[Python-checkins] gh-94943: [Enum] improve repr() when inheriting from a dataclass (GH-99740)
ethanfurman
webhook-mailer at python.org
Tue Dec 6 16:44:03 EST 2022
https://github.com/python/cpython/commit/679efbb080242fc5be63ad873968f05faeef889f
commit: 679efbb080242fc5be63ad873968f05faeef889f
branch: main
author: Ethan Furman <ethan at stoneleaf.us>
committer: ethanfurman <ethan at stoneleaf.us>
date: 2022-12-06T13:43:41-08:00
summary:
gh-94943: [Enum] improve repr() when inheriting from a dataclass (GH-99740)
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach at Gerlach.CAM>
files:
A Misc/NEWS.d/next/Library/2022-11-23-23-58-45.gh-issue-94943.Oog0Zo.rst
M Doc/howto/enum.rst
M Doc/library/enum.rst
M Lib/enum.py
M Lib/test/test_enum.py
diff --git a/Doc/howto/enum.rst b/Doc/howto/enum.rst
index 98d9f4febe2d..3155c6cb977b 100644
--- a/Doc/howto/enum.rst
+++ b/Doc/howto/enum.rst
@@ -459,6 +459,31 @@ sense to allow sharing some common behavior between a group of enumerations.
(See `OrderedEnum`_ for an example.)
+.. _enum-dataclass-support:
+
+Dataclass support
+-----------------
+
+When inheriting from a :class:`~dataclasses.dataclass`,
+the :meth:`~Enum.__repr__` omits the inherited class' name. For example::
+
+ >>> @dataclass
+ ... class CreatureDataMixin:
+ ... size: str
+ ... legs: int
+ ... tail: bool = field(repr=False, default=True)
+ ...
+ >>> class Creature(CreatureDataMixin, Enum):
+ ... BEETLE = 'small', 6
+ ... DOG = 'medium', 4
+ ...
+ >>> Creature.DOG
+ <Creature.DOG: size='medium', legs=4>
+
+Use the :func:`!dataclass` argument ``repr=False``
+to use the standard :func:`repr`.
+
+
Pickling
--------
diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst
index 208aecf11c80..f8875440baf5 100644
--- a/Doc/library/enum.rst
+++ b/Doc/library/enum.rst
@@ -389,6 +389,8 @@ Data Types
Using :class:`auto` with :class:`Enum` results in integers of increasing value,
starting with ``1``.
+ .. versionchanged:: 3.12 Added :ref:`enum-dataclass-support`
+
.. class:: IntEnum
diff --git a/Lib/enum.py b/Lib/enum.py
index 1b683c702d59..f07b821f1a60 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -955,7 +955,15 @@ def _find_data_repr_(mcls, class_name, bases):
return base._value_repr_
elif '__repr__' in base.__dict__:
# this is our data repr
- return base.__dict__['__repr__']
+ # double-check if a dataclass with a default __repr__
+ if (
+ '__dataclass_fields__' in base.__dict__
+ and '__dataclass_params__' in base.__dict__
+ and base.__dict__['__dataclass_params__'].repr
+ ):
+ return _dataclass_repr
+ else:
+ return base.__dict__['__repr__']
return None
@classmethod
@@ -1551,6 +1559,14 @@ def _power_of_two(value):
return False
return value == 2 ** _high_bit(value)
+def _dataclass_repr(self):
+ dcf = self.__dataclass_fields__
+ return ', '.join(
+ '%s=%r' % (k, getattr(self, k))
+ for k in dcf.keys()
+ if dcf[k].repr
+ )
+
def global_enum_repr(self):
"""
use module.enum_name instead of class.enum_name
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index b6082cf02b18..146ef39ca384 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -2717,17 +2717,67 @@ def upper(self):
def test_repr_with_dataclass(self):
"ensure dataclass-mixin has correct repr()"
- from dataclasses import dataclass
- @dataclass
+ #
+ # check overridden dataclass __repr__ is used
+ #
+ from dataclasses import dataclass, field
+ @dataclass(repr=False)
class Foo:
__qualname__ = 'Foo'
a: int
+ def __repr__(self):
+ return 'ha hah!'
class Entries(Foo, Enum):
ENTRY1 = 1
self.assertTrue(isinstance(Entries.ENTRY1, Foo))
self.assertTrue(Entries._member_type_ is Foo, Entries._member_type_)
self.assertTrue(Entries.ENTRY1.value == Foo(1), Entries.ENTRY1.value)
- self.assertEqual(repr(Entries.ENTRY1), '<Entries.ENTRY1: Foo(a=1)>')
+ self.assertEqual(repr(Entries.ENTRY1), '<Entries.ENTRY1: ha hah!>')
+ #
+ # check auto-generated dataclass __repr__ is not used
+ #
+ @dataclass
+ class CreatureDataMixin:
+ __qualname__ = 'CreatureDataMixin'
+ size: str
+ legs: int
+ tail: bool = field(repr=False, default=True)
+ class Creature(CreatureDataMixin, Enum):
+ __qualname__ = 'Creature'
+ BEETLE = ('small', 6)
+ DOG = ('medium', 4)
+ self.assertEqual(repr(Creature.DOG), "<Creature.DOG: size='medium', legs=4>")
+ #
+ # check inherited repr used
+ #
+ class Huh:
+ def __repr__(self):
+ return 'inherited'
+ @dataclass(repr=False)
+ class CreatureDataMixin(Huh):
+ __qualname__ = 'CreatureDataMixin'
+ size: str
+ legs: int
+ tail: bool = field(repr=False, default=True)
+ class Creature(CreatureDataMixin, Enum):
+ __qualname__ = 'Creature'
+ BEETLE = ('small', 6)
+ DOG = ('medium', 4)
+ self.assertEqual(repr(Creature.DOG), "<Creature.DOG: inherited>")
+ #
+ # check default object.__repr__ used if nothing provided
+ #
+ @dataclass(repr=False)
+ class CreatureDataMixin:
+ __qualname__ = 'CreatureDataMixin'
+ size: str
+ legs: int
+ tail: bool = field(repr=False, default=True)
+ class Creature(CreatureDataMixin, Enum):
+ __qualname__ = 'Creature'
+ BEETLE = ('small', 6)
+ DOG = ('medium', 4)
+ self.assertRegex(repr(Creature.DOG), "<Creature.DOG: .*CreatureDataMixin object at .*>")
def test_repr_with_init_data_type_mixin(self):
# non-data_type is a mixin that doesn't define __new__
diff --git a/Misc/NEWS.d/next/Library/2022-11-23-23-58-45.gh-issue-94943.Oog0Zo.rst b/Misc/NEWS.d/next/Library/2022-11-23-23-58-45.gh-issue-94943.Oog0Zo.rst
new file mode 100644
index 000000000000..ed4754e49bd2
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-11-23-23-58-45.gh-issue-94943.Oog0Zo.rst
@@ -0,0 +1,5 @@
+Add :ref:`enum-dataclass-support` to the
+:class:`~enum.Enum` :meth:`~enum.Enum.__repr__`.
+When inheriting from a :class:`~dataclasses.dataclass`,
+only show the field names in the value section of the member :func:`repr`,
+and not the dataclass' class name.
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