Used "is" for comparisons with None.

django/core/mail/message.py

@@ -292,7 +292,8 @@ def attach(self, filename=None, content=None, mimetype=None):
         into the resulting message attachments.
         """
         if isinstance(filename, MIMEBase):
-            assert content == mimetype == None
+            assert content is None
+            assert mimetype is None
             self.attachments.append(filename)
         else:
             assert content is not None

django/forms/widgets.py

@@ -508,7 +508,7 @@ def render(self, name, value, attrs=None, choices=()):
         return mark_safe('\n'.join(output))
 
     def render_option(self, selected_choices, option_value, option_label):
-        if option_value == None:
+        if option_value is None:
             option_value = ''
         option_value = force_text(option_value)
         if option_value in selected_choices:

django/middleware/cache.py

@@ -96,7 +96,7 @@ def process_response(self, request, response):
         # Control" header before reverting to using the default cache_timeout
         # length.
         timeout = get_max_age(response)
-        if timeout == None:
+        if timeout is None:
             timeout = self.cache_timeout
         elif timeout == 0:
             # max-age was set to 0, don't bother caching.

django/template/defaulttags.py

@@ -315,7 +315,7 @@ def resolve_expression(self, obj, context):
 
     def render(self, context):
         obj_list = self.target.resolve(context, True)
-        if obj_list == None:
+        if obj_list is None:
             # target variable wasn't found in context; fail silently.
             context[self.var_name] = []
             return ''

django/test/_doctest.py

@@ -1345,7 +1345,7 @@ def py3_displayhook(value):
                     # exception message will be in group(2)
                     m = re.match(r'(.*)\.(\w+:.+\s)', exc_msg)
                     # make sure there's a match
-                    if m != None:
+                    if m is not None:
                         f_name = m.group(1)
                         # check to see if m.group(1) contains the module name
                         if f_name == exception[0].__module__:

tests/basic/tests.py

@@ -33,7 +33,7 @@ def test_lookup(self):
         a.save()
 
         # Now it has an ID.
-        self.assertTrue(a.id != None)
+        self.assertTrue(a.id is not None)
 
         # Models have a pk property that is an alias for the primary key
         # attribute (by default, the 'id' attribute).
@@ -585,7 +585,7 @@ def test_field_ordering(self):
         f3 = Field()
         self.assertTrue(f2 < f1)
         self.assertTrue(f3 > f1)
-        self.assertFalse(f1 == None)
+        self.assertFalse(f1 is None)
         self.assertFalse(f2 in (None, 1, ''))
 
     def test_extra_method_select_argument_with_dashes_and_values(self):

tests/comment_tests/tests/test_comment_view.py

@@ -243,29 +243,29 @@ def testCommentNext(self):
         response = self.client.post("/post/", data)
         location = response["Location"]
         match = post_redirect_re.match(location)
-        self.assertTrue(match != None, "Unexpected redirect location: %s" % location)
+        self.assertTrue(match is not None, "Unexpected redirect location: %s" % location)
 
         data["next"] = "/somewhere/else/"
         data["comment"] = "This is another comment"
         response = self.client.post("/post/", data)
         location = response["Location"]
         match = re.search(r"^http://testserver/somewhere/else/\?c=\d+$", location)
-        self.assertTrue(match != None, "Unexpected redirect location: %s" % location)
+        self.assertTrue(match is not None, "Unexpected redirect location: %s" % location)
 
         data["next"] = "http://badserver/somewhere/else/"
         data["comment"] = "This is another comment with an unsafe next url"
         response = self.client.post("/post/", data)
         location = response["Location"]
         match = post_redirect_re.match(location)
-        self.assertTrue(match != None, "Unsafe redirection to: %s" % location)
+        self.assertTrue(match is not None, "Unsafe redirection to: %s" % location)
 
     def testCommentDoneView(self):
         a = Article.objects.get(pk=1)
         data = self.getValidData(a)
         response = self.client.post("/post/", data)
         location = response["Location"]
         match = post_redirect_re.match(location)
-        self.assertTrue(match != None, "Unexpected redirect location: %s" % location)
+        self.assertTrue(match is not None, "Unexpected redirect location: %s" % location)
         pk = int(match.group('pk'))
         response = self.client.get(location)
         self.assertTemplateUsed(response, "comments/posted.html")
@@ -282,7 +282,7 @@ def testCommentNextWithQueryString(self):
         response = self.client.post("/post/", data)
         location = response["Location"]
         match = re.search(r"^http://testserver/somewhere/else/\?foo=bar&c=\d+$", location)
-        self.assertTrue(match != None, "Unexpected redirect location: %s" % location)
+        self.assertTrue(match is not None, "Unexpected redirect location: %s" % location)
 
     def testCommentPostRedirectWithInvalidIntegerPK(self):
         """
@@ -311,7 +311,7 @@ def testCommentNextWithQueryStringAndAnchor(self):
         response = self.client.post("/post/", data)
         location = response["Location"]
         match = re.search(r"^http://testserver/somewhere/else/\?foo=bar&c=\d+#baz$", location)
-        self.assertTrue(match != None, "Unexpected redirect location: %s" % location)
+        self.assertTrue(match is not None, "Unexpected redirect location: %s" % location)
 
         # Without a query string
         a = Article.objects.get(pk=1)
@@ -321,4 +321,4 @@ def testCommentNextWithQueryStringAndAnchor(self):
         response = self.client.post("/post/", data)
         location = response["Location"]
         match = re.search(r"^http://testserver/somewhere/else/\?c=\d+#baz$", location)
-        self.assertTrue(match != None, "Unexpected redirect location: %s" % location)
+        self.assertTrue(match is not None, "Unexpected redirect location: %s" % location)

tests/signals_regress/tests.py

@@ -34,11 +34,11 @@ def post_save_test(self, signal, sender, instance, **kwargs):
 
     def pre_delete_test(self, signal, sender, instance, **kwargs):
         self.signal_output.append('pre_save signal, %s' % instance)
-        self.signal_output.append('instance.id is not None: %s' % (instance.id != None))
+        self.signal_output.append('instance.id is not None: %s' % (instance.id is not None))
 
     def post_delete_test(self, signal, sender, instance, **kwargs):
         self.signal_output.append('post_delete signal, %s' % instance)
-        self.signal_output.append('instance.id is not None: %s' % (instance.id != None))
+        self.signal_output.append('instance.id is not None: %s' % (instance.id is not None))
 
     def setUp(self):
         self.signal_output = []