diff --git a/rest_framework/decorators.py b/rest_framework/decorators.py
index 3b572c09e..619481756 100644
--- a/rest_framework/decorators.py
+++ b/rest_framework/decorators.py
@@ -36,7 +36,7 @@ def api_view(http_method_names=None):
         #     WrappedAPIView.__doc__ = func.doc    <--- Not possible to do this
 
         # api_view applied without (method_names)
-        assert not(isinstance(http_method_names, types.FunctionType)), \
+        assert not (isinstance(http_method_names, types.FunctionType)), \
             '@api_view missing list of allowed HTTP methods'
 
         # api_view applied with eg. string instead of list of strings
diff --git a/tests/test_throttling.py b/tests/test_throttling.py
index d5a61232d..be9decebc 100644
--- a/tests/test_throttling.py
+++ b/tests/test_throttling.py
@@ -192,7 +192,7 @@ class ThrottlingTests(TestCase):
             if expect is not None:
                 assert response['Retry-After'] == expect
             else:
-                assert not'Retry-After' in response
+                assert 'Retry-After' not in response
 
     def test_seconds_fields(self):
         """