bpo-39728: Enum: fix duplicate `ValueError` (GH-22277)
fix default `_missing_` to return `None` instead of raising a `ValueError`
Co-authored-by: Andrey Darascheka <andrei.daraschenka@leverx.com>
diff --git a/Lib/enum.py b/Lib/enum.py
index 0c2cf56..060b2a0 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -629,7 +629,7 @@
@classmethod
def _missing_(cls, value):
- raise ValueError("%r is not a valid %s" % (value, cls.__qualname__))
+ return None
def __repr__(self):
return "<%s.%s: %r>" % (
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 2fcd047..5d72d82 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -1845,6 +1845,18 @@
third = auto()
self.assertEqual([Dupes.first, Dupes.second, Dupes.third], list(Dupes))
+ def test_default_missing(self):
+ class Color(Enum):
+ RED = 1
+ GREEN = 2
+ BLUE = 3
+ try:
+ Color(7)
+ except ValueError as exc:
+ self.assertTrue(exc.__context__ is None)
+ else:
+ raise Exception('Exception not raised.')
+
def test_missing(self):
class Color(Enum):
red = 1
@@ -1863,7 +1875,12 @@
# trigger not found
return None
self.assertIs(Color('three'), Color.blue)
- self.assertRaises(ValueError, Color, 7)
+ try:
+ Color(7)
+ except ValueError as exc:
+ self.assertTrue(exc.__context__ is None)
+ else:
+ raise Exception('Exception not raised.')
try:
Color('bad return')
except TypeError as exc: