diff --git a/neutron_tempest_plugin/api/test_dhcp_ipv6.py b/neutron_tempest_plugin/api/test_dhcp_ipv6.py
index 69b4ea0..0fab75c 100644
--- a/neutron_tempest_plugin/api/test_dhcp_ipv6.py
+++ b/neutron_tempest_plugin/api/test_dhcp_ipv6.py
@@ -58,8 +58,8 @@
         ports = body['ports']
         for port in ports:
             if (port['device_owner'].startswith(
-                    constants.DEVICE_OWNER_ROUTER_INTF)
-                and port['device_id'] in [r['id'] for r in self.routers]):
+                    constants.DEVICE_OWNER_ROUTER_INTF) and
+                port['device_id'] in [r['id'] for r in self.routers]):
                 self.client.remove_router_interface_with_port_id(
                     port['device_id'], port['id']
                 )
diff --git a/neutron_tempest_plugin/api/test_network_ip_availability.py b/neutron_tempest_plugin/api/test_network_ip_availability.py
index ed56363..10aee2e 100644
--- a/neutron_tempest_plugin/api/test_network_ip_availability.py
+++ b/neutron_tempest_plugin/api/test_network_ip_availability.py
@@ -79,11 +79,11 @@
 def calc_total_ips(prefix, ip_version):
     # will calculate total ips after removing reserved.
     if ip_version == lib_constants.IP_VERSION_4:
-        total_ips = 2 ** (lib_constants.IPv4_BITS
-                          - prefix) - DEFAULT_IP4_RESERVED
+        total_ips = 2 ** (lib_constants.IPv4_BITS -
+                          prefix) - DEFAULT_IP4_RESERVED
     elif ip_version == lib_constants.IP_VERSION_6:
-        total_ips = 2 ** (lib_constants.IPv6_BITS
-                          - prefix) - DEFAULT_IP6_RESERVED
+        total_ips = 2 ** (lib_constants.IPv6_BITS -
+                          prefix) - DEFAULT_IP6_RESERVED
     return total_ips
 
 
diff --git a/neutron_tempest_plugin/api/test_routers.py b/neutron_tempest_plugin/api/test_routers.py
index bc657e0..d5d2e04 100644
--- a/neutron_tempest_plugin/api/test_routers.py
+++ b/neutron_tempest_plugin/api/test_routers.py
@@ -159,9 +159,12 @@
         # Add router interface with subnet id
         router = self._create_router(data_utils.rand_name('router'), True)
         intf = self.create_router_interface(router['id'], subnet['id'])
-        status_active = lambda: self.client.show_port(
-            intf['port_id'])['port']['status'] == 'ACTIVE'
-        utils.wait_until_true(status_active, exception=AssertionError)
+
+        def _status_active():
+            return self.client.show_port(
+                intf['port_id'])['port']['status'] == 'ACTIVE'
+
+        utils.wait_until_true(_status_active, exception=AssertionError)
 
     @decorators.idempotent_id('c86ac3a8-50bd-4b00-a6b8-62af84a0765c')
     @tutils.requires_ext(extension='extraroute', service='network')