diff --git a/nova/tests/unit/test_nova_manage.py b/nova/tests/unit/test_nova_manage.py
index 6f04e1a3d432..f101e6d9b6dc 100644
--- a/nova/tests/unit/test_nova_manage.py
+++ b/nova/tests/unit/test_nova_manage.py
@@ -13,12 +13,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from six.moves import StringIO
 import sys
 
 import fixtures
 import mock
 from oslo_utils import uuidutils
+from six.moves import StringIO
 
 from nova.cmd import manage
 from nova import conf
diff --git a/nova/tests/unit/test_signature_utils.py b/nova/tests/unit/test_signature_utils.py
index 54c5b93c8e04..69acee1c63be 100644
--- a/nova/tests/unit/test_signature_utils.py
+++ b/nova/tests/unit/test_signature_utils.py
@@ -15,7 +15,6 @@
 
 import base64
 import datetime
-import mock
 
 from castellan.common.exception import KeyManagerError
 import cryptography.exceptions as crypto_exceptions
@@ -24,6 +23,7 @@ from cryptography.hazmat.primitives.asymmetric import dsa
 from cryptography.hazmat.primitives.asymmetric import ec
 from cryptography.hazmat.primitives.asymmetric import padding
 from cryptography.hazmat.primitives.asymmetric import rsa
+import mock
 from oslo_utils import timeutils
 
 from nova import exception
diff --git a/nova/tests/unit/test_uuid_sentinels.py b/nova/tests/unit/test_uuid_sentinels.py
index d838802b6748..e40c5b1a7687 100644
--- a/nova/tests/unit/test_uuid_sentinels.py
+++ b/nova/tests/unit/test_uuid_sentinels.py
@@ -10,9 +10,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import testtools
-
 from oslo_utils import uuidutils
+import testtools
 
 from nova.tests import uuidsentinel
 
diff --git a/nova/tests/unit/virt/libvirt/test_migration.py b/nova/tests/unit/virt/libvirt/test_migration.py
index aa3c1d05bf2d..b0243b8fcbb5 100644
--- a/nova/tests/unit/virt/libvirt/test_migration.py
+++ b/nova/tests/unit/virt/libvirt/test_migration.py
@@ -13,13 +13,12 @@
 #    under the License.
 
 from collections import deque
+
 from lxml import etree
 import mock
-from oslo_utils import units
-
-import six
-
 from oslo_utils import encodeutils
+from oslo_utils import units
+import six
 
 from nova.compute import power_state
 from nova import objects
diff --git a/nova/tests/unit/virt/libvirt/volume/test_disco.py b/nova/tests/unit/virt/libvirt/volume/test_disco.py
index 9556eec2f30a..f2348150952f 100644
--- a/nova/tests/unit/virt/libvirt/volume/test_disco.py
+++ b/nova/tests/unit/virt/libvirt/volume/test_disco.py
@@ -14,7 +14,6 @@
 #    under the License.
 
 import mock
-
 from os_brick.initiator import connector
 
 from nova.tests.unit.virt.libvirt.volume import test_volume
diff --git a/nova/tests/unit/virt/libvirt/volume/test_hgst.py b/nova/tests/unit/virt/libvirt/volume/test_hgst.py
index 38879b1d095a..06345a486d96 100644
--- a/nova/tests/unit/virt/libvirt/volume/test_hgst.py
+++ b/nova/tests/unit/virt/libvirt/volume/test_hgst.py
@@ -14,7 +14,6 @@
 # under the License.
 
 import mock
-
 from os_brick.initiator import connector
 
 from nova.tests.unit.virt.libvirt.volume import test_volume
diff --git a/nova/tests/unit/virt/libvirt/volume/test_quobyte.py b/nova/tests/unit/virt/libvirt/volume/test_quobyte.py
index 8d16cad9cedf..565600595578 100644
--- a/nova/tests/unit/virt/libvirt/volume/test_quobyte.py
+++ b/nova/tests/unit/virt/libvirt/volume/test_quobyte.py
@@ -14,9 +14,9 @@
 #    under the License.
 """Unit tests for the Quobyte volume driver module."""
 
-import mock
 import os
 
+import mock
 from oslo_concurrency import processutils
 from oslo_utils import fileutils
 
diff --git a/nova/tests/unit/virt/xenapi/plugins/plugin_test.py b/nova/tests/unit/virt/xenapi/plugins/plugin_test.py
index 5a2702bbd8be..c08cac541187 100644
--- a/nova/tests/unit/virt/xenapi/plugins/plugin_test.py
+++ b/nova/tests/unit/virt/xenapi/plugins/plugin_test.py
@@ -14,10 +14,11 @@
 #    under the License.
 
 import imp
-import mock
 import os
 import sys
 
+import mock
+
 from nova import test
 from nova.virt.xenapi.client import session
 
diff --git a/nova/tests/unit/virt/xenapi/test_vmops.py b/nova/tests/unit/virt/xenapi/test_vmops.py
index de06e0ab74c8..7fc7bd1914c1 100644
--- a/nova/tests/unit/virt/xenapi/test_vmops.py
+++ b/nova/tests/unit/virt/xenapi/test_vmops.py
@@ -13,8 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from eventlet import greenthread
-import mock
 import uuid
 
 try:
@@ -22,6 +20,9 @@ try:
 except ImportError:
     import six.moves.xmlrpc_client as xmlrpclib
 
+from eventlet import greenthread
+import mock
+
 from nova.compute import power_state
 from nova.compute import task_states
 from nova import context
diff --git a/nova/virt/disk/vfs/guestfs.py b/nova/virt/disk/vfs/guestfs.py
index 2e4e58550eb0..3b4008068e6c 100644
--- a/nova/virt/disk/vfs/guestfs.py
+++ b/nova/virt/disk/vfs/guestfs.py
@@ -12,8 +12,9 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from eventlet import tpool
 import os
+
+from eventlet import tpool
 from oslo_log import log as logging
 from oslo_utils import importutils
 import six
diff --git a/nova/virt/hyperv/vif.py b/nova/virt/hyperv/vif.py
index 8a2319b89515..71b2a9da2d10 100644
--- a/nova/virt/hyperv/vif.py
+++ b/nova/virt/hyperv/vif.py
@@ -16,9 +16,10 @@
 
 import abc
 
-import nova.conf
 from os_win import utilsfactory
 
+import nova.conf
+
 CONF = nova.conf.CONF
 
 
diff --git a/tools/xenserver/populate_other_config.py b/tools/xenserver/populate_other_config.py
index fcd08bc79a8a..f99ed29816e9 100644
--- a/tools/xenserver/populate_other_config.py
+++ b/tools/xenserver/populate_other_config.py
@@ -37,12 +37,13 @@ possible_topdir = os.getcwd()
 if os.path.exists(os.path.join(possible_topdir, "nova", "__init__.py")):
         sys.path.insert(0, possible_topdir)
 
+from oslo_config import cfg
+from oslo_utils import uuidutils
+
 from nova import config
 from nova.virt import virtapi
 from nova.virt.xenapi import driver as xenapi_driver
 from nova.virt.xenapi import vm_utils
-from oslo_config import cfg
-from oslo_utils import uuidutils
 
 cli_opts = [
     cfg.BoolOpt('dry-run',
diff --git a/tools/xenserver/vm_vdi_cleaner.py b/tools/xenserver/vm_vdi_cleaner.py
index 0526d4eb170c..09b172e85e7d 100755
--- a/tools/xenserver/vm_vdi_cleaner.py
+++ b/tools/xenserver/vm_vdi_cleaner.py
@@ -21,6 +21,7 @@ import os
 import sys
 
 from oslo_config import cfg
+from oslo_utils import timeutils
 import XenAPI
 
 possible_topdir = os.getcwd()
@@ -32,7 +33,6 @@ from nova import context
 import nova.conf
 from nova import db
 from nova import exception
-from oslo_utils import timeutils
 from nova.virt import virtapi
 from nova.virt.xenapi import driver as xenapi_driver