bpo-41816: `StrEnum.__str__` is `str.__str__` (GH-22362)
use `str.__str__` for `StrEnum` so that `str(StrEnum.member)` is the same as directly accessing the string value of the `StrEnum` member
diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst
index 3e9b1f9..118002b 100644
--- a/Doc/library/enum.rst
+++ b/Doc/library/enum.rst
@@ -622,6 +622,11 @@
Before :class:`StrEnum`, ``Directions.NORTH`` would have been the :class:`tuple`
``('north',)``.
+.. note::
+
+ Unlike other Enum's, ``str(StrEnum.member)`` will return the value of the
+ member instead of the usual ``"EnumClass.member"``.
+
.. versionadded:: 3.10
@@ -1243,3 +1248,13 @@
>>> Color(7) # not named combination
<Color.CYAN|MAGENTA|BLUE|YELLOW|GREEN|RED: 7>
+``StrEnum`` and :meth:`str.__str__`
+"""""""""""""""""""""""""""""""""""
+
+An important difference between :class:`StrEnum` and other Enums is the
+:meth:`__str__` method; because :class:`StrEnum` members are strings, some
+parts of Python will read the string data directly, while others will call
+:meth:`str()`. To make those two operations have the same result,
+:meth:`StrEnum.__str__` will be the same as :meth:`str.__str__` so that
+``str(StrEnum.member) == StrEnum.member`` is true.
+
diff --git a/Lib/enum.py b/Lib/enum.py
index 589b17f..40ff25b 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -718,6 +718,8 @@
member._value_ = value
return member
+ __str__ = str.__str__
+
def _reduce_ex_by_name(self, proto):
return self.name
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 8e84d92..3431040 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -2036,6 +2036,37 @@
two = '2'
three = b'3', 'ascii'
four = b'4', 'latin1', 'strict'
+ self.assertEqual(GoodStrEnum.one, '1')
+ self.assertEqual(str(GoodStrEnum.one), '1')
+ self.assertEqual(GoodStrEnum.one, str(GoodStrEnum.one))
+ self.assertEqual(GoodStrEnum.one, '{}'.format(GoodStrEnum.one))
+ #
+ class DumbMixin:
+ def __str__(self):
+ return "don't do this"
+ class DumbStrEnum(DumbMixin, StrEnum):
+ five = '5'
+ six = '6'
+ seven = '7'
+ self.assertEqual(DumbStrEnum.seven, '7')
+ self.assertEqual(str(DumbStrEnum.seven), "don't do this")
+ #
+ class EnumMixin(Enum):
+ def hello(self):
+ print('hello from %s' % (self, ))
+ class HelloEnum(EnumMixin, StrEnum):
+ eight = '8'
+ self.assertEqual(HelloEnum.eight, '8')
+ self.assertEqual(HelloEnum.eight, str(HelloEnum.eight))
+ #
+ class GoodbyeMixin:
+ def goodbye(self):
+ print('%s wishes you a fond farewell')
+ class GoodbyeEnum(GoodbyeMixin, EnumMixin, StrEnum):
+ nine = '9'
+ self.assertEqual(GoodbyeEnum.nine, '9')
+ self.assertEqual(GoodbyeEnum.nine, str(GoodbyeEnum.nine))
+ #
with self.assertRaisesRegex(TypeError, '1 is not a string'):
class FirstFailedStrEnum(StrEnum):
one = 1