Fixes 'not in' operator usage

Change-Id: I1e26a8fcb9fa564308e63c11a72aaa55119e4eee

30 files changed, 65 insertions, 53 deletions

diff --git a/HACKING.rst b/HACKING.rst
index 35493e55b..54e3b3275 100644
--- a/HACKING.rst
+++ b/HACKING.rst
@@ -29,6 +29,18 @@ General
     mylist = Foo().list() # OKAY, does not shadow built-in
 
 
+- Use the "not in" operator for collection membership evaluation. Example::
+
+    if not X in Y:  # BAD, hard to understand
+        pass
+
+    if X not in Y:  # OKAY, intuitive
+        pass
+
+    if not (X in Y or X is Z):  # OKAY, still better than all those 'not's
+        pass
+
+
 Imports
 -------
 - Do not import objects, only modules (*)
diff --git a/nova/api/ec2/cloud.py b/nova/api/ec2/cloud.py
index 48b0f632f..8628d0852 100644
--- a/nova/api/ec2/cloud.py
+++ b/nova/api/ec2/cloud.py
@@ -280,7 +280,7 @@ class CloudController(object):
         host_services = {}
         for service in enabled_services:
             zone_hosts.setdefault(service['availability_zone'], [])
-            if not service['host'] in zone_hosts[service['availability_zone']]:
+            if service['host'] not in zone_hosts[service['availability_zone']]:
                 zone_hosts[service['availability_zone']].append(
                     service['host'])
 
@@ -527,7 +527,7 @@ class CloudController(object):
 
     def _rule_args_to_dict(self, context, kwargs):
         rules = []
-        if not 'groups' in kwargs and not 'ip_ranges' in kwargs:
+        if 'groups' not in kwargs and 'ip_ranges' not in kwargs:
             rule = self._rule_dict_last_step(context, **kwargs)
             if rule:
                 rules.append(rule)
@@ -1545,11 +1545,11 @@ class CloudController(object):
         if attribute != 'launchPermission':
             raise exception.EC2APIError(_('attribute not supported: %s')
                                      % attribute)
-        if not 'user_group' in kwargs:
+        if 'user_group' not in kwargs:
             raise exception.EC2APIError(_('user or group not specified'))
         if len(kwargs['user_group']) != 1 and kwargs['user_group'][0] != 'all':
             raise exception.EC2APIError(_('only group "all" is supported'))
-        if not operation_type in ['add', 'remove']:
+        if operation_type not in ['add', 'remove']:
             msg = _('operation_type must be add or remove')
             raise exception.EC2APIError(msg)
         LOG.audit(_("Updating image %s publicity"), image_id, context=context)
diff --git a/nova/api/openstack/__init__.py b/nova/api/openstack/__init__.py
index d812cef18..a76b74324 100644
--- a/nova/api/openstack/__init__.py
+++ b/nova/api/openstack/__init__.py
@@ -102,7 +102,7 @@ class APIMapper(routes.Mapper):
 
 class ProjectMapper(APIMapper):
     def resource(self, member_name, collection_name, **kwargs):
-        if not ('parent_resource' in kwargs):
+        if 'parent_resource' not in kwargs:
             kwargs['path_prefix'] = '{project_id}/'
         else:
             parent_resource = kwargs['parent_resource']
diff --git a/nova/api/openstack/compute/contrib/aggregates.py b/nova/api/openstack/compute/contrib/aggregates.py
index 91d138be4..84b0358a3 100644
--- a/nova/api/openstack/compute/contrib/aggregates.py
+++ b/nova/api/openstack/compute/contrib/aggregates.py
@@ -106,7 +106,7 @@ class AggregateController(object):
             raise exc.HTTPBadRequest
 
         for key in updates.keys():
-            if not key in ["name", "availability_zone"]:
+            if key not in ["name", "availability_zone"]:
                 raise exc.HTTPBadRequest
 
         try:
diff --git a/nova/api/openstack/compute/contrib/availability_zone.py b/nova/api/openstack/compute/contrib/availability_zone.py
index 6cde5ca64..98c508bd7 100644
--- a/nova/api/openstack/compute/contrib/availability_zone.py
+++ b/nova/api/openstack/compute/contrib/availability_zone.py
@@ -110,7 +110,7 @@ class AvailabilityZoneController(wsgi.Controller):
         host_services = {}
         for service in enabled_services:
             zone_hosts.setdefault(service['availability_zone'], [])
-            if not service['host'] in zone_hosts[service['availability_zone']]:
+            if service['host'] not in zone_hosts[service['availability_zone']]:
                 zone_hosts[service['availability_zone']].append(
                     service['host'])
 
diff --git a/nova/api/openstack/compute/contrib/flavorextraspecs.py b/nova/api/openstack/compute/contrib/flavorextraspecs.py
index 84f157b6a..12cc7d9ed 100644
--- a/nova/api/openstack/compute/contrib/flavorextraspecs.py
+++ b/nova/api/openstack/compute/contrib/flavorextraspecs.py
@@ -84,7 +84,7 @@ class FlavorExtraSpecsController(object):
         context = req.environ['nova.context']
         authorize(context)
         self._check_body(body)
-        if not id in body:
+        if id not in body:
             expl = _('Request body and URI mismatch')
             raise exc.HTTPBadRequest(explanation=expl)
         if len(body) > 1:
diff --git a/nova/api/openstack/compute/contrib/floating_ips_bulk.py b/nova/api/openstack/compute/contrib/floating_ips_bulk.py
index f5b8d24dd..db506a15d 100644
--- a/nova/api/openstack/compute/contrib/floating_ips_bulk.py
+++ b/nova/api/openstack/compute/contrib/floating_ips_bulk.py
@@ -80,13 +80,13 @@ class FloatingIPBulkController(object):
         context = req.environ['nova.context']
         authorize(context)
 
-        if not 'floating_ips_bulk_create' in body:
+        if 'floating_ips_bulk_create' not in body:
             raise webob.exc.HTTPUnprocessableEntity()
         params = body['floating_ips_bulk_create']
 
         LOG.debug(params)
 
-        if not 'ip_range' in params:
+        if 'ip_range' not in params:
             raise webob.exc.HTTPUnprocessableEntity()
         ip_range = params['ip_range']
 
diff --git a/nova/api/openstack/compute/contrib/simple_tenant_usage.py b/nova/api/openstack/compute/contrib/simple_tenant_usage.py
index 8502e93c4..2313c00ac 100644
--- a/nova/api/openstack/compute/contrib/simple_tenant_usage.py
+++ b/nova/api/openstack/compute/contrib/simple_tenant_usage.py
@@ -159,7 +159,7 @@ class SimpleTenantUsageController(object):
 
             info['uptime'] = delta.days * 24 * 3600 + delta.seconds
 
-            if not info['tenant_id'] in rval:
+            if info['tenant_id'] not in rval:
                 summary = {}
                 summary['tenant_id'] = info['tenant_id']
                 if detailed:
diff --git a/nova/api/openstack/compute/image_metadata.py b/nova/api/openstack/compute/image_metadata.py
index 1a467f3a7..7e78d6324 100644
--- a/nova/api/openstack/compute/image_metadata.py
+++ b/nova/api/openstack/compute/image_metadata.py
@@ -76,7 +76,7 @@ class Controller(object):
             expl = _('Incorrect request body format')
             raise exc.HTTPBadRequest(explanation=expl)
 
-        if not id in meta:
+        if id not in meta:
             expl = _('Request body and URI mismatch')
             raise exc.HTTPBadRequest(explanation=expl)
         if len(meta) > 1:
@@ -105,7 +105,7 @@ class Controller(object):
     def delete(self, req, image_id, id):
         context = req.environ['nova.context']
         image = self._get_image(context, image_id)
-        if not id in image['properties']:
+        if id not in image['properties']:
             msg = _("Invalid metadata key")
             raise exc.HTTPNotFound(explanation=msg)
         image['properties'].pop(id)
diff --git a/nova/api/openstack/compute/servers.py b/nova/api/openstack/compute/servers.py
index 90d4c37b3..ac4ebd293 100644
--- a/nova/api/openstack/compute/servers.py
+++ b/nova/api/openstack/compute/servers.py
@@ -751,7 +751,7 @@ class Controller(wsgi.Controller):
         server_dict = body['server']
         password = self._get_server_admin_password(server_dict)
 
-        if not 'name' in server_dict:
+        if 'name' not in server_dict:
             msg = _("Server name is not defined")
             raise exc.HTTPBadRequest(explanation=msg)
 
diff --git a/nova/api/openstack/wsgi.py b/nova/api/openstack/wsgi.py
index a6f255081..f68eff2a7 100644
--- a/nova/api/openstack/wsgi.py
+++ b/nova/api/openstack/wsgi.py
@@ -150,7 +150,7 @@ class Request(webob.Request):
         Does not do any body introspection, only checks header
 
         """
-        if not "Content-Type" in self.headers:
+        if "Content-Type" not in self.headers:
             return None
 
         content_type = self.content_type
diff --git a/nova/availability_zones.py b/nova/availability_zones.py
index 711eee1fa..97faccc9f 100644
--- a/nova/availability_zones.py
+++ b/nova/availability_zones.py
@@ -71,7 +71,7 @@ def get_availability_zones(context):
     available_zones = []
     for zone in [service['availability_zone'] for service
                  in enabled_services]:
-        if not zone in available_zones:
+        if zone not in available_zones:
             available_zones.append(zone)
 
     not_available_zones = []
diff --git a/nova/compute/vm_mode.py b/nova/compute/vm_mode.py
index 26e5ad8a0..cc1ca6978 100644
--- a/nova/compute/vm_mode.py
+++ b/nova/compute/vm_mode.py
@@ -52,7 +52,7 @@ def get_from_instance(instance):
     if mode == "hv":
         mode = HVM
 
-    if not mode in ALL:
+    if mode not in ALL:
         raise exception.Invalid("Unknown vm mode '%s'" % mode)
 
     return mode
diff --git a/nova/scheduler/filters/trusted_filter.py b/nova/scheduler/filters/trusted_filter.py
index 302d2b3a8..14f1a37b0 100644
--- a/nova/scheduler/filters/trusted_filter.py
+++ b/nova/scheduler/filters/trusted_filter.py
@@ -269,7 +269,7 @@ class ComputeAttestationCache(object):
 
     def get_host_attestation(self, host):
         """Check host's trust level."""
-        if not host in self.compute_nodes:
+        if host not in self.compute_nodes:
             self._init_cache_entry(host)
         if not self._cache_valid(host):
             self._update_cache()
diff --git a/nova/service.py b/nova/service.py
index 2daceba80..3d556a202 100644
--- a/nova/service.py
+++ b/nova/service.py
@@ -621,7 +621,7 @@ class WSGIService(object):
 
         """
         fl = '%s_manager' % self.name
-        if not fl in CONF:
+        if fl not in CONF:
             return None
 
         manager_class_name = CONF.get(fl, None)
diff --git a/nova/tests/api/openstack/fakes.py b/nova/tests/api/openstack/fakes.py
index 03fc87ac5..857644498 100644
--- a/nova/tests/api/openstack/fakes.py
+++ b/nova/tests/api/openstack/fakes.py
@@ -372,7 +372,7 @@ def create_info_cache(nw_cache):
 
 
 def get_fake_uuid(token=0):
-    if not token in FAKE_UUIDS:
+    if token not in FAKE_UUIDS:
         FAKE_UUIDS[token] = str(uuid.uuid4())
     return FAKE_UUIDS[token]
 
diff --git a/nova/tests/compute/test_resource_tracker.py b/nova/tests/compute/test_resource_tracker.py
index 53d92a13f..eaa0df5bf 100644
--- a/nova/tests/compute/test_resource_tracker.py
+++ b/nova/tests/compute/test_resource_tracker.py
@@ -391,7 +391,7 @@ class BaseTrackerTestCase(BaseTestCase):
         if tracker is None:
             tracker = self.tracker
 
-        if not field in tracker.compute_node:
+        if field not in tracker.compute_node:
             raise test.TestingException(
                 "'%(field)s' not in compute node." % locals())
         x = tracker.compute_node[field]
diff --git a/nova/tests/fakeguestfs.py b/nova/tests/fakeguestfs.py
index 33ca49c33..ff006db68 100644
--- a/nova/tests/fakeguestfs.py
+++ b/nova/tests/fakeguestfs.py
@@ -50,7 +50,7 @@ class GuestFS(object):
         self.mounts.append((options, device, mntpoint))
 
     def mkdir_p(self, path):
-        if not path in self.files:
+        if path not in self.files:
             self.files[path] = {
                 "isdir": True,
                 "gid": 100,
@@ -59,7 +59,7 @@ class GuestFS(object):
                 }
 
     def read_file(self, path):
-        if not path in self.files:
+        if path not in self.files:
             self.files[path] = {
                 "isdir": False,
                 "content": "Hello World",
@@ -71,7 +71,7 @@ class GuestFS(object):
         return self.files[path]["content"]
 
     def write(self, path, content):
-        if not path in self.files:
+        if path not in self.files:
             self.files[path] = {
                 "isdir": False,
                 "content": "Hello World",
@@ -83,7 +83,7 @@ class GuestFS(object):
         self.files[path]["content"] = content
 
     def write_append(self, path, content):
-        if not path in self.files:
+        if path not in self.files:
             self.files[path] = {
                 "isdir": False,
                 "content": "Hello World",
@@ -95,13 +95,13 @@ class GuestFS(object):
         self.files[path]["content"] = self.files[path]["content"] + content
 
     def stat(self, path):
-        if not path in self.files:
+        if path not in self.files:
             raise RuntimeError("No such file: " + path)
 
         return self.files[path]["mode"]
 
     def chown(self, uid, gid, path):
-        if not path in self.files:
+        if path not in self.files:
             raise RuntimeError("No such file: " + path)
 
         if uid != -1:
@@ -110,7 +110,7 @@ class GuestFS(object):
             self.files[path]["gid"] = gid
 
     def chmod(self, mode, path):
-        if not path in self.files:
+        if path not in self.files:
             raise RuntimeError("No such file: " + path)
 
         self.files[path]["mode"] = mode
diff --git a/nova/tests/integrated/api/client.py b/nova/tests/integrated/api/client.py
index a072b3128..958a5500b 100644
--- a/nova/tests/integrated/api/client.py
+++ b/nova/tests/integrated/api/client.py
@@ -155,7 +155,7 @@ class TestOpenStackClient(object):
         LOG.debug(_("%(relative_uri)s => code %(http_status)s") % locals())
 
         if check_response_status:
-            if not http_status in check_response_status:
+            if http_status not in check_response_status:
                 if http_status == 404:
                     raise OpenStackApiNotFoundException(response=response)
                 elif http_status == 401:
diff --git a/nova/tests/integrated/integrated_helpers.py b/nova/tests/integrated/integrated_helpers.py
index f17dc025f..90e9a806e 100644
--- a/nova/tests/integrated/integrated_helpers.py
+++ b/nova/tests/integrated/integrated_helpers.py
@@ -58,7 +58,7 @@ def generate_new_element(items, prefix, numeric=False):
             candidate = prefix + generate_random_numeric(8)
         else:
             candidate = prefix + generate_random_alphanumeric(8)
-        if not candidate in items:
+        if candidate not in items:
             return candidate
         LOG.debug("Random collision on %s" % candidate)
 
diff --git a/nova/tests/test_libvirt.py b/nova/tests/test_libvirt.py
index 72c886529..6e7986b0e 100644
--- a/nova/tests/test_libvirt.py
+++ b/nova/tests/test_libvirt.py
@@ -3848,7 +3848,7 @@ class IptablesFirewallTestCase(test.TestCase):
         in_rules = filter(lambda l: not l.startswith('#'),
                           self.in_rules)
         for rule in in_rules:
-            if not 'nova' in rule:
+            if 'nova' not in rule:
                 self.assertTrue(rule in self.out_rules,
                                 'Rule went missing: %s' % rule)
 
diff --git a/nova/tests/test_virt_disk_vfs_localfs.py b/nova/tests/test_virt_disk_vfs_localfs.py
index af4571dd2..096a75964 100644
--- a/nova/tests/test_virt_disk_vfs_localfs.py
+++ b/nova/tests/test_virt_disk_vfs_localfs.py
@@ -46,7 +46,7 @@ def fake_execute(*args, **kwargs):
     elif args[0] == "chown":
         owner = args[1]
         path = args[2]
-        if not path in files:
+        if path not in files:
             raise Exception("No such file: " + path)
 
         sep = owner.find(':')
@@ -72,7 +72,7 @@ def fake_execute(*args, **kwargs):
     elif args[0] == "chgrp":
         group = args[1]
         path = args[2]
-        if not path in files:
+        if path not in files:
             raise Exception("No such file: " + path)
 
         if group == "users":
@@ -83,13 +83,13 @@ def fake_execute(*args, **kwargs):
     elif args[0] == "chmod":
         mode = args[1]
         path = args[2]
-        if not path in files:
+        if path not in files:
             raise Exception("No such file: " + path)
 
         files[path]["mode"] = int(mode, 8)
     elif args[0] == "cat":
         path = args[1]
-        if not path in files:
+        if path not in files:
             files[path] = {
                 "content": "Hello World",
                 "gid": 100,
@@ -104,7 +104,7 @@ def fake_execute(*args, **kwargs):
         else:
             path = args[1]
             append = False
-        if not path in files:
+        if path not in files:
             files[path] = {
                 "content": "Hello World",
                 "gid": 100,
diff --git a/nova/tests/test_xenapi.py b/nova/tests/test_xenapi.py
index aa640810b..c480d5c5f 100644
--- a/nova/tests/test_xenapi.py
+++ b/nova/tests/test_xenapi.py
@@ -595,7 +595,7 @@ class XenAPIVMTestCase(stubs.XenAPITestBase):
 
     def _check_vdis(self, start_list, end_list):
         for vdi_ref in end_list:
-            if not vdi_ref in start_list:
+            if vdi_ref not in start_list:
                 vdi_rec = xenapi_fake.get_record('VDI', vdi_ref)
                 # If the cache is turned on then the base disk will be
                 # there even after the cleanup
@@ -1949,7 +1949,7 @@ class XenAPIDom0IptablesFirewallTestCase(stubs.XenAPITestBase):
         in_rules = filter(lambda l: not l.startswith('#'),
                           self._in_rules)
         for rule in in_rules:
-            if not 'nova' in rule:
+            if 'nova' not in rule:
                 self.assertTrue(rule in self._out_rules,
                                 'Rule went missing: %s' % rule)
 
diff --git a/nova/virt/baremetal/driver.py b/nova/virt/baremetal/driver.py
index 9904fdcd4..631a9a8c4 100644
--- a/nova/virt/baremetal/driver.py
+++ b/nova/virt/baremetal/driver.py
@@ -140,7 +140,7 @@ class BareMetalDriver(driver.ComputeDriver):
             keyval[0] = keyval[0].strip()
             keyval[1] = keyval[1].strip()
             extra_specs[keyval[0]] = keyval[1]
-        if not 'cpu_arch' in extra_specs:
+        if 'cpu_arch' not in extra_specs:
             LOG.warning(
                     _('cpu_arch is not found in instance_type_extra_specs'))
             extra_specs['cpu_arch'] = ''
diff --git a/nova/virt/baremetal/volume_driver.py b/nova/virt/baremetal/volume_driver.py
index 0a05dfedd..e92325b97 100644
--- a/nova/virt/baremetal/volume_driver.py
+++ b/nova/virt/baremetal/volume_driver.py
@@ -210,7 +210,7 @@ class LibvirtVolumeDriver(VolumeDriver):
     def _volume_driver_method(self, method_name, connection_info,
                              *args, **kwargs):
         driver_type = connection_info.get('driver_volume_type')
-        if not driver_type in self.volume_drivers:
+        if driver_type not in self.volume_drivers:
             raise exception.VolumeDriverNotFound(driver_type=driver_type)
         driver = self.volume_drivers[driver_type]
         method = getattr(driver, method_name)
diff --git a/nova/virt/fake.py b/nova/virt/fake.py
index 04eeded72..5a5bb7b13 100644
--- a/nova/virt/fake.py
+++ b/nova/virt/fake.py
@@ -125,7 +125,7 @@ class FakeDriver(driver.ComputeDriver):
         self.instances[name] = fake_instance
 
     def snapshot(self, context, instance, name, update_task_state):
-        if not instance['name'] in self.instances:
+        if instance['name'] not in self.instances:
             raise exception.InstanceNotRunning(instance_id=instance['uuid'])
         update_task_state(task_state=task_states.IMAGE_UPLOADING)
 
@@ -209,7 +209,7 @@ class FakeDriver(driver.ComputeDriver):
     def attach_volume(self, connection_info, instance, mountpoint):
         """Attach the disk to the instance at mountpoint using info."""
         instance_name = instance['name']
-        if not instance_name in self._mounts:
+        if instance_name not in self._mounts:
             self._mounts[instance_name] = {}
         self._mounts[instance_name][mountpoint] = connection_info
         return True
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 9ed7a054c..585074f1f 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -673,7 +673,7 @@ class LibvirtDriver(driver.ComputeDriver):
     def volume_driver_method(self, method_name, connection_info,
                              *args, **kwargs):
         driver_type = connection_info.get('driver_volume_type')
-        if not driver_type in self.volume_drivers:
+        if driver_type not in self.volume_drivers:
             raise exception.VolumeDriverNotFound(driver_type=driver_type)
         driver = self.volume_drivers[driver_type]
         method = getattr(driver, method_name)
diff --git a/nova/virt/libvirt/imagecache.py b/nova/virt/libvirt/imagecache.py
index 8f677b482..3609205ce 100644
--- a/nova/virt/libvirt/imagecache.py
+++ b/nova/virt/libvirt/imagecache.py
@@ -305,7 +305,7 @@ class ImageCacheManager(object):
                         backing_path = os.path.join(CONF.instances_path,
                                                     CONF.base_dir_name,
                                                     backing_file)
-                        if not backing_path in inuse_images:
+                        if backing_path not in inuse_images:
                             inuse_images.append(backing_path)
 
                         if backing_path in self.unexplained_images:
@@ -555,7 +555,7 @@ class ImageCacheManager(object):
         # Elements remaining in unexplained_images might be in use
         inuse_backing_images = self._list_backing_images()
         for backing_path in inuse_backing_images:
-            if not backing_path in self.active_base_files:
+            if backing_path not in self.active_base_files:
                 self.active_base_files.append(backing_path)
 
         # Anything left is an unknown base image
diff --git a/nova/virt/xenapi/fake.py b/nova/virt/xenapi/fake.py
index 666e46754..bdadfbc38 100644
--- a/nova/virt/xenapi/fake.py
+++ b/nova/virt/xenapi/fake.py
@@ -89,7 +89,7 @@ def reset():
 
 
 def reset_table(table):
-    if not table in _CLASSES:
+    if table not in _CLASSES:
         return
     _db_content[table] = {}
 
@@ -417,7 +417,7 @@ class SessionBase(object):
 
     def VBD_add_to_other_config(self, _1, vbd_ref, key, value):
         db_ref = _db_content['VBD'][vbd_ref]
-        if not 'other_config' in db_ref:
+        if 'other_config' not in db_ref:
             db_ref['other_config'] = {}
         if key in db_ref['other_config']:
             raise Failure(['MAP_DUPLICATE_KEY', 'VBD', 'other_config',
@@ -426,7 +426,7 @@ class SessionBase(object):
 
     def VBD_get_other_config(self, _1, vbd_ref):
         db_ref = _db_content['VBD'][vbd_ref]
-        if not 'other_config' in db_ref:
+        if 'other_config' not in db_ref:
             return {}
         return db_ref['other_config']
 
@@ -497,14 +497,14 @@ class SessionBase(object):
 
     def VM_remove_from_xenstore_data(self, _1, vm_ref, key):
         db_ref = _db_content['VM'][vm_ref]
-        if not 'xenstore_data' in db_ref:
+        if 'xenstore_data' not in db_ref:
             return
         if key in db_ref['xenstore_data']:
             del db_ref['xenstore_data'][key]
 
     def VM_add_to_xenstore_data(self, _1, vm_ref, key, value):
         db_ref = _db_content['VM'][vm_ref]
-        if not 'xenstore_data' in db_ref:
+        if 'xenstore_data' not in db_ref:
             db_ref['xenstore_data'] = {}
         db_ref['xenstore_data'][key] = value
 
@@ -513,14 +513,14 @@ class SessionBase(object):
 
     def VDI_remove_from_other_config(self, _1, vdi_ref, key):
         db_ref = _db_content['VDI'][vdi_ref]
-        if not 'other_config' in db_ref:
+        if 'other_config' not in db_ref:
             return
         if key in db_ref['other_config']:
             del db_ref['other_config'][key]
 
     def VDI_add_to_other_config(self, _1, vdi_ref, key, value):
         db_ref = _db_content['VDI'][vdi_ref]
-        if not 'other_config' in db_ref:
+        if 'other_config' not in db_ref:
             db_ref['other_config'] = {}
         if key in db_ref['other_config']:
             raise Failure(['MAP_DUPLICATE_KEY', 'VDI', 'other_config',
diff --git a/nova/virt/xenapi/vm_utils.py b/nova/virt/xenapi/vm_utils.py
index fe4ce9409..6c4c3d4bc 100644
--- a/nova/virt/xenapi/vm_utils.py
+++ b/nova/virt/xenapi/vm_utils.py
@@ -1560,7 +1560,7 @@ def _find_iso_sr(session):
         if not sr_rec['content_type'] == 'iso':
             LOG.debug(_("ISO: not iso content"))
             continue
-        if not 'i18n-key' in sr_rec['other_config']:
+        if 'i18n-key' not in sr_rec['other_config']:
             LOG.debug(_("ISO: iso content_type, no 'i18n-key' key"))
             continue
         if not sr_rec['other_config']['i18n-key'] == 'local-storage-iso':