Make KT and VT private

Author: AA-Turner

typing_extensions/CHANGELOG

@@ -10,9 +10,11 @@ unneeded for supporting Python 3.7 and newer.
 
 - PEP_560
 - GenericMeta
+- KT
 - T
 - T_co
 - T_contra
+- VT
 
 # Release 4.0.1 (November 30, 2021)
 

typing_extensions/src/typing_extensions.py

@@ -78,11 +78,6 @@
 Deque = typing.Deque
 DefaultDict = typing.DefaultDict
 
-# Some unconstrained type variables.  These are used by the container types.
-# (These are not for export.)
-KT = typing.TypeVar('KT')  # Key type.
-VT = typing.TypeVar('VT')  # Value type.
-
 
 class _ReprForm(typing._SpecialForm, _root=True):
     def __repr__(self):
@@ -176,7 +171,11 @@ def __getitem__(self, parameters):
     OrderedDict = typing.OrderedDict
 # 3.7.0-3.7.2
 else:
-    OrderedDict = typing._alias(collections.OrderedDict, (KT, VT))
+    # Some unconstrained type variables.
+    # (These are not for export.)
+    _KT = typing.TypeVar('_KT')  # Key type.
+    _VT = typing.TypeVar('_VT')  # Value type.
+    OrderedDict = typing._alias(collections.OrderedDict, (_KT, _VT))
 
 _PROTO_WHITELIST = ['Callable', 'Awaitable',
                     'Iterable', 'Iterator', 'AsyncIterable', 'AsyncIterator',