diff --git a/.pylintrc b/.pylintrc
index ab90f25137c..4cd37c328a0 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -56,13 +56,10 @@ disable=
  raise-missing-from,
  arguments-renamed,
  broad-exception-raised,
- modified-iterating-list,
  unspecified-encoding,
  missing-timeout,
- implicit-str-concat,
  redundant-u-string-prefix,
  unused-private-member,
- global-variable-not-assigned,
 # "C" Coding convention violations
  consider-iterating-dictionary,
  consider-using-enumerate,
diff --git a/neutron/agent/linux/iptables_firewall.py b/neutron/agent/linux/iptables_firewall.py
index b925ba2ee65..246c51858ad 100644
--- a/neutron/agent/linux/iptables_firewall.py
+++ b/neutron/agent/linux/iptables_firewall.py
@@ -731,7 +731,7 @@ class IptablesFirewallDriver(firewall.FirewallDriver):
 
     def _drop_invalid_packets(self, iptables_rules):
         # Always drop invalid packets
-        iptables_rules += [comment_rule('-m state --state ' 'INVALID -j DROP',
+        iptables_rules += [comment_rule('-m state --state INVALID -j DROP',
                                         comment=ic.INVALID_DROP)]
         return iptables_rules
 
diff --git a/neutron/common/utils.py b/neutron/common/utils.py
index 31e562c4b51..7adc9f424d3 100644
--- a/neutron/common/utils.py
+++ b/neutron/common/utils.py
@@ -772,7 +772,7 @@ def attach_exc_details(e, msg, args=_NO_ARGS_MARKER):
 def extract_exc_details(e):
     for attr in ('_error_context_msg', '_error_context_args'):
         if not hasattr(e, attr):
-            return u'No details.'
+            return 'No details.'
     details = e._error_context_msg
     args = e._error_context_args
     if args is _NO_ARGS_MARKER:
diff --git a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_db_sync.py b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_db_sync.py
index dce6c8490a0..29475a020f0 100644
--- a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_db_sync.py
+++ b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_db_sync.py
@@ -284,7 +284,7 @@ class OvnNbSynchronizer(OvnDbSynchronizer):
 
         # Remove the common ones
         for na in list(neutron_acls):
-            for ovn_a in ovn_acls:
+            for ovn_a in ovn_acls.copy():
                 if all(item in na.items() for item in ovn_a.items()):
                     neutron_acls.remove(na)
                     ovn_acls.remove(ovn_a)
diff --git a/neutron/services/trunk/drivers/openvswitch/agent/driver.py b/neutron/services/trunk/drivers/openvswitch/agent/driver.py
index c24ac62d2bc..68e43422090 100644
--- a/neutron/services/trunk/drivers/openvswitch/agent/driver.py
+++ b/neutron/services/trunk/drivers/openvswitch/agent/driver.py
@@ -104,8 +104,5 @@ def init_handler(resource, event, trigger, payload=None):
 
 def unregister():
     """Cleanup fanout queues"""
-    global TRUNK_SKELETON
-    try:
+    if TRUNK_SKELETON:
         TRUNK_SKELETON.unregister()
-    except AttributeError:
-        pass