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/3/copyreg.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/3/multiprocessing/dummy/connection.pyi

@@ -4,8 +4,8 @@ from typing import Any, List, Optional, Tuple, Type, TypeVar, Union
 
 families: List[None]
 
-_TConnection = TypeVar("_TConnection", bound=Connection)
-_TListener = TypeVar("_TListener", bound=Listener)
+_ConnectionT = TypeVar("_ConnectionT", bound=Connection)
+_ListenerT = TypeVar("_ListenerT", bound=Listener)
 _Address = Union[str, Tuple[str, int]]
 
 class Connection(object):
@@ -15,7 +15,7 @@ class Connection(object):
     recv_bytes: Any
     send: Any
     send_bytes: Any
-    def __enter__(self: _TConnection) -> _TConnection: ...
+    def __enter__(self: _ConnectionT) -> _ConnectionT: ...
     def __exit__(
         self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
     ) -> None: ...
@@ -27,7 +27,7 @@ class Listener(object):
     _backlog_queue: Optional[Queue[Any]]
     @property
     def address(self) -> Optional[Queue[Any]]: ...
-    def __enter__(self: _TListener) -> _TListener: ...
+    def __enter__(self: _ListenerT) -> _ListenerT: ...
     def __exit__(
         self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
     ) -> None: ...

stdlib/3/statistics.pyi

@@ -6,7 +6,7 @@ from typing import Any, Hashable, Iterable, List, Optional, SupportsFloat, Type,
 
 _T = TypeVar("_T")
 # Most functions in this module accept homogeneous collections of one of these types
-_Number = TypeVar("_Number", float, Decimal, Fraction)
+_NumberT = TypeVar("_NumberT", float, Decimal, Fraction)
 
 # Used in mode, multimode
 _HashableT = TypeVar("_HashableT", bound=Hashable)
@@ -17,25 +17,25 @@ if sys.version_info >= (3, 8):
     def fmean(data: Iterable[SupportsFloat]) -> float: ...
     def geometric_mean(data: Iterable[SupportsFloat]) -> float: ...
 
-def mean(data: Iterable[_Number]) -> _Number: ...
-def harmonic_mean(data: Iterable[_Number]) -> _Number: ...
-def median(data: Iterable[_Number]) -> _Number: ...
+def mean(data: Iterable[_NumberT]) -> _NumberT: ...
+def harmonic_mean(data: Iterable[_NumberT]) -> _NumberT: ...
+def median(data: Iterable[_NumberT]) -> _NumberT: ...
 def median_low(data: Iterable[SupportsLessThanT]) -> SupportsLessThanT: ...
 def median_high(data: Iterable[SupportsLessThanT]) -> SupportsLessThanT: ...
-def median_grouped(data: Iterable[_Number], interval: _Number = ...) -> _Number: ...
+def median_grouped(data: Iterable[_NumberT], interval: _NumberT = ...) -> _NumberT: ...
 def mode(data: Iterable[_HashableT]) -> _HashableT: ...
 
 if sys.version_info >= (3, 8):
     def multimode(data: Iterable[_HashableT]) -> List[_HashableT]: ...
 
-def pstdev(data: Iterable[_Number], mu: Optional[_Number] = ...) -> _Number: ...
-def pvariance(data: Iterable[_Number], mu: Optional[_Number] = ...) -> _Number: ...
+def pstdev(data: Iterable[_NumberT], mu: Optional[_NumberT] = ...) -> _NumberT: ...
+def pvariance(data: Iterable[_NumberT], mu: Optional[_NumberT] = ...) -> _NumberT: ...
 
 if sys.version_info >= (3, 8):
-    def quantiles(data: Iterable[_Number], *, n: int = ..., method: str = ...) -> List[_Number]: ...
+    def quantiles(data: Iterable[_NumberT], *, n: int = ..., method: str = ...) -> List[_NumberT]: ...
 
-def stdev(data: Iterable[_Number], xbar: Optional[_Number] = ...) -> _Number: ...
-def variance(data: Iterable[_Number], xbar: Optional[_Number] = ...) -> _Number: ...
+def stdev(data: Iterable[_NumberT], xbar: Optional[_NumberT] = ...) -> _NumberT: ...
+def variance(data: Iterable[_NumberT], xbar: Optional[_NumberT] = ...) -> _NumberT: ...
 
 if sys.version_info >= (3, 8):
     class NormalDist: