[Python-checkins] cpython (merge 3.6 -> default): issue23591: fix flag decomposition and repr
ethan.furman
python-checkins at python.org
Sun Sep 18 16:16:29 EDT 2016
https://hg.python.org/cpython/rev/7372c042e9a1
changeset: 103929:7372c042e9a1
parent: 103926:911070065e38
parent: 103928:b56290a80ff7
user: Ethan Furman <ethan at stoneleaf.us>
date: Sun Sep 18 13:16:04 2016 -0700
summary:
issue23591: fix flag decomposition and repr
files:
Doc/library/enum.rst | 22 ++++
Lib/enum.py | 152 ++++++++++++++++++-----------
Lib/test/test_enum.py | 105 +++++++++++++++-----
3 files changed, 193 insertions(+), 86 deletions(-)
diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst
--- a/Doc/library/enum.rst
+++ b/Doc/library/enum.rst
@@ -674,6 +674,8 @@
... green = auto()
... white = red | blue | green
...
+ >>> Color.white
+ <Color.white: 7>
Giving a name to the "no flags set" condition does not change its boolean
value::
@@ -1068,3 +1070,23 @@
>>> dir(Planet.EARTH)
['__class__', '__doc__', '__module__', 'name', 'surface_gravity', 'value']
+
+Combining members of ``Flag``
+"""""""""""""""""""""""""""""
+
+If a combination of Flag members is not named, the :func:`repr` will include
+all named flags and all named combinations of flags that are in the value::
+
+ >>> class Color(Flag):
+ ... red = auto()
+ ... green = auto()
+ ... blue = auto()
+ ... magenta = red | blue
+ ... yellow = red | green
+ ... cyan = green | blue
+ ...
+ >>> Color(3) # named combination
+ <Color.yellow: 3>
+ >>> Color(7) # not named combination
+ <Color.cyan|magenta|blue|yellow|green|red: 7>
+
diff --git a/Lib/enum.py b/Lib/enum.py
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -1,7 +1,7 @@
import sys
from types import MappingProxyType, DynamicClassAttribute
from functools import reduce
-from operator import or_ as _or_
+from operator import or_ as _or_, and_ as _and_, xor, neg
# try _collections first to reduce startup cost
try:
@@ -47,11 +47,12 @@
cls.__reduce_ex__ = _break_on_call_reduce
cls.__module__ = '<unknown>'
+_auto_null = object()
class auto:
"""
Instances are replaced with an appropriate value in Enum class suites.
"""
- pass
+ value = _auto_null
class _EnumDict(dict):
@@ -77,7 +78,7 @@
"""
if _is_sunder(key):
if key not in (
- '_order_', '_create_pseudo_member_', '_decompose_',
+ '_order_', '_create_pseudo_member_',
'_generate_next_value_', '_missing_',
):
raise ValueError('_names_ are reserved for future Enum use')
@@ -94,7 +95,9 @@
# enum overwriting a descriptor?
raise TypeError('%r already defined as: %r' % (key, self[key]))
if isinstance(value, auto):
- value = self._generate_next_value(key, 1, len(self._member_names), self._last_values[:])
+ if value.value == _auto_null:
+ value.value = self._generate_next_value(key, 1, len(self._member_names), self._last_values[:])
+ value = value.value
self._member_names.append(key)
self._last_values.append(value)
super().__setitem__(key, value)
@@ -658,7 +661,7 @@
try:
high_bit = _high_bit(last_value)
break
- except TypeError:
+ except Exception:
raise TypeError('Invalid Flag value: %r' % last_value) from None
return 2 ** (high_bit+1)
@@ -668,61 +671,38 @@
if value < 0:
value = ~value
possible_member = cls._create_pseudo_member_(value)
- for member in possible_member._decompose_():
- if member._name_ is None and member._value_ != 0:
- raise ValueError('%r is not a valid %s' % (original_value, cls.__name__))
if original_value < 0:
possible_member = ~possible_member
return possible_member
@classmethod
def _create_pseudo_member_(cls, value):
+ """
+ Create a composite member iff value contains only members.
+ """
pseudo_member = cls._value2member_map_.get(value, None)
if pseudo_member is None:
- # construct a non-singleton enum pseudo-member
+ # verify all bits are accounted for
+ _, extra_flags = _decompose(cls, value)
+ if extra_flags:
+ raise ValueError("%r is not a valid %s" % (value, cls.__name__))
+ # construct a singleton enum pseudo-member
pseudo_member = object.__new__(cls)
pseudo_member._name_ = None
pseudo_member._value_ = value
cls._value2member_map_[value] = pseudo_member
return pseudo_member
- def _decompose_(self):
- """Extract all members from the value."""
- value = self._value_
- members = []
- cls = self.__class__
- for member in sorted(cls, key=lambda m: m._value_, reverse=True):
- while _high_bit(value) > _high_bit(member._value_):
- unknown = self._create_pseudo_member_(2 ** _high_bit(value))
- members.append(unknown)
- value &= ~unknown._value_
- if (
- (value & member._value_ == member._value_)
- and (member._value_ or not members)
- ):
- value &= ~member._value_
- members.append(member)
- if not members or value:
- members.append(self._create_pseudo_member_(value))
- members = list(members)
- return members
-
def __contains__(self, other):
if not isinstance(other, self.__class__):
return NotImplemented
return other._value_ & self._value_ == other._value_
- def __iter__(self):
- if self.value == 0:
- return iter([])
- else:
- return iter(self._decompose_())
-
def __repr__(self):
cls = self.__class__
if self._name_ is not None:
return '<%s.%s: %r>' % (cls.__name__, self._name_, self._value_)
- members = self._decompose_()
+ members, uncovered = _decompose(cls, self._value_)
return '<%s.%s: %r>' % (
cls.__name__,
'|'.join([str(m._name_ or m._value_) for m in members]),
@@ -733,7 +713,7 @@
cls = self.__class__
if self._name_ is not None:
return '%s.%s' % (cls.__name__, self._name_)
- members = self._decompose_()
+ members, uncovered = _decompose(cls, self._value_)
if len(members) == 1 and members[0]._name_ is None:
return '%s.%r' % (cls.__name__, members[0]._value_)
else:
@@ -761,8 +741,11 @@
return self.__class__(self._value_ ^ other._value_)
def __invert__(self):
- members = self._decompose_()
- inverted_members = [m for m in self.__class__ if m not in members and not m._value_ & self._value_]
+ members, uncovered = _decompose(self.__class__, self._value_)
+ inverted_members = [
+ m for m in self.__class__
+ if m not in members and not m._value_ & self._value_
+ ]
inverted = reduce(_or_, inverted_members, self.__class__(0))
return self.__class__(inverted)
@@ -771,25 +754,45 @@
"""Support for integer-based Flags"""
@classmethod
+ def _missing_(cls, value):
+ if not isinstance(value, int):
+ raise ValueError("%r is not a valid %s" % (value, cls.__name__))
+ new_member = cls._create_pseudo_member_(value)
+ return new_member
+
+ @classmethod
def _create_pseudo_member_(cls, value):
pseudo_member = cls._value2member_map_.get(value, None)
if pseudo_member is None:
- # construct a non-singleton enum pseudo-member
- pseudo_member = int.__new__(cls, value)
- pseudo_member._name_ = None
- pseudo_member._value_ = value
- cls._value2member_map_[value] = pseudo_member
+ need_to_create = [value]
+ # get unaccounted for bits
+ _, extra_flags = _decompose(cls, value)
+ # timer = 10
+ while extra_flags:
+ # timer -= 1
+ bit = _high_bit(extra_flags)
+ flag_value = 2 ** bit
+ if (flag_value not in cls._value2member_map_ and
+ flag_value not in need_to_create
+ ):
+ need_to_create.append(flag_value)
+ if extra_flags == -flag_value:
+ extra_flags = 0
+ else:
+ extra_flags ^= flag_value
+ for value in reversed(need_to_create):
+ # construct singleton pseudo-members
+ pseudo_member = int.__new__(cls, value)
+ pseudo_member._name_ = None
+ pseudo_member._value_ = value
+ cls._value2member_map_[value] = pseudo_member
return pseudo_member
- @classmethod
- def _missing_(cls, value):
- possible_member = cls._create_pseudo_member_(value)
- return possible_member
-
def __or__(self, other):
if not isinstance(other, (self.__class__, int)):
return NotImplemented
- return self.__class__(self._value_ | self.__class__(other)._value_)
+ result = self.__class__(self._value_ | self.__class__(other)._value_)
+ return result
def __and__(self, other):
if not isinstance(other, (self.__class__, int)):
@@ -806,17 +809,13 @@
__rxor__ = __xor__
def __invert__(self):
- # members = self._decompose_()
- # inverted_members = [m for m in self.__class__ if m not in members and not m._value_ & self._value_]
- # inverted = reduce(_or_, inverted_members, self.__class__(0))
- return self.__class__(~self._value_)
-
-
+ result = self.__class__(~self._value_)
+ return result
def _high_bit(value):
"""returns index of highest bit, or -1 if value is zero or negative"""
- return value.bit_length() - 1 if value > 0 else -1
+ return value.bit_length() - 1
def unique(enumeration):
"""Class decorator for enumerations ensuring unique member values."""
@@ -830,3 +829,40 @@
raise ValueError('duplicate values found in %r: %s' %
(enumeration, alias_details))
return enumeration
+
+def _decompose(flag, value):
+ """Extract all members from the value."""
+ # _decompose is only called if the value is not named
+ not_covered = value
+ negative = value < 0
+ if negative:
+ # only check for named flags
+ flags_to_check = [
+ (m, v)
+ for v, m in flag._value2member_map_.items()
+ if m.name is not None
+ ]
+ else:
+ # check for named flags and powers-of-two flags
+ flags_to_check = [
+ (m, v)
+ for v, m in flag._value2member_map_.items()
+ if m.name is not None or _power_of_two(v)
+ ]
+ members = []
+ for member, member_value in flags_to_check:
+ if member_value and member_value & value == member_value:
+ members.append(member)
+ not_covered &= ~member_value
+ if not members and value in flag._value2member_map_:
+ members.append(flag._value2member_map_[value])
+ members.sort(key=lambda m: m._value_, reverse=True)
+ if len(members) > 1 and members[0].value == value:
+ # we have the breakdown, don't need the value member itself
+ members.pop(0)
+ return members, not_covered
+
+def _power_of_two(value):
+ if value < 1:
+ return False
+ return value == 2 ** _high_bit(value)
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -1634,6 +1634,13 @@
self.assertEqual(Color.blue.value, 2)
self.assertEqual(Color.green.value, 3)
+ def test_duplicate_auto(self):
+ class Dupes(Enum):
+ first = primero = auto()
+ second = auto()
+ third = auto()
+ self.assertEqual([Dupes.first, Dupes.second, Dupes.third], list(Dupes))
+
class TestOrder(unittest.TestCase):
@@ -1731,7 +1738,7 @@
self.assertEqual(str(Open.AC), 'Open.AC')
self.assertEqual(str(Open.RO | Open.CE), 'Open.CE')
self.assertEqual(str(Open.WO | Open.CE), 'Open.CE|WO')
- self.assertEqual(str(~Open.RO), 'Open.CE|AC')
+ self.assertEqual(str(~Open.RO), 'Open.CE|AC|RW|WO')
self.assertEqual(str(~Open.WO), 'Open.CE|RW')
self.assertEqual(str(~Open.AC), 'Open.CE')
self.assertEqual(str(~(Open.RO | Open.CE)), 'Open.AC')
@@ -1758,7 +1765,7 @@
self.assertEqual(repr(Open.AC), '<Open.AC: 3>')
self.assertEqual(repr(Open.RO | Open.CE), '<Open.CE: 524288>')
self.assertEqual(repr(Open.WO | Open.CE), '<Open.CE|WO: 524289>')
- self.assertEqual(repr(~Open.RO), '<Open.CE|AC: 524291>')
+ self.assertEqual(repr(~Open.RO), '<Open.CE|AC|RW|WO: 524291>')
self.assertEqual(repr(~Open.WO), '<Open.CE|RW: 524290>')
self.assertEqual(repr(~Open.AC), '<Open.CE: 524288>')
self.assertEqual(repr(~(Open.RO | Open.CE)), '<Open.AC: 3>')
@@ -1949,6 +1956,33 @@
red = 'not an int'
blue = auto()
+ def test_cascading_failure(self):
+ class Bizarre(Flag):
+ c = 3
+ d = 4
+ f = 6
+ # Bizarre.c | Bizarre.d
+ self.assertRaisesRegex(ValueError, "5 is not a valid Bizarre", Bizarre, 5)
+ self.assertRaisesRegex(ValueError, "5 is not a valid Bizarre", Bizarre, 5)
+ self.assertRaisesRegex(ValueError, "2 is not a valid Bizarre", Bizarre, 2)
+ self.assertRaisesRegex(ValueError, "2 is not a valid Bizarre", Bizarre, 2)
+ self.assertRaisesRegex(ValueError, "1 is not a valid Bizarre", Bizarre, 1)
+ self.assertRaisesRegex(ValueError, "1 is not a valid Bizarre", Bizarre, 1)
+
+ def test_duplicate_auto(self):
+ class Dupes(Enum):
+ first = primero = auto()
+ second = auto()
+ third = auto()
+ self.assertEqual([Dupes.first, Dupes.second, Dupes.third], list(Dupes))
+
+ def test_bizarre(self):
+ class Bizarre(Flag):
+ b = 3
+ c = 4
+ d = 6
+ self.assertEqual(repr(Bizarre(7)), '<Bizarre.d|c|b: 7>')
+
class TestIntFlag(unittest.TestCase):
"""Tests of the IntFlags."""
@@ -1965,6 +1999,21 @@
AC = 3
CE = 1<<19
+ def test_type(self):
+ Perm = self.Perm
+ Open = self.Open
+ for f in Perm:
+ self.assertTrue(isinstance(f, Perm))
+ self.assertEqual(f, f.value)
+ self.assertTrue(isinstance(Perm.W | Perm.X, Perm))
+ self.assertEqual(Perm.W | Perm.X, 3)
+ for f in Open:
+ self.assertTrue(isinstance(f, Open))
+ self.assertEqual(f, f.value)
+ self.assertTrue(isinstance(Open.WO | Open.RW, Open))
+ self.assertEqual(Open.WO | Open.RW, 3)
+
+
def test_str(self):
Perm = self.Perm
self.assertEqual(str(Perm.R), 'Perm.R')
@@ -1975,14 +2024,14 @@
self.assertEqual(str(Perm.R | 8), 'Perm.8|R')
self.assertEqual(str(Perm(0)), 'Perm.0')
self.assertEqual(str(Perm(8)), 'Perm.8')
- self.assertEqual(str(~Perm.R), 'Perm.W|X|-8')
- self.assertEqual(str(~Perm.W), 'Perm.R|X|-8')
- self.assertEqual(str(~Perm.X), 'Perm.R|W|-8')
- self.assertEqual(str(~(Perm.R | Perm.W)), 'Perm.X|-8')
+ self.assertEqual(str(~Perm.R), 'Perm.W|X')
+ self.assertEqual(str(~Perm.W), 'Perm.R|X')
+ self.assertEqual(str(~Perm.X), 'Perm.R|W')
+ self.assertEqual(str(~(Perm.R | Perm.W)), 'Perm.X')
self.assertEqual(str(~(Perm.R | Perm.W | Perm.X)), 'Perm.-8')
- self.assertEqual(str(~(Perm.R | 8)), 'Perm.W|X|-16')
- self.assertEqual(str(Perm(~0)), 'Perm.R|W|X|-8')
- self.assertEqual(str(Perm(~8)), 'Perm.R|W|X|-16')
+ self.assertEqual(str(~(Perm.R | 8)), 'Perm.W|X')
+ self.assertEqual(str(Perm(~0)), 'Perm.R|W|X')
+ self.assertEqual(str(Perm(~8)), 'Perm.R|W|X')
Open = self.Open
self.assertEqual(str(Open.RO), 'Open.RO')
@@ -1991,12 +2040,12 @@
self.assertEqual(str(Open.RO | Open.CE), 'Open.CE')
self.assertEqual(str(Open.WO | Open.CE), 'Open.CE|WO')
self.assertEqual(str(Open(4)), 'Open.4')
- self.assertEqual(str(~Open.RO), 'Open.CE|AC|-524292')
- self.assertEqual(str(~Open.WO), 'Open.CE|RW|-524292')
- self.assertEqual(str(~Open.AC), 'Open.CE|-524292')
- self.assertEqual(str(~(Open.RO | Open.CE)), 'Open.AC|-524292')
- self.assertEqual(str(~(Open.WO | Open.CE)), 'Open.RW|-524292')
- self.assertEqual(str(Open(~4)), 'Open.CE|AC|-524296')
+ self.assertEqual(str(~Open.RO), 'Open.CE|AC|RW|WO')
+ self.assertEqual(str(~Open.WO), 'Open.CE|RW')
+ self.assertEqual(str(~Open.AC), 'Open.CE')
+ self.assertEqual(str(~(Open.RO | Open.CE)), 'Open.AC|RW|WO')
+ self.assertEqual(str(~(Open.WO | Open.CE)), 'Open.RW')
+ self.assertEqual(str(Open(~4)), 'Open.CE|AC|RW|WO')
def test_repr(self):
Perm = self.Perm
@@ -2008,14 +2057,14 @@
self.assertEqual(repr(Perm.R | 8), '<Perm.8|R: 12>')
self.assertEqual(repr(Perm(0)), '<Perm.0: 0>')
self.assertEqual(repr(Perm(8)), '<Perm.8: 8>')
- self.assertEqual(repr(~Perm.R), '<Perm.W|X|-8: -5>')
- self.assertEqual(repr(~Perm.W), '<Perm.R|X|-8: -3>')
- self.assertEqual(repr(~Perm.X), '<Perm.R|W|-8: -2>')
- self.assertEqual(repr(~(Perm.R | Perm.W)), '<Perm.X|-8: -7>')
+ self.assertEqual(repr(~Perm.R), '<Perm.W|X: -5>')
+ self.assertEqual(repr(~Perm.W), '<Perm.R|X: -3>')
+ self.assertEqual(repr(~Perm.X), '<Perm.R|W: -2>')
+ self.assertEqual(repr(~(Perm.R | Perm.W)), '<Perm.X: -7>')
self.assertEqual(repr(~(Perm.R | Perm.W | Perm.X)), '<Perm.-8: -8>')
- self.assertEqual(repr(~(Perm.R | 8)), '<Perm.W|X|-16: -13>')
- self.assertEqual(repr(Perm(~0)), '<Perm.R|W|X|-8: -1>')
- self.assertEqual(repr(Perm(~8)), '<Perm.R|W|X|-16: -9>')
+ self.assertEqual(repr(~(Perm.R | 8)), '<Perm.W|X: -13>')
+ self.assertEqual(repr(Perm(~0)), '<Perm.R|W|X: -1>')
+ self.assertEqual(repr(Perm(~8)), '<Perm.R|W|X: -9>')
Open = self.Open
self.assertEqual(repr(Open.RO), '<Open.RO: 0>')
@@ -2024,12 +2073,12 @@
self.assertEqual(repr(Open.RO | Open.CE), '<Open.CE: 524288>')
self.assertEqual(repr(Open.WO | Open.CE), '<Open.CE|WO: 524289>')
self.assertEqual(repr(Open(4)), '<Open.4: 4>')
- self.assertEqual(repr(~Open.RO), '<Open.CE|AC|-524292: -1>')
- self.assertEqual(repr(~Open.WO), '<Open.CE|RW|-524292: -2>')
- self.assertEqual(repr(~Open.AC), '<Open.CE|-524292: -4>')
- self.assertEqual(repr(~(Open.RO | Open.CE)), '<Open.AC|-524292: -524289>')
- self.assertEqual(repr(~(Open.WO | Open.CE)), '<Open.RW|-524292: -524290>')
- self.assertEqual(repr(Open(~4)), '<Open.CE|AC|-524296: -5>')
+ self.assertEqual(repr(~Open.RO), '<Open.CE|AC|RW|WO: -1>')
+ self.assertEqual(repr(~Open.WO), '<Open.CE|RW: -2>')
+ self.assertEqual(repr(~Open.AC), '<Open.CE: -4>')
+ self.assertEqual(repr(~(Open.RO | Open.CE)), '<Open.AC|RW|WO: -524289>')
+ self.assertEqual(repr(~(Open.WO | Open.CE)), '<Open.RW: -524290>')
+ self.assertEqual(repr(Open(~4)), '<Open.CE|AC|RW|WO: -5>')
def test_or(self):
Perm = self.Perm
--
Repository URL: https://hg.python.org/cpython
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