[Python-checkins] gh-93464: [Enum] fix auto() failure during multiple assignment (GH-99148)
ethanfurman
webhook-mailer at python.org
Sat Nov 5 21:01:20 EDT 2022
https://github.com/python/cpython/commit/8feb7ab77c80968a6de6079299a39b0494b1701b
commit: 8feb7ab77c80968a6de6079299a39b0494b1701b
branch: main
author: Ethan Furman <ethan at stoneleaf.us>
committer: ethanfurman <ethan at stoneleaf.us>
date: 2022-11-05T18:01:08-07:00
summary:
gh-93464: [Enum] fix auto() failure during multiple assignment (GH-99148)
* fix auto() failure during multiple assignment
i.e. `ONE = auto(), 'text'` will now have `ONE' with the value of `(1,
'text')`. Before it would have been `(<an auto instance>, 'text')`
files:
A Misc/NEWS.d/next/Library/2022-11-05-23-16-15.gh-issue-93464.ucd4vP.rst
M Doc/library/enum.rst
M Lib/enum.py
M Lib/test/test_enum.py
diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst
index dcced28b8508..d481f058fbec 100644
--- a/Doc/library/enum.rst
+++ b/Doc/library/enum.rst
@@ -242,8 +242,8 @@ Data Types
Member values can be anything: :class:`int`, :class:`str`, etc.. If
the exact value is unimportant you may use :class:`auto` instances and an
- appropriate value will be chosen for you. Care must be taken if you mix
- :class:`auto` with other values.
+ appropriate value will be chosen for you. See :class:`auto` for the
+ details.
.. attribute:: Enum._ignore_
@@ -778,7 +778,16 @@ Utilities and Decorators
For *Enum* and *IntEnum* that appropriate value will be the last value plus
one; for *Flag* and *IntFlag* it will be the first power-of-two greater
than the last value; for *StrEnum* it will be the lower-cased version of the
- member's name.
+ member's name. Care must be taken if mixing *auto()* with manually specified
+ values.
+
+ *auto* instances are only resolved when at the top level of an assignment:
+
+ * ``FIRST = auto()`` will work (auto() is replaced with ``1``);
+ * ``SECOND = auto(), -2`` will work (auto is replaced with ``2``, so ``2, -2`` is
+ used to create the ``SECOND`` enum member;
+ * ``THREE = [auto(), -3]`` will *not* work (``<auto instance>, -3`` is used to
+ create the ``THREE`` enum member)
``_generate_next_value_`` can be overridden to customize the values used by
*auto*.
diff --git a/Lib/enum.py b/Lib/enum.py
index a66c344dbc3d..c1ccf53dc639 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -171,7 +171,8 @@ class auto:
"""
Instances are replaced with an appropriate value in Enum class suites.
"""
- value = _auto_null
+ def __init__(self, value=_auto_null):
+ self.value = value
def __repr__(self):
return "auto(%r)" % self.value
@@ -427,15 +428,31 @@ def __setitem__(self, key, value):
elif isinstance(value, member):
# unwrap value here -- it will become a member
value = value.value
+ non_auto_store = True
+ single = False
if isinstance(value, auto):
- if value.value == _auto_null:
- value.value = self._generate_next_value(
- key, 1, len(self._member_names), self._last_values[:],
- )
- self._auto_called = True
- value = value.value
+ single = True
+ value = (value, )
+ if isinstance(value, tuple):
+ auto_valued = []
+ for v in value:
+ if isinstance(v, auto):
+ non_auto_store = False
+ if v.value == _auto_null:
+ v.value = self._generate_next_value(
+ key, 1, len(self._member_names), self._last_values[:],
+ )
+ self._auto_called = True
+ v = v.value
+ self._last_values.append(v)
+ auto_valued.append(v)
+ if single:
+ value = auto_valued[0]
+ else:
+ value = tuple(auto_valued)
self._member_names[key] = None
- self._last_values.append(value)
+ if non_auto_store:
+ self._last_values.append(value)
super().__setitem__(key, value)
def update(self, members, **more_members):
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index f50017d916f5..38b1d7c77146 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -4116,6 +4116,50 @@ class Dupes(Enum):
third = auto()
self.assertEqual([Dupes.first, Dupes.second, Dupes.third], list(Dupes))
+ def test_multiple_auto_on_line(self):
+ class Huh(Enum):
+ ONE = auto()
+ TWO = auto(), auto()
+ THREE = auto(), auto(), auto()
+ self.assertEqual(Huh.ONE.value, 1)
+ self.assertEqual(Huh.TWO.value, (2, 3))
+ self.assertEqual(Huh.THREE.value, (4, 5, 6))
+ #
+ class Hah(Enum):
+ def __new__(cls, value, abbr=None):
+ member = object.__new__(cls)
+ member._value_ = value
+ member.abbr = abbr or value[:3].lower()
+ return member
+ def _generate_next_value_(name, start, count, last):
+ return name
+ #
+ MONDAY = auto()
+ TUESDAY = auto()
+ WEDNESDAY = auto(), 'WED'
+ THURSDAY = auto(), 'Thu'
+ FRIDAY = auto()
+ self.assertEqual(Hah.MONDAY.value, 'MONDAY')
+ self.assertEqual(Hah.MONDAY.abbr, 'mon')
+ self.assertEqual(Hah.TUESDAY.value, 'TUESDAY')
+ self.assertEqual(Hah.TUESDAY.abbr, 'tue')
+ self.assertEqual(Hah.WEDNESDAY.value, 'WEDNESDAY')
+ self.assertEqual(Hah.WEDNESDAY.abbr, 'WED')
+ self.assertEqual(Hah.THURSDAY.value, 'THURSDAY')
+ self.assertEqual(Hah.THURSDAY.abbr, 'Thu')
+ self.assertEqual(Hah.FRIDAY.value, 'FRIDAY')
+ self.assertEqual(Hah.FRIDAY.abbr, 'fri')
+ #
+ class Huh(Enum):
+ def _generate_next_value_(name, start, count, last):
+ return count+1
+ ONE = auto()
+ TWO = auto(), auto()
+ THREE = auto(), auto(), auto()
+ self.assertEqual(Huh.ONE.value, 1)
+ self.assertEqual(Huh.TWO.value, (2, 2))
+ self.assertEqual(Huh.THREE.value, (3, 3, 3))
+
class TestEnumTypeSubclassing(unittest.TestCase):
pass
diff --git a/Misc/NEWS.d/next/Library/2022-11-05-23-16-15.gh-issue-93464.ucd4vP.rst b/Misc/NEWS.d/next/Library/2022-11-05-23-16-15.gh-issue-93464.ucd4vP.rst
new file mode 100644
index 000000000000..6393ec614353
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-11-05-23-16-15.gh-issue-93464.ucd4vP.rst
@@ -0,0 +1 @@
+``enum.auto()`` is now correctly activated when combined with other assignment values. E.g. ``ONE = auto(), 'some text'`` will now evaluate as ``(1, 'some text')``.
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