From c3b9592244a9112d8af9610ff1c4e1e4cd4bfaca Mon Sep 17 00:00:00 2001 From: Dominik1123 <15989985+Dominik1123@users.noreply.github.com> Date: Mon, 16 Nov 2020 02:30:55 +0100 Subject: [PATCH] bpo-42317: Improve docs of typing.get_args concerning Union (GH-23254) --- Doc/library/typing.rst | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Doc/library/typing.rst b/Doc/library/typing.rst index 9a993c07327..a8de984a5ce 100644 --- a/Doc/library/typing.rst +++ b/Doc/library/typing.rst @@ -1706,6 +1706,9 @@ Introspection helpers For a typing object of the form ``X[Y, Z, ...]`` these functions return ``X`` and ``(Y, Z, ...)``. If ``X`` is a generic alias for a builtin or :mod:`collections` class, it gets normalized to the original class. + If ``X`` is a :class:`Union` contained in another generic type, + the order of ``(Y, Z, ...)`` may be different from the order of + the original arguments ``[Y, Z, ...]`` due to type caching. For unsupported objects return ``None`` and ``()`` correspondingly. Examples::