[Python-checkins] cpython (3.4): Issue #21408: The default __ne__() now returns NotImplemented if __eq__()
serhiy.storchaka
python-checkins at python.org
Mon Jan 26 09:05:16 CET 2015
https://hg.python.org/cpython/rev/e516badfd3b2
changeset: 94286:e516badfd3b2
branch: 3.4
parent: 94282:25ecf3d0ea03
user: Serhiy Storchaka <storchaka at gmail.com>
date: Mon Jan 26 09:57:07 2015 +0200
summary:
Issue #21408: The default __ne__() now returns NotImplemented if __eq__()
returned NotImplemented. Removed incorrect implementations of __ne__().
files:
Lib/_collections_abc.py | 6 --
Lib/doctest.py | 9 ---
Lib/lib2to3/pytree.py | 10 ----
Lib/numbers.py | 5 --
Lib/pathlib.py | 3 -
Lib/test/test_binop.py | 4 -
Lib/test/test_compare.py | 65 +++++++++++++++++++++++++++-
Lib/unittest/case.py | 3 -
Lib/unittest/suite.py | 3 -
Misc/NEWS | 7 +++
Objects/typeobject.c | 9 +++-
11 files changed, 77 insertions(+), 47 deletions(-)
diff --git a/Lib/_collections_abc.py b/Lib/_collections_abc.py
--- a/Lib/_collections_abc.py
+++ b/Lib/_collections_abc.py
@@ -224,9 +224,6 @@
return NotImplemented
return len(self) == len(other) and self.__le__(other)
- def __ne__(self, other):
- return not (self == other)
-
@classmethod
def _from_iterable(cls, it):
'''Construct an instance of the class from any iterable input.
@@ -451,9 +448,6 @@
return NotImplemented
return dict(self.items()) == dict(other.items())
- def __ne__(self, other):
- return not (self == other)
-
Mapping.register(mappingproxy)
diff --git a/Lib/doctest.py b/Lib/doctest.py
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -481,9 +481,6 @@
self.options == other.options and \
self.exc_msg == other.exc_msg
- def __ne__(self, other):
- return not self == other
-
def __hash__(self):
return hash((self.source, self.want, self.lineno, self.indent,
self.exc_msg))
@@ -547,9 +544,6 @@
self.filename == other.filename and \
self.lineno == other.lineno
- def __ne__(self, other):
- return not self == other
-
def __hash__(self):
return hash((self.docstring, self.name, self.filename, self.lineno))
@@ -2289,9 +2283,6 @@
self._dt_tearDown == other._dt_tearDown and \
self._dt_checker == other._dt_checker
- def __ne__(self, other):
- return not self == other
-
def __hash__(self):
return hash((self._dt_optionflags, self._dt_setUp, self._dt_tearDown,
self._dt_checker))
diff --git a/Lib/lib2to3/pytree.py b/Lib/lib2to3/pytree.py
--- a/Lib/lib2to3/pytree.py
+++ b/Lib/lib2to3/pytree.py
@@ -64,16 +64,6 @@
__hash__ = None # For Py3 compatibility.
- def __ne__(self, other):
- """
- Compare two nodes for inequality.
-
- This calls the method _eq().
- """
- if self.__class__ is not other.__class__:
- return NotImplemented
- return not self._eq(other)
-
def _eq(self, other):
"""
Compare two nodes for equality.
diff --git a/Lib/numbers.py b/Lib/numbers.py
--- a/Lib/numbers.py
+++ b/Lib/numbers.py
@@ -141,11 +141,6 @@
"""self == other"""
raise NotImplementedError
- def __ne__(self, other):
- """self != other"""
- # The default __ne__ doesn't negate __eq__ until 3.0.
- return not (self == other)
-
Complex.register(complex)
diff --git a/Lib/pathlib.py b/Lib/pathlib.py
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -665,9 +665,6 @@
return NotImplemented
return self._cparts == other._cparts and self._flavour is other._flavour
- def __ne__(self, other):
- return not self == other
-
def __hash__(self):
try:
return self._hash
diff --git a/Lib/test/test_binop.py b/Lib/test/test_binop.py
--- a/Lib/test/test_binop.py
+++ b/Lib/test/test_binop.py
@@ -194,10 +194,6 @@
return float(self) == other
return NotImplemented
- def __ne__(self, other):
- """Compare two Rats for inequality."""
- return not self == other
-
class RatTestCase(unittest.TestCase):
"""Unit tests for Rat class and its support utilities."""
diff --git a/Lib/test/test_compare.py b/Lib/test/test_compare.py
--- a/Lib/test/test_compare.py
+++ b/Lib/test/test_compare.py
@@ -48,8 +48,69 @@
def test_ne_defaults_to_not_eq(self):
a = Cmp(1)
b = Cmp(1)
- self.assertTrue(a == b)
- self.assertFalse(a != b)
+ c = Cmp(2)
+ self.assertIs(a == b, True)
+ self.assertIs(a != b, False)
+ self.assertIs(a != c, True)
+
+ def test_ne_high_priority(self):
+ """object.__ne__() should allow reflected __ne__() to be tried"""
+ calls = []
+ class Left:
+ # Inherits object.__ne__()
+ def __eq__(*args):
+ calls.append('Left.__eq__')
+ return NotImplemented
+ class Right:
+ def __eq__(*args):
+ calls.append('Right.__eq__')
+ return NotImplemented
+ def __ne__(*args):
+ calls.append('Right.__ne__')
+ return NotImplemented
+ Left() != Right()
+ self.assertSequenceEqual(calls, ['Left.__eq__', 'Right.__ne__'])
+
+ def test_ne_low_priority(self):
+ """object.__ne__() should not invoke reflected __eq__()"""
+ calls = []
+ class Base:
+ # Inherits object.__ne__()
+ def __eq__(*args):
+ calls.append('Base.__eq__')
+ return NotImplemented
+ class Derived(Base): # Subclassing forces higher priority
+ def __eq__(*args):
+ calls.append('Derived.__eq__')
+ return NotImplemented
+ def __ne__(*args):
+ calls.append('Derived.__ne__')
+ return NotImplemented
+ Base() != Derived()
+ self.assertSequenceEqual(calls, ['Derived.__ne__', 'Base.__eq__'])
+
+ def test_other_delegation(self):
+ """No default delegation between operations except __ne__()"""
+ ops = (
+ ('__eq__', lambda a, b: a == b),
+ ('__lt__', lambda a, b: a < b),
+ ('__le__', lambda a, b: a <= b),
+ ('__gt__', lambda a, b: a > b),
+ ('__ge__', lambda a, b: a >= b),
+ )
+ for name, func in ops:
+ with self.subTest(name):
+ def unexpected(*args):
+ self.fail('Unexpected operator method called')
+ class C:
+ __ne__ = unexpected
+ for other, _ in ops:
+ if other != name:
+ setattr(C, other, unexpected)
+ if name == '__eq__':
+ self.assertIs(func(C(), object()), False)
+ else:
+ self.assertRaises(TypeError, func, C(), object())
def test_issue_1393(self):
x = lambda: None
diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -1342,9 +1342,6 @@
self._testFunc == other._testFunc and \
self._description == other._description
- def __ne__(self, other):
- return not self == other
-
def __hash__(self):
return hash((type(self), self._setUpFunc, self._tearDownFunc,
self._testFunc, self._description))
diff --git a/Lib/unittest/suite.py b/Lib/unittest/suite.py
--- a/Lib/unittest/suite.py
+++ b/Lib/unittest/suite.py
@@ -31,9 +31,6 @@
return NotImplemented
return list(self) == list(other)
- def __ne__(self, other):
- return not self == other
-
def __iter__(self):
return iter(self._tests)
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -11,6 +11,9 @@
Core and Builtins
-----------------
+- Issue #21408: The default __ne__() now returns NotImplemented if __eq__()
+ returned NotImplemented.
+
- Issue #23321: Fixed a crash in str.decode() when error handler returned
replacment string longer than mailformed input data.
@@ -47,6 +50,10 @@
Library
-------
+- Issue #21408: Removed incorrect implementations of __ne__() which didn't
+ returned NotImplemented if __eq__() returned NotImplemented. The default
+ __ne__() now works correctly.
+
- Issue #19996: :class:`email.feedparser.FeedParser` now handles (malformed)
headers with no key rather than amusing the body has started.
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -3348,9 +3348,14 @@
break;
case Py_NE:
- /* By default, != returns the opposite of ==,
+ /* By default, __ne__() delegates to __eq__() and inverts the result,
unless the latter returns NotImplemented. */
- res = PyObject_RichCompare(self, other, Py_EQ);
+ if (self->ob_type->tp_richcompare == NULL) {
+ res = Py_NotImplemented;
+ Py_INCREF(res);
+ break;
+ }
+ res = (*self->ob_type->tp_richcompare)(self, other, Py_EQ);
if (res != NULL && res != Py_NotImplemented) {
int ok = PyObject_IsTrue(res);
Py_DECREF(res);
--
Repository URL: https://hg.python.org/cpython
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