Start enforcing additional pylint checks

There were a number of checks disabled in .pylintrc
that can just be removed. There were a few others
that required some small code changes:

    expression-not-assigned
    consider-merging-isinstance
    consider-using-ternary

TrivialFix

Change-Id: I5b4f449a0d7f7653ec0349f0806288c4b21d44f9

.pylintrc

@@ -20,8 +20,6 @@ disable=
 # "F" Fatal errors that prevent further processing
  import-error,
 # "I" Informational noise
- c-extension-no-member,
- locally-disabled,
 # "E" Error for important programming issues (likely bugs)
  access-member-before-definition,
  no-member,
@@ -34,7 +32,6 @@ disable=
  arguments-differ,
  attribute-defined-outside-init,
  broad-except,
- expression-not-assigned,
  fixme,
  global-statement,
  not-callable,
@@ -52,13 +49,11 @@ disable=
  arguments-renamed,
  broad-exception-raised,
  unspecified-encoding,
- redundant-u-string-prefix,
  unused-private-member,
 # "C" Coding convention violations
  consider-iterating-dictionary,
  consider-using-enumerate,
  invalid-name,
- len-as-condition,
  missing-docstring,
  singleton-comparison,
  superfluous-parens,
@@ -67,14 +62,11 @@ disable=
  consider-using-f-string,
  consider-using-dict-items,
 # "R" Refactor recommendations
- consider-merging-isinstance,
- consider-using-ternary,
  duplicate-code,
  inconsistent-return-statements,
  no-else-return,
  no-self-use,
  redefined-argument-from-local,
- simplifiable-if-statement,
  too-few-public-methods,
  too-many-ancestors,
  too-many-arguments,
@@ -86,7 +78,6 @@ disable=
  too-many-public-methods,
  too-many-return-statements,
  too-many-statements,
- consider-using-set-comprehension,
  use-dict-literal
 
 [BASIC]

neutron/agent/l3/ha_router.py

@@ -149,10 +149,7 @@ class HaRouter(router.RouterInfo):
         """this method is normally called before the ha_router object is fully
         initialized
         """
-        if self.router.get('_ha_state') == 'active':
-            return True
-        else:
-            return False
+        return bool(self.router.get('_ha_state') == 'active')
 
     def initialize(self, process_monitor):
         ha_port = self.router.get(n_consts.HA_INTERFACE_KEY)

neutron/db/agentschedulers_db.py

@@ -13,6 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import collections
 import datetime
 import secrets
 import time
@@ -501,9 +502,10 @@ class DhcpAgentSchedulerDbMixin(dhcpagentscheduler
         network_ids = {s.network_id for s in subnets}
 
         # pre-compute net-id per segments.
-        netsegs = {}
-        [netsegs.setdefault(s['network_id'], []).append(s)
-         for s in segments if 'network_id' in s]
+        netsegs = collections.defaultdict(list)
+        for s in segments:
+            if 'network_id' in s:
+                netsegs[s['network_id']].append(s)
         for network_id in network_ids:
             for segment in netsegs.get(network_id, []):
                 self._schedule_network(

neutron/objects/base.py

@@ -227,8 +227,9 @@ class NeutronObject(obj_base.VersionedObject,
 
     @classmethod
     def is_object_field(cls, field):
-        return (isinstance(cls.fields[field], obj_fields.ListOfObjectsField) or
-                isinstance(cls.fields[field], obj_fields.ObjectField))
+        return isinstance(
+                   cls.fields[field],
+                   (obj_fields.ListOfObjectsField, obj_fields.ObjectField))
 
     @classmethod
     def obj_class_from_name(cls, objname, objver):