From e44c0ca52f3283a38676c5318d7fdc1045a98a8b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?tonghuaroot=20=28=E7=AB=A5=E8=AF=9D=29?=
 <tonghuaroot@gmail.com>
Date: Sat, 24 Oct 2026 14:59:54 +0800
Subject: [PATCH] gh-158856: Fix enum membership for values of a different
 hashability

Since _hashable_values_ became a set, `value in EnumClass` missed values
equal to a member value but of a different hashability, including a set
member's own value. Check the unhashable values on a miss and compare
against the hashable values on TypeError.
---
 Lib/enum.py           |  9 +++++++--
 Lib/test/test_enum.py | 17 +++++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/Lib/enum.py b/Lib/enum.py
index 8a6519e006515ab..6eb2d710b748f55 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -777,9 +777,14 @@ def __contains__(cls, value):
             except ValueError:
                 pass
         try:
-            return value in cls._hashable_values_                   # a set
+            if value in cls._hashable_values_:                      # a set
+                return True
         except TypeError:
-            return value in cls._unhashable_values_                 # a list
+            # an unhashable value can equal a hashable one, e.g. bytearray
+            for v in cls._hashable_values_:
+                if v == value:
+                    return True
+        return value in cls._unhashable_values_                     # a list
 
     def __delattr__(cls, attr):
         # nicer error message when someone tries to delete an attribute
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 447f847f33da938..68a4820af1f437b 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -3530,6 +3530,23 @@ class Directions(Enum):
             UNRESTRICTED = frozenset({"sc", "cs"})
         self.assertIs(Directions({"sc"}), Directions.DOWN_ONLY)
 
+    def test_contains_equal_value_of_other_hashability(self):
+        class Sets(Enum):
+            A = {1, 2}
+        class Magic(Enum):
+            PNG = b'\x89PNG'
+        class BytesMagic(bytes, Enum):
+            PNG = b'\x89PNG'
+        self.assertIn(Sets.A.value, Sets)
+        self.assertIn({1, 2}, Sets)
+        self.assertIn(frozenset({1, 2}), Sets)
+        self.assertNotIn({1, 3}, Sets)
+        self.assertNotIn(frozenset({1, 3}), Sets)
+        for enum_class in Magic, BytesMagic:
+            self.assertIn(bytearray(b'\x89PNG'), enum_class)
+            self.assertNotIn(bytearray(b'GIF8'), enum_class)
+            self.assertIs(enum_class(bytearray(b'\x89PNG')), enum_class.PNG)
+
 
 class TestOrder(unittest.TestCase):
     "test usage of the `_order_` attribute"