Suffix T to type variable names (#4898)

* _MessageType to _MessageT

* _default to _T

* _TConnection to _ConnectionT, _TListener to _ListenerT

* _Number to _NumberT

* _MessageVar to _MessageT

* _Type to _TypeT

* _ArgType to _T

* _Ch to _CharT

Co-authored-by: hauntsaninja <>

stdlib/2/copy_reg.pyi

@@ -1,16 +1,16 @@
 from typing import Any, Callable, Hashable, List, Optional, SupportsInt, Tuple, TypeVar, Union
 
-_Type = TypeVar("_Type", bound=type)
-_Reduce = Union[Tuple[Callable[..., _Type], Tuple[Any, ...]], Tuple[Callable[..., _Type], Tuple[Any, ...], Optional[Any]]]
+_TypeT = TypeVar("_TypeT", bound=type)
+_Reduce = Union[Tuple[Callable[..., _TypeT], Tuple[Any, ...]], Tuple[Callable[..., _TypeT], Tuple[Any, ...], Optional[Any]]]
 
 __all__: List[str]
 
 def pickle(
-    ob_type: _Type,
-    pickle_function: Callable[[_Type], Union[str, _Reduce[_Type]]],
-    constructor_ob: Optional[Callable[[_Reduce[_Type]], _Type]] = ...,
+    ob_type: _TypeT,
+    pickle_function: Callable[[_TypeT], Union[str, _Reduce[_TypeT]]],
+    constructor_ob: Optional[Callable[[_Reduce[_TypeT]], _TypeT]] = ...,
 ) -> None: ...
-def constructor(object: Callable[[_Reduce[_Type]], _Type]) -> None: ...
+def constructor(object: Callable[[_Reduce[_TypeT]], _TypeT]) -> None: ...
 def add_extension(module: Hashable, name: Hashable, code: SupportsInt) -> None: ...
 def remove_extension(module: Hashable, name: Hashable, code: int) -> None: ...
 def clear_extension_cache() -> None: ...

stdlib/2/mutex.pyi

@@ -1,6 +1,6 @@
 from typing import Any, Callable, Deque, TypeVar
 
-_ArgType = TypeVar("_ArgType")
+_T = TypeVar("_T")
 
 class mutex:
     locked: bool
@@ -8,5 +8,5 @@ class mutex:
     def __init__(self) -> None: ...
     def test(self) -> bool: ...
     def testandset(self) -> bool: ...
-    def lock(self, function: Callable[[_ArgType], Any], argument: _ArgType) -> None: ...
+    def lock(self, function: Callable[[_T], Any], argument: _T) -> None: ...
     def unlock(self) -> None: ...