From 446be166861b2f08f87f74018113dd98ca5fca02 Mon Sep 17 00:00:00 2001 From: Serhiy Storchaka Date: Sun, 5 Dec 2021 22:42:50 +0200 Subject: bpo-45663: Fix is_dataclass() for dataclasses which are subclasses of types.GenericAlias (GH-29294) --- Lib/dataclasses.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Lib/dataclasses.py') diff --git a/Lib/dataclasses.py b/Lib/dataclasses.py index da06aa6914..3f85d859b1 100644 --- a/Lib/dataclasses.py +++ b/Lib/dataclasses.py @@ -1211,7 +1211,7 @@ def _is_dataclass_instance(obj): def is_dataclass(obj): """Returns True if obj is a dataclass or an instance of a dataclass.""" - cls = obj if isinstance(obj, type) else type(obj) + cls = obj if isinstance(obj, type) and not isinstance(obj, GenericAlias) else type(obj) return hasattr(cls, _FIELDS) -- cgit v1.2.1