[Python-checkins] [3.7] bpo-33217: deprecate non-Enum lookups in Enums (GH-6392)
Ethan Furman
webhook-mailer at python.org
Wed Apr 11 21:56:29 EDT 2018
https://github.com/python/cpython/commit/3715176557cf87925c8f89b98939c7daf9bf48e2
commit: 3715176557cf87925c8f89b98939c7daf9bf48e2
branch: 3.7
author: Ethan Furman <ethan at stoneleaf.us>
committer: GitHub <noreply at github.com>
date: 2018-04-11T18:56:25-07:00
summary:
[3.7] bpo-33217: deprecate non-Enum lookups in Enums (GH-6392)
deprecate non-Enum lookups in Enums
Lookups such as `1 in Color` and `2 in SomeFlag()` will raise TypeError
in 3.8+.
files:
A Misc/NEWS.d/next/Library/2018-04-05-13-36-09.bpo-33217.FfOKDI.rst
M Doc/library/enum.rst
M Doc/whatsnew/3.7.rst
M Lib/enum.py
M Lib/test/test_enum.py
diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst
index fc65a3d078f1..787670c6ddad 100644
--- a/Doc/library/enum.rst
+++ b/Doc/library/enum.rst
@@ -976,7 +976,7 @@ Enum Classes
The :class:`EnumMeta` metaclass is responsible for providing the
:meth:`__contains__`, :meth:`__dir__`, :meth:`__iter__` and other methods that
allow one to do things with an :class:`Enum` class that fail on a typical
-class, such as `list(Color)` or `some_var in Color`. :class:`EnumMeta` is
+class, such as `list(Color)` or `some_enum_var in Color`. :class:`EnumMeta` is
responsible for ensuring that various other methods on the final :class:`Enum`
class are correct (such as :meth:`__new__`, :meth:`__getnewargs__`,
:meth:`__str__` and :meth:`__repr__`).
diff --git a/Doc/whatsnew/3.7.rst b/Doc/whatsnew/3.7.rst
index 08c7b12574c6..3a170c07ab4f 100644
--- a/Doc/whatsnew/3.7.rst
+++ b/Doc/whatsnew/3.7.rst
@@ -1041,6 +1041,12 @@ Deprecated
:meth:`ssl.SSLContext.wrap_socket` instead.
(Contributed by Christian Heimes in :issue:`28124`.)
+- In Python 3.8, attempting to check for non-Enum objects in :class:`Enum`
+ classes will raise a :exc:`TypeError` (e.g. ``1 in Color``); similarly,
+ attempting to check for non-Flag objects in a :class:`Flag` member will
+ raise :exc:`TypeError` (e.g. ``1 in Perm.RW``); currently, both operations
+ return :const:`False` instead.
+
Windows Only
------------
diff --git a/Lib/enum.py b/Lib/enum.py
index e5fe6f3b94a1..8c8409bd4efd 100644
--- a/Lib/enum.py
+++ b/Lib/enum.py
@@ -309,6 +309,12 @@ def __call__(cls, value, names=None, *, module=None, qualname=None, type=None, s
return cls._create_(value, names, module=module, qualname=qualname, type=type, start=start)
def __contains__(cls, member):
+ if not isinstance(member, Enum):
+ import warnings
+ warnings.warn(
+ "using non-Enums in containment checks will raise "
+ "TypeError in Python 3.8",
+ DeprecationWarning, 2)
return isinstance(member, cls) and member._name_ in cls._member_map_
def __delattr__(cls, attr):
@@ -713,7 +719,12 @@ def _create_pseudo_member_(cls, value):
def __contains__(self, other):
if not isinstance(other, self.__class__):
- return NotImplemented
+ import warnings
+ warnings.warn(
+ "using non-Flags in containment checks will raise "
+ "TypeError in Python 3.8",
+ DeprecationWarning, 2)
+ return False
return other._value_ & self._value_ == other._value_
def __repr__(self):
diff --git a/Lib/test/test_enum.py b/Lib/test/test_enum.py
index 97559712b1dc..ef2d1daaf942 100644
--- a/Lib/test/test_enum.py
+++ b/Lib/test/test_enum.py
@@ -325,7 +325,10 @@ class IntLogic(int, Enum):
def test_contains(self):
Season = self.Season
self.assertIn(Season.AUTUMN, Season)
- self.assertNotIn(3, Season)
+ with self.assertWarns(DeprecationWarning):
+ self.assertNotIn(3, Season)
+ with self.assertWarns(DeprecationWarning):
+ self.assertNotIn('AUTUMN', Season)
val = Season(3)
self.assertIn(val, Season)
@@ -334,6 +337,11 @@ class OtherEnum(Enum):
one = 1; two = 2
self.assertNotIn(OtherEnum.two, Season)
+ def test_member_contains(self):
+ self.assertRaises(TypeError, lambda: 'test' in self.Season.AUTUMN)
+ self.assertRaises(TypeError, lambda: 3 in self.Season.AUTUMN)
+ self.assertRaises(TypeError, lambda: 'AUTUMN' in self.Season.AUTUMN)
+
def test_comparisons(self):
Season = self.Season
with self.assertRaises(TypeError):
@@ -1745,6 +1753,13 @@ class TestFlag(unittest.TestCase):
class Perm(Flag):
R, W, X = 4, 2, 1
+ class Color(Flag):
+ BLACK = 0
+ RED = 1
+ GREEN = 2
+ BLUE = 4
+ PURPLE = RED|BLUE
+
class Open(Flag):
RO = 0
WO = 1
@@ -1954,7 +1969,21 @@ def test_pickle(self):
test_pickle_dump_load(self.assertIs, FlagStooges.CURLY|FlagStooges.MOE)
test_pickle_dump_load(self.assertIs, FlagStooges)
- def test_containment(self):
+ def test_contains(self):
+ Open = self.Open
+ Color = self.Color
+ self.assertFalse(Color.BLACK in Open)
+ self.assertFalse(Open.RO in Color)
+ with self.assertWarns(DeprecationWarning):
+ self.assertFalse('BLACK' in Color)
+ with self.assertWarns(DeprecationWarning):
+ self.assertFalse('RO' in Open)
+ with self.assertWarns(DeprecationWarning):
+ self.assertFalse(1 in Color)
+ with self.assertWarns(DeprecationWarning):
+ self.assertFalse(1 in Open)
+
+ def test_member_contains(self):
Perm = self.Perm
R, W, X = Perm
RW = R | W
@@ -2065,6 +2094,13 @@ class Perm(IntFlag):
W = 1 << 1
R = 1 << 2
+ class Color(IntFlag):
+ BLACK = 0
+ RED = 1
+ GREEN = 2
+ BLUE = 4
+ PURPLE = RED|BLUE
+
class Open(IntFlag):
RO = 0
WO = 1
@@ -2340,7 +2376,23 @@ def test_programatic_function_from_empty_tuple(self):
self.assertEqual(len(lst), len(Thing))
self.assertEqual(len(Thing), 0, Thing)
- def test_containment(self):
+ def test_contains(self):
+ Color = self.Color
+ Open = self.Open
+ self.assertTrue(Color.GREEN in Color)
+ self.assertTrue(Open.RW in Open)
+ self.assertFalse(Color.GREEN in Open)
+ self.assertFalse(Open.RW in Color)
+ with self.assertWarns(DeprecationWarning):
+ self.assertFalse('GREEN' in Color)
+ with self.assertWarns(DeprecationWarning):
+ self.assertFalse('RW' in Open)
+ with self.assertWarns(DeprecationWarning):
+ self.assertFalse(2 in Color)
+ with self.assertWarns(DeprecationWarning):
+ self.assertFalse(2 in Open)
+
+ def test_member_contains(self):
Perm = self.Perm
R, W, X = Perm
RW = R | W
@@ -2359,6 +2411,8 @@ def test_containment(self):
self.assertFalse(R in WX)
self.assertFalse(W in RX)
self.assertFalse(X in RW)
+ with self.assertWarns(DeprecationWarning):
+ self.assertFalse('swallow' in RW)
def test_bool(self):
Perm = self.Perm
diff --git a/Misc/NEWS.d/next/Library/2018-04-05-13-36-09.bpo-33217.FfOKDI.rst b/Misc/NEWS.d/next/Library/2018-04-05-13-36-09.bpo-33217.FfOKDI.rst
new file mode 100644
index 000000000000..8dfc9e5a15c0
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-04-05-13-36-09.bpo-33217.FfOKDI.rst
@@ -0,0 +1,2 @@
+Deprecate looking up non-Enum objects in Enum classes and Enum members (will
+raise :exc:`TypeError` in 3.8+).
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