Remove unnecessary union in the default type in .get() and .pop() methods

Fixes python#10293.

Author: superbobry

stdlib/builtins.pyi

@@ -1082,11 +1082,11 @@ class dict(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
     @overload
     def get(self, __key: _KT) -> _VT | None: ...
     @overload
-    def get(self, __key: _KT, __default: _VT | _T) -> _VT | _T: ...
+    def get(self, __key: _KT, __default: _T) -> _VT | _T: ...
     @overload
     def pop(self, __key: _KT) -> _VT: ...
     @overload
-    def pop(self, __key: _KT, __default: _VT | _T) -> _VT | _T: ...
+    def pop(self, __key: _KT, __default: _T) -> _VT | _T: ...
     def __len__(self) -> int: ...
     def __getitem__(self, __key: _KT) -> _VT: ...
     def __setitem__(self, __key: _KT, __value: _VT) -> None: ...

stdlib/collections/__init__.pyi

@@ -414,7 +414,7 @@ class ChainMap(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
     @overload
     def pop(self, key: _KT) -> _VT: ...
     @overload
-    def pop(self, key: _KT, default: _VT | _T) -> _VT | _T: ...
+    def pop(self, key: _KT, default: _T) -> _VT | _T: ...
     def copy(self) -> Self: ...
     __copy__ = copy
     # All arguments to `fromkeys` are passed to `dict.fromkeys` at runtime, so the signature should be kept in line with `dict.fromkeys`.

stdlib/contextvars.pyi

@@ -24,10 +24,10 @@ class ContextVar(Generic[_T]):
     def get(self) -> _T: ...
     if sys.version_info >= (3, 8):
         @overload
-        def get(self, default: _D | _T) -> _D | _T: ...
+        def get(self, default: _D) -> _D | _T: ...
     else:
         @overload
-        def get(self, __default: _D | _T) -> _D | _T: ...
+        def get(self, __default: _D) -> _D | _T: ...
 
     def set(self, __value: _T) -> Token[_T]: ...
     def reset(self, __token: Token[_T]) -> None: ...

stdlib/multiprocessing/managers.pyi

@@ -76,11 +76,11 @@ class DictProxy(BaseProxy, MutableMapping[_KT, _VT]):
     @overload
     def get(self, __key: _KT) -> _VT | None: ...
     @overload
-    def get(self, __key: _KT, __default: _VT | _T) -> _VT | _T: ...
+    def get(self, __key: _KT, __default: _T) -> _VT | _T: ...
     @overload
     def pop(self, __key: _KT) -> _VT: ...
     @overload
-    def pop(self, __key: _KT, __default: _VT | _T) -> _VT | _T: ...
+    def pop(self, __key: _KT, __default: _T) -> _VT | _T: ...
     def keys(self) -> list[_KT]: ...  # type: ignore[override]
     def items(self) -> list[tuple[_KT, _VT]]: ...  # type: ignore[override]
     def values(self) -> list[_VT]: ...  # type: ignore[override]

stdlib/typing.pyi

@@ -624,9 +624,9 @@ class Mapping(Collection[_KT], Generic[_KT, _VT_co]):
     def __getitem__(self, __key: _KT) -> _VT_co: ...
     # Mixin methods
     @overload
-    def get(self, __key: _KT) -> _VT_co | None: ...
+    def get(self, key: _KT) -> _VT_co | None: ...
     @overload
-    def get(self, __key: _KT, default: _VT_co | _T) -> _VT_co | _T: ...
+    def get(self, key: _KT, default: _T) -> _VT_co | _T: ...
     def items(self) -> ItemsView[_KT, _VT_co]: ...
     def keys(self) -> KeysView[_KT]: ...
     def values(self) -> ValuesView[_VT_co]: ...
@@ -641,7 +641,7 @@ class MutableMapping(Mapping[_KT, _VT], Generic[_KT, _VT]):
     @overload
     def pop(self, __key: _KT) -> _VT: ...
     @overload
-    def pop(self, __key: _KT, default: _VT | _T) -> _VT | _T: ...
+    def pop(self, __key: _KT, default: _T) -> _VT | _T: ...
     def popitem(self) -> tuple[_KT, _VT]: ...
     # This overload should be allowed only if the value type is compatible with None.
     #

stdlib/weakref.pyi

@@ -74,7 +74,7 @@ class WeakValueDictionary(MutableMapping[_KT, _VT]):
     @overload
     def pop(self, key: _KT) -> _VT: ...
     @overload
-    def pop(self, key: _KT, default: _VT | _T = ...) -> _VT | _T: ...
+    def pop(self, key: _KT, default: _T = ...) -> _VT | _T: ...
     if sys.version_info >= (3, 9):
         def __or__(self, other: Mapping[_T1, _T2]) -> WeakValueDictionary[_KT | _T1, _VT | _T2]: ...
         def __ror__(self, other: Mapping[_T1, _T2]) -> WeakValueDictionary[_KT | _T1, _VT | _T2]: ...
@@ -117,7 +117,7 @@ class WeakKeyDictionary(MutableMapping[_KT, _VT]):
     @overload
     def pop(self, key: _KT) -> _VT: ...
     @overload
-    def pop(self, key: _KT, default: _VT | _T = ...) -> _VT | _T: ...
+    def pop(self, key: _KT, default: _T = ...) -> _VT | _T: ...
     if sys.version_info >= (3, 9):
         def __or__(self, other: Mapping[_T1, _T2]) -> WeakKeyDictionary[_KT | _T1, _VT | _T2]: ...
         def __ror__(self, other: Mapping[_T1, _T2]) -> WeakKeyDictionary[_KT | _T1, _VT | _T2]: ...

tests/stubtest_allowlists/py37.txt

@@ -28,7 +28,6 @@ collections.ByteString  # see comments in py3_common.txt
 collections.Callable
 collections.Mapping.__reversed__  # Set to None at runtime for a better error message
 configparser.ParsingError.filename
-contextvars.ContextVar.get
 dummy_threading.Condition.acquire
 dummy_threading.Condition.release
 dummy_threading.Event.isSet
@@ -68,7 +67,6 @@ collections.Generator.gi_code
 collections.Generator.gi_frame
 collections.Generator.gi_running
 collections.Generator.gi_yieldfrom
-collections.Mapping.get  # Adding None to the Union messed up mypy
 collections.Sequence.index  # Supporting None in end is not mandatory
 
 # SpooledTemporaryFile implements IO except these methods before Python 3.11

tests/stubtest_allowlists/py38.txt

@@ -87,7 +87,6 @@ collections.Generator.gi_code
 collections.Generator.gi_frame
 collections.Generator.gi_running
 collections.Generator.gi_yieldfrom
-collections.Mapping.get  # Adding None to the Union messed up mypy
 collections.Sequence.index  # Supporting None in end is not mandatory
 
 # SpooledTemporaryFile implements IO except these methods before Python 3.11

tests/stubtest_allowlists/py39.txt

@@ -91,7 +91,6 @@ collections.Generator.gi_code
 collections.Generator.gi_frame
 collections.Generator.gi_running
 collections.Generator.gi_yieldfrom
-collections.Mapping.get  # Adding None to the Union messed up mypy
 collections.Sequence.index  # Supporting None in end is not mandatory
 
 # Exists at runtime, but missing from stubs

tests/stubtest_allowlists/py3_common.txt

@@ -7,10 +7,8 @@
 _csv.Dialect.__init__  # C __init__ signature is inaccurate
 _ctypes.CFuncPtr  # stubtest erroneously thinks it can't be subclassed
 _threading_local.local.__new__
-builtins.dict.get
 builtins.ellipsis  # type is not exposed anywhere
 builtins.function
-collections.ChainMap.get  # Adding None to the underlying Mapping Union messed up mypy
 collections.ChainMap.fromkeys  # Runtime has *args which can really only be one argument
 collections.UserList.sort  # Runtime has *args but will error if any are supplied
 configparser.SectionProxy.__getattr__  # SectionProxy can have arbitrary attributes when custom converters are used
@@ -103,9 +101,7 @@ typing.IO.__next__  # Added because IO streams are iterable. See https://github.
 typing.type_check_only  # typing decorator that is not available at runtime
 unittest.mock.patch  # It's a complicated overload and I haven't been able to figure out why stubtest doesn't like it
 urllib.request.HTTPPasswordMgrWithPriorAuth.__init__  # Args are passed as is to super, so super args are specified
-weakref.WeakKeyDictionary.get
 weakref.WeakKeyDictionary.update
-weakref.WeakValueDictionary.get
 xml.parsers.expat.expat_CAPI
 
 # ==========
@@ -248,7 +244,6 @@ _collections_abc.Generator.gi_frame
 _collections_abc.Generator.gi_running
 _collections_abc.Generator.gi_yieldfrom
 _collections_abc.Mapping.__reversed__  # set to None at runtime for a better error message
-_collections_abc.Mapping.get  # Adding None to the Union messed up mypy
 _collections_abc.Sequence.index  # Supporting None in end is not mandatory
 
 # Adding these reflected dunders to `typing.AbstractSet` causes a large number of false-positives. See #7414.