diff --git a/horizon/test/tests/middleware.py b/horizon/test/tests/middleware.py
index b9a067ed55..c586fa0da0 100644
--- a/horizon/test/tests/middleware.py
+++ b/horizon/test/tests/middleware.py
@@ -131,14 +131,14 @@ class OperationLogMiddlewareTest(test.TestCase):
         self.assertEqual(302, resp.status_code)
         log_args = mock_logger.info.call_args[0]
         logging_str = log_args[0] % log_args[1]
-        self.assertTrue(request.user.username in logging_str)
-        self.assertTrue(self.http_referer in logging_str)
-        self.assertTrue(settings.LOGIN_URL in logging_str)
-        self.assertTrue('POST' in logging_str)
-        self.assertTrue('302' in logging_str)
+        self.assertIn(request.user.username, logging_str)
+        self.assertIn(self.http_referer, logging_str)
+        self.assertIn(settings.LOGIN_URL, logging_str)
+        self.assertIn('POST', logging_str)
+        self.assertIn('302', logging_str)
         post_data = ['"username": "admin"', '"password": "********"']
         for data in post_data:
-            self.assertTrue(data in logging_str)
+            self.assertIn(data, logging_str)
 
     @override_settings(OPERATION_LOG_ENABLED=True)
     @override_settings(OPERATION_LOG_OPTIONS={'target_methods': ['GET']})
@@ -154,11 +154,11 @@ class OperationLogMiddlewareTest(test.TestCase):
         self.assertEqual(302, resp.status_code)
         log_args = mock_logger.info.call_args[0]
         logging_str = log_args[0] % log_args[1]
-        self.assertTrue(request.user.username in logging_str)
-        self.assertTrue(self.http_referer in logging_str)
-        self.assertTrue(request.path in logging_str)
-        self.assertTrue('GET' in logging_str)
-        self.assertTrue('302' in logging_str)
+        self.assertIn(request.user.username, logging_str)
+        self.assertIn(self.http_referer, logging_str)
+        self.assertIn(request.path, logging_str)
+        self.assertIn('GET', logging_str)
+        self.assertIn('302', logging_str)
 
     @override_settings(OPERATION_LOG_ENABLED=True)
     @patch(('horizon.middleware.operation_log.OperationLogMiddleware.'
@@ -186,10 +186,10 @@ class OperationLogMiddlewareTest(test.TestCase):
         log_args = mock_logger.info.call_args[0]
         logging_str = log_args[0] % log_args[1]
         self.assertTrue(mock_logger.info.called)
-        self.assertTrue(request.user.username in logging_str)
-        self.assertTrue(self.http_referer in logging_str)
-        self.assertTrue(settings.LOGIN_URL in logging_str)
-        self.assertTrue('Unexpected error occurred.' in logging_str)
+        self.assertIn(request.user.username, logging_str)
+        self.assertIn(self.http_referer, logging_str)
+        self.assertIn(settings.LOGIN_URL, logging_str)
+        self.assertIn('Unexpected error occurred.', logging_str)
         post_data = ['"username": "admin"', '"password": "********"']
         for data in post_data:
             self.assertTrue(data in logging_str)
diff --git a/openstack_dashboard/dashboards/project/access_and_security/tests.py b/openstack_dashboard/dashboards/project/access_and_security/tests.py
index de1a066e98..2e0af777fc 100644
--- a/openstack_dashboard/dashboards/project/access_and_security/tests.py
+++ b/openstack_dashboard/dashboards/project/access_and_security/tests.py
@@ -287,8 +287,8 @@ class SecurityGroupTabTests(test.TestCase):
 
         create_action = self.getAndAssertTableAction(res, 'security_groups',
                                                      'create')
-        self.assertTrue('disabled' in create_action.classes,
-                        'The create button should be disabled')
+        self.assertIn('disabled', create_action.classes,
+                      'The create button should be disabled')
 
     def test_create_button_disabled_when_quota_exceeded_neutron_disabled(self):
         self._test_create_button_disabled_when_quota_exceeded(False)
diff --git a/openstack_dashboard/dashboards/project/networks/tests.py b/openstack_dashboard/dashboards/project/networks/tests.py
index 5c83ff834c..d74b2d6af2 100644
--- a/openstack_dashboard/dashboards/project/networks/tests.py
+++ b/openstack_dashboard/dashboards/project/networks/tests.py
@@ -1244,8 +1244,8 @@ class NetworkViewTests(test.TestCase, NetworkStubMixin):
         self.assertItemsEqual(networks, self.networks.list())
 
         button = find_button_fn(res)
-        self.assertTrue('disabled' in button.classes,
-                        "The create button should be disabled")
+        self.assertIn('disabled', button.classes,
+                      "The create button should be disabled")
         return button
 
     @test.create_stubs({api.neutron: ('network_list',),
@@ -1327,8 +1327,8 @@ class NetworkViewTests(test.TestCase, NetworkStubMixin):
         self.assertItemsEqual(subnets, self.subnets.list())
 
         create_action = self.getAndAssertTableAction(res, 'subnets', 'create')
-        self.assertTrue('disabled' in create_action.classes,
-                        'The create button should be disabled')
+        self.assertIn('disabled', create_action.classes,
+                      'The create button should be disabled')
 
     @test.create_stubs({api.neutron: ('network_list',),
                         quotas: ('tenant_quota_usages',)})
diff --git a/openstack_dashboard/dashboards/project/routers/tests.py b/openstack_dashboard/dashboards/project/routers/tests.py
index 36022038c0..975cc7f262 100644
--- a/openstack_dashboard/dashboards/project/routers/tests.py
+++ b/openstack_dashboard/dashboards/project/routers/tests.py
@@ -807,8 +807,8 @@ class RouterViewTests(RouterMixin, test.TestCase):
         self.assertItemsEqual(routers, self.routers.list())
 
         create_action = self.getAndAssertTableAction(res, 'routers', 'create')
-        self.assertTrue('disabled' in create_action.classes,
-                        'Create button is not disabled')
+        self.assertIn('disabled', create_action.classes,
+                      'Create button is not disabled')
         self.assertEqual('Create Router (Quota exceeded)',
                          create_action.verbose_name)
 
diff --git a/openstack_dashboard/dashboards/project/volumes/volumes/tests.py b/openstack_dashboard/dashboards/project/volumes/volumes/tests.py
index 778e88ba07..66c59ab1ba 100644
--- a/openstack_dashboard/dashboards/project/volumes/volumes/tests.py
+++ b/openstack_dashboard/dashboards/project/volumes/volumes/tests.py
@@ -1148,8 +1148,8 @@ class VolumeViewTests(test.TestCase):
 
         snapshot_action = self._get_volume_row_action_from_ajax(
             res, 'snapshots', volume.id)
-        self.assertTrue('disabled' in snapshot_action.classes,
-                        'The create snapshot button should be disabled')
+        self.assertIn('disabled', snapshot_action.classes,
+                      'The create snapshot button should be disabled')
 
     @test.create_stubs({cinder: ('tenant_absolute_limits',
                                  'volume_list_paged',
@@ -1224,8 +1224,8 @@ class VolumeViewTests(test.TestCase):
         self.assertItemsEqual(volumes, self.cinder_volumes.list())
 
         create_action = self.getAndAssertTableAction(res, 'volumes', 'create')
-        self.assertTrue('disabled' in create_action.classes,
-                        'The create button should be disabled')
+        self.assertIn('disabled', create_action.classes,
+                      'The create button should be disabled')
 
     @test.create_stubs({cinder: ('tenant_absolute_limits',
                                  'volume_get',