[3.12] typing: Improve documentation of generic classes and aliases (GH-105369) (#105453)

typing: Improve documentation of generic classes and aliases (GH-105369)
(cherry picked from commit d63a7c3694d5c4484fcaa01c33590b1d4bc2559e)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/Lib/typing.py b/Lib/typing.py
index 0983f20..0ff29fa 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -2549,11 +2549,13 @@ Callable = _CallableType(collections.abc.Callable, 2)
 Callable.__doc__ = \
     """Deprecated alias to collections.abc.Callable.
 
-    Callable[[int], str] signifies a function of (int) -> str.
+    Callable[[int], str] signifies a function that takes a single
+    parameter of type int and returns a str.
+
     The subscription syntax must always be used with exactly two
     values: the argument list and the return type.
-    The argument list must be a list of types, a ParamSpec or ellipsis.
-    The return type must be a single type.
+    The argument list must be a list of types, a ParamSpec,
+    Concatenate or ellipsis. The return type must be a single type.
 
     There is no syntax to indicate optional or keyword arguments;
     such function types are rarely used as callback types.