Add __ne__ built-in function

In Python 3 __ne__ by default delegates to __eq__ and inverts the
result, but in Python 2 they urge you to define __ne__ when you
define __eq__ for it to work properly [1].There are no implied
relationships among the comparison operators. The truth of x==y
does not imply that x!=y is false. Accordingly, when defining
__eq__(), one should also define __ne__() so that the operators
will behave as expected.
[1]https://docs.python.org/2/reference/datamodel.html#object.__ne__

Change-Id: I7d41128d88c79ebb5de1c38f8aaf98cc9561367c

glance/domain/__init__.py

@@ -295,6 +295,9 @@ class ExtraProperties(collections.MutableMapping, dict):
         else:
             return False
 
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
     def __len__(self):
         return dict(self).__len__()
 

glance/location.py

@@ -303,6 +303,9 @@ class StoreLocations(collections.MutableSequence):
     def __eq__(self, other):
         return self.value == self.__cast(other)
 
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
     def __iter__(self):
         return iter(self.value)
 

glance/quota/__init__.py

@@ -150,6 +150,9 @@ class QuotaImageTagsProxy(object):
     def __eq__(self, other):
         return self.tags == other
 
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
     def __iter__(self, *args, **kwargs):
         return self.tags.__iter__(*args, **kwargs)
 
@@ -214,6 +217,9 @@ class QuotaImageLocationsProxy(object):
     def __eq__(self, other):
         return self.locations == other
 
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
     def __getitem__(self, *args, **kwargs):
         return self.locations.__getitem__(*args, **kwargs)
 

glance/tests/unit/test_domain.py

@@ -298,7 +298,7 @@ class TestExtraProperties(test_utils.BaseTestCase):
         a_dict = {'foo': 'bar', 'snitch': 'golden'}
         extra_properties = domain.ExtraProperties(a_dict)
         ref_extra_properties = {'boo': 'far', 'gnitch': 'solden'}
-        self.assertFalse(extra_properties.__eq__(ref_extra_properties))
+        self.assertNotEqual(ref_extra_properties, extra_properties)
 
     def test_eq_with_unequal_ExtraProperties_object(self):
         a_dict = {'foo': 'bar', 'snitch': 'golden'}
@@ -306,13 +306,13 @@ class TestExtraProperties(test_utils.BaseTestCase):
         ref_extra_properties = domain.ExtraProperties()
         ref_extra_properties['gnitch'] = 'solden'
         ref_extra_properties['boo'] = 'far'
-        self.assertFalse(extra_properties.__eq__(ref_extra_properties))
+        self.assertNotEqual(ref_extra_properties, extra_properties)
 
     def test_eq_with_incompatible_object(self):
         a_dict = {'foo': 'bar', 'snitch': 'golden'}
         extra_properties = domain.ExtraProperties(a_dict)
         random_list = ['foo', 'bar']
-        self.assertFalse(extra_properties.__eq__(random_list))
+        self.assertNotEqual(random_list, extra_properties)
 
 
 class TestTaskFactory(test_utils.BaseTestCase):

glance/tests/unit/test_quota.py

@@ -572,6 +572,10 @@ class TestQuotaImageTagsProxy(test_utils.BaseTestCase):
         proxy = glance.quota.QuotaImageTagsProxy(set([]))
         self.assertEqual(set([]), proxy)
 
+    def test_not_equals(self):
+        proxy = glance.quota.QuotaImageTagsProxy(set([]))
+        self.assertNotEqual('foo', proxy)
+
     def test_contains(self):
         proxy = glance.quota.QuotaImageTagsProxy(set(['foo']))
         self.assertIn('foo', proxy)