bpo-37479: on Enum subclasses with mixins, __format__ uses overridden __str__ (GH-14545)
* bpo-37479: on Enum subclasses with mixins, __format__ uses overridden __str__
diff --git a/Lib/enum.py b/Lib/enum.py
index 403f747..69a7f49 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -622,8 +622,9 @@
# we can get strange results with the Enum name showing up instead of
# the value
- # pure Enum branch
- if self._member_type_ is object:
+ # pure Enum branch, or branch with __str__ explicitly overridden
+ str_overridden = type(self).__str__ != Enum.__str__
+ if self._member_type_ is object or str_overridden:
cls = str
val = str(self)
# mix-in branch
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 47081cf..fcfa7d9 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -445,12 +445,63 @@
self.assertEqual('{:<20}'.format(Season.SPRING),
'{:<20}'.format(str(Season.SPRING)))
- def test_format_enum_custom(self):
+ def test_str_override_enum(self):
+ class EnumWithStrOverrides(Enum):
+ one = auto()
+ two = auto()
+
+ def __str__(self):
+ return 'Str!'
+ self.assertEqual(str(EnumWithStrOverrides.one), 'Str!')
+ self.assertEqual('{}'.format(EnumWithStrOverrides.one), 'Str!')
+
+ def test_format_override_enum(self):
+ class EnumWithFormatOverride(Enum):
+ one = 1.0
+ two = 2.0
+ def __format__(self, spec):
+ return 'Format!!'
+ self.assertEqual(str(EnumWithFormatOverride.one), 'EnumWithFormatOverride.one')
+ self.assertEqual('{}'.format(EnumWithFormatOverride.one), 'Format!!')
+
+ def test_str_and_format_override_enum(self):
+ class EnumWithStrFormatOverrides(Enum):
+ one = auto()
+ two = auto()
+ def __str__(self):
+ return 'Str!'
+ def __format__(self, spec):
+ return 'Format!'
+ self.assertEqual(str(EnumWithStrFormatOverrides.one), 'Str!')
+ self.assertEqual('{}'.format(EnumWithStrFormatOverrides.one), 'Format!')
+
+ def test_str_override_mixin(self):
+ class MixinEnumWithStrOverride(float, Enum):
+ one = 1.0
+ two = 2.0
+ def __str__(self):
+ return 'Overridden!'
+ self.assertEqual(str(MixinEnumWithStrOverride.one), 'Overridden!')
+ self.assertEqual('{}'.format(MixinEnumWithStrOverride.one), 'Overridden!')
+
+ def test_str_and_format_override_mixin(self):
+ class MixinWithStrFormatOverrides(float, Enum):
+ one = 1.0
+ two = 2.0
+ def __str__(self):
+ return 'Str!'
+ def __format__(self, spec):
+ return 'Format!'
+ self.assertEqual(str(MixinWithStrFormatOverrides.one), 'Str!')
+ self.assertEqual('{}'.format(MixinWithStrFormatOverrides.one), 'Format!')
+
+ def test_format_override_mixin(self):
class TestFloat(float, Enum):
one = 1.0
two = 2.0
def __format__(self, spec):
return 'TestFloat success!'
+ self.assertEqual(str(TestFloat.one), 'TestFloat.one')
self.assertEqual('{}'.format(TestFloat.one), 'TestFloat success!')
def assertFormatIsValue(self, spec, member):