[Python-checkins] [3.11] gh-105332: [Enum] Fix unpickling flags in edge-cases (GH-105348) (GH-105519)
ethanfurman
webhook-mailer at python.org
Thu Jun 8 21:02:19 EDT 2023
https://github.com/python/cpython/commit/fed1b5a198c20b4b94a594248c88b3bcac9937eb
commit: fed1b5a198c20b4b94a594248c88b3bcac9937eb
branch: 3.11
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: ethanfurman <ethan at stoneleaf.us>
date: 2023-06-08T18:02:12-07:00
summary:
[3.11] gh-105332: [Enum] Fix unpickling flags in edge-cases (GH-105348) (GH-105519)
* revert enum pickling from by-name to by-value
(cherry picked from commit 4ff5690e591b7d11cf11e34bf61004e2ea58ab3c)
Co-authored-by: Nikita Sobolev <mail at sobolevn.me>
Co-authored-by: Ethan Furman <ethan at stoneleaf.us>
files:
A Misc/NEWS.d/next/Library/2023-06-06-11-50-33.gh-issue-105332.tmpgRA.rst
M Doc/howto/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 55f0dfb4c48c3..e9049440d2368 100644
--- a/Doc/howto/enum.rst
+++ b/Doc/howto/enum.rst
@@ -484,7 +484,16 @@ from that module.
nested in other classes.
It is possible to modify how enum members are pickled/unpickled by defining
-:meth:`__reduce_ex__` in the enumeration class.
+:meth:`__reduce_ex__` in the enumeration class. The default method is by-value,
+but enums with complicated values may want to use by-name::
+
+ >>> class MyEnum(Enum):
+ ... __reduce_ex__ = enum.pickle_by_enum_name
+
+.. note::
+
+ Using by-name for flags is not recommended, as unnamed aliases will
+ not unpickle.
Functional API
diff --git a/Lib/enum.py b/Lib/enum.py
index 45e3cd0b95d9b..f07fb37852e68 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -12,6 +12,7 @@
'FlagBoundary', 'STRICT', 'CONFORM', 'EJECT', 'KEEP',
'global_flag_repr', 'global_enum_repr', 'global_str', 'global_enum',
'EnumCheck', 'CONTINUOUS', 'NAMED_FLAGS', 'UNIQUE',
+ 'pickle_by_global_name', 'pickle_by_enum_name',
]
@@ -918,7 +919,6 @@ def _convert_(cls, name, module, filter, source=None, *, boundary=None, as_globa
body['__module__'] = module
tmp_cls = type(name, (object, ), body)
cls = _simple_enum(etype=cls, boundary=boundary or KEEP)(tmp_cls)
- cls.__reduce_ex__ = _reduce_ex_by_global_name
if as_global:
global_enum(cls)
else:
@@ -1225,7 +1225,7 @@ def __hash__(self):
return hash(self._name_)
def __reduce_ex__(self, proto):
- return getattr, (self.__class__, self._name_)
+ return self.__class__, (self._value_, )
# enum.property is used to provide access to the `name` and
# `value` attributes of enum members while keeping some measure of
@@ -1291,8 +1291,14 @@ def _generate_next_value_(name, start, count, last_values):
return name.lower()
-def _reduce_ex_by_global_name(self, proto):
+def pickle_by_global_name(self, proto):
+ # should not be used with Flag-type enums
return self.name
+_reduce_ex_by_global_name = pickle_by_global_name
+
+def pickle_by_enum_name(self, proto):
+ # should not be used with Flag-type enums
+ return getattr, (self.__class__, self._name_)
class FlagBoundary(StrEnum):
"""
@@ -1314,23 +1320,6 @@ class Flag(Enum, boundary=STRICT):
Support for flags
"""
- def __reduce_ex__(self, proto):
- cls = self.__class__
- unknown = self._value_ & ~cls._flag_mask_
- member_value = self._value_ & cls._flag_mask_
- if unknown and member_value:
- return _or_, (cls(member_value), unknown)
- for val in _iter_bits_lsb(member_value):
- rest = member_value & ~val
- if rest:
- return _or_, (cls(rest), cls._value2member_map_.get(val))
- else:
- break
- if self._name_ is None:
- return cls, (self._value_,)
- else:
- return getattr, (cls, self._name_)
-
_numeric_repr_ = repr
def _generate_next_value_(name, start, count, last_values):
@@ -2047,7 +2036,6 @@ def _old_convert_(etype, name, module, filter, source=None, *, boundary=None):
# unless some values aren't comparable, in which case sort by name
members.sort(key=lambda t: t[0])
cls = etype(name, members, module=module, boundary=boundary or KEEP)
- cls.__reduce_ex__ = _reduce_ex_by_global_name
return cls
_stdlib_enums = IntEnum, StrEnum, IntFlag
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index f5cefa2f35202..50048253a8096 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -32,6 +32,11 @@ def load_tests(loader, tests, ignore):
'../../Doc/library/enum.rst',
optionflags=doctest.ELLIPSIS|doctest.NORMALIZE_WHITESPACE,
))
+ if os.path.exists('Doc/howto/enum.rst'):
+ tests.addTests(doctest.DocFileSuite(
+ '../../Doc/howto/enum.rst',
+ optionflags=doctest.ELLIPSIS|doctest.NORMALIZE_WHITESPACE,
+ ))
return tests
MODULE = __name__
@@ -67,6 +72,7 @@ class FlagStooges(Flag):
LARRY = 1
CURLY = 2
MOE = 4
+ BIG = 389
except Exception as exc:
FlagStooges = exc
@@ -75,17 +81,20 @@ class FlagStoogesWithZero(Flag):
LARRY = 1
CURLY = 2
MOE = 4
+ BIG = 389
class IntFlagStooges(IntFlag):
LARRY = 1
CURLY = 2
MOE = 4
+ BIG = 389
class IntFlagStoogesWithZero(IntFlag):
NOFLAG = 0
LARRY = 1
CURLY = 2
MOE = 4
+ BIG = 389
# for pickle test and subclass tests
class Name(StrEnum):
@@ -1860,7 +1869,6 @@ class NEI(NamedInt, Enum):
__qualname__ = 'NEI'
x = ('the-x', 1)
y = ('the-y', 2)
-
self.assertIs(NEI.__new__, Enum.__new__)
self.assertEqual(repr(NEI.x + NEI.y), "NamedInt('(the-x + the-y)', 3)")
globals()['NamedInt'] = NamedInt
@@ -1868,6 +1876,10 @@ class NEI(NamedInt, Enum):
NI5 = NamedInt('test', 5)
self.assertEqual(NI5, 5)
self.assertEqual(NEI.y.value, 2)
+ with self.assertRaisesRegex(TypeError, "name and value must be specified"):
+ test_pickle_dump_load(self.assertIs, NEI.y)
+ # fix pickle support and try again
+ NEI.__reduce_ex__ = enum.pickle_by_enum_name
test_pickle_dump_load(self.assertIs, NEI.y)
test_pickle_dump_load(self.assertIs, NEI)
@@ -3120,11 +3132,17 @@ def test_pickle(self):
test_pickle_dump_load(self.assertEqual,
FlagStooges.CURLY&~FlagStooges.CURLY)
test_pickle_dump_load(self.assertIs, FlagStooges)
+ test_pickle_dump_load(self.assertEqual, FlagStooges.BIG)
+ test_pickle_dump_load(self.assertEqual,
+ FlagStooges.CURLY|FlagStooges.BIG)
test_pickle_dump_load(self.assertIs, FlagStoogesWithZero.CURLY)
test_pickle_dump_load(self.assertEqual,
FlagStoogesWithZero.CURLY|FlagStoogesWithZero.MOE)
test_pickle_dump_load(self.assertIs, FlagStoogesWithZero.NOFLAG)
+ test_pickle_dump_load(self.assertEqual, FlagStoogesWithZero.BIG)
+ test_pickle_dump_load(self.assertEqual,
+ FlagStoogesWithZero.CURLY|FlagStoogesWithZero.BIG)
test_pickle_dump_load(self.assertIs, IntFlagStooges.CURLY)
test_pickle_dump_load(self.assertEqual,
@@ -3134,11 +3152,19 @@ def test_pickle(self):
test_pickle_dump_load(self.assertEqual, IntFlagStooges(0))
test_pickle_dump_load(self.assertEqual, IntFlagStooges(0x30))
test_pickle_dump_load(self.assertIs, IntFlagStooges)
+ test_pickle_dump_load(self.assertEqual, IntFlagStooges.BIG)
+ test_pickle_dump_load(self.assertEqual, IntFlagStooges.BIG|1)
+ test_pickle_dump_load(self.assertEqual,
+ IntFlagStooges.CURLY|IntFlagStooges.BIG)
test_pickle_dump_load(self.assertIs, IntFlagStoogesWithZero.CURLY)
test_pickle_dump_load(self.assertEqual,
IntFlagStoogesWithZero.CURLY|IntFlagStoogesWithZero.MOE)
test_pickle_dump_load(self.assertIs, IntFlagStoogesWithZero.NOFLAG)
+ test_pickle_dump_load(self.assertEqual, IntFlagStoogesWithZero.BIG)
+ test_pickle_dump_load(self.assertEqual, IntFlagStoogesWithZero.BIG|1)
+ test_pickle_dump_load(self.assertEqual,
+ IntFlagStoogesWithZero.CURLY|IntFlagStoogesWithZero.BIG)
@unittest.skipIf(
python_version >= (3, 12),
diff --git a/Misc/NEWS.d/next/Library/2023-06-06-11-50-33.gh-issue-105332.tmpgRA.rst b/Misc/NEWS.d/next/Library/2023-06-06-11-50-33.gh-issue-105332.tmpgRA.rst
new file mode 100644
index 0000000000000..31b6855a6ebfa
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-06-06-11-50-33.gh-issue-105332.tmpgRA.rst
@@ -0,0 +1 @@
+Revert pickling method from by-name back to by-value.
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