str, Any]: ...
     @classmethod
     def parse(cls, value: str, kwds: dict[str, Any]) -> None: ...
 

stdlib/enum.pyi

@@ -1,7 +1,8 @@
 import sys
+import types
 from abc import ABCMeta
 from builtins import property as _builtins_property
-from typing import Any, Iterator, Mapping, Type, TypeVar
+from typing import Any, Iterator, Type, TypeVar
 
 _T = TypeVar("_T")
 _S = TypeVar("_S", bound=Type[Enum])
@@ -17,7 +18,7 @@ class EnumMeta(ABCMeta):
     def __contains__(self: Type[Any], member: object) -> bool: ...
     def __getitem__(self: Type[_T], name: str) -> _T: ...
     @_builtins_property
-    def __members__(self: Type[_T]) -> Mapping[str, _T]: ...
+    def __members__(self: Type[_T]) -> types.MappingProxyType[str, _T]: ...
     def __len__(self) -> int: ...
     _member_names_: list[str]  # undocumented
     _member_map_: dict[str, Enum]  # undocumented

stdlib/functools.pyi

@@ -1,21 +1,7 @@
 import sys
+import types
 from _typeshed import SupportsItems, SupportsLessThan
-from typing import (
-    Any,
-    Callable,
-    Generic,
-    Hashable,
-    Iterable,
-    Mapping,
-    NamedTuple,
-    Sequence,
-    Set,
-    Sized,
-    Tuple,
-    Type,
-    TypeVar,
-    overload,
-)
+from typing import Any, Callable, Generic, Hashable, Iterable, NamedTuple, Sequence, Set, Sized, Tuple, Type, TypeVar, overload
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -86,7 +72,7 @@ class partialmethod(Generic[_T]):
         def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class _SingleDispatchCallable(Generic[_T]):
-    registry: Mapping[Any, Callable[..., _T]]
+    registry: types.MappingProxyType[Any, Callable[..., _T]]
     def dispatch(self, cls: Any) -> Callable[..., _T]: ...
     # @fun.register(complex)
     # def _(arg, verbose=False): ...

stdlib/inspect.pyi

@@ -1,5 +1,6 @@
 import enum
 import sys
+import types
 from _typeshed import Self
 from collections import OrderedDict
 from collections.abc import Awaitable, Callable, Generator, Mapping, Sequence, Set
@@ -120,11 +121,11 @@ class Signature:
     def __init__(self, parameters: Sequence[Parameter] | None = ..., *, return_annotation: Any = ...) -> None: ...
     # TODO: can we be more specific here?
     empty: object
-
-    parameters: Mapping[str, Parameter]
-
+    @property
+    def parameters(self) -> types.MappingProxyType[str, Parameter]: ...
     # TODO: can we be more specific here?
-    return_annotation: Any
+    @property
+    def return_annotation(self) -> Any: ...
     def bind(self, *args: Any, **kwargs: Any) -> BoundArguments: ...
     def bind_partial(self, *args: Any, **kwargs: Any) -> BoundArguments: ...
     def replace(self: Self, *, parameters: Sequence[Parameter] | None = ..., return_annotation: Any = ...) -> Self: ...