gh-114149: [Enum] fix tuple subclass handling when using custom __new__ (GH-114160)

Author: ethanfurman

Lib/enum.py

@@ -250,7 +250,7 @@ def __set_name__(self, enum_class, member_name):
         delattr(enum_class, member_name)
         # second step: create member based on enum_class
         value = self.value
-        if not isinstance(value, tuple):
+        if type(value) is not tuple:
             args = (value, )
         else:
             args = value
@@ -1777,7 +1777,7 @@ def convert_class(cls):
                 else:
                     # create the member
                     if use_args:
-                        if not isinstance(value, tuple):
+                        if type(value) is not tuple:
                             value = (value, )
                         member = new_member(enum_class, *value)
                         value = value[0]
@@ -1826,7 +1826,7 @@ def convert_class(cls):
                 else:
                     # create the member
                     if use_args:
-                        if not isinstance(value, tuple):
+                        if type(value) is not tuple:
                             value = (value, )
                         member = new_member(enum_class, *value)
                         value = value[0]

Lib/test/test_enum.py

@@ -3201,6 +3201,22 @@ class NTEnum(Enum):
                 [x.value for x in NTEnum],
                 [TTuple(id=0, a=0, blist=[]), TTuple(id=1, a=2, blist=[4]), TTuple(id=2, a=4, blist=[0, 1, 2])],
                 )
+        #
+        class NTDEnum(Enum):
+            def __new__(cls, t_value):
+                member = object.__new__(cls)
+                member._value_ = t_value[0]
+                member.id = t_value[0]
+                member.a = t_value[1]
+                member.blist = t_value[2]
+                return member
+            NONE = TTuple(0, 0, [])
+            A = TTuple(1, 2, [4])
+            B = TTuple(2, 4, [0, 1, 2])
+        self.assertEqual(repr(NTDEnum.NONE), "<NTDEnum.NONE: 0>")
+        self.assertEqual(NTDEnum.NONE.id, 0)
+        self.assertEqual(NTDEnum.A.a, 2)
+        self.assertEqual(NTDEnum.B.blist, [0, 1 ,2])
 
     def test_flag_with_custom_new(self):
         class FlagFromChar(IntFlag):

Misc/NEWS.d/next/Library/2024-01-16-15-59-06.gh-issue-114149.LJ8IPm.rst

@@ -0,0 +1 @@
+Enum: correctly handle tuple subclasses in custom ``__new__``.