diff --git a/neutron/db/migration/alembic_migrations/script.py.mako b/neutron/db/migration/alembic_migrations/script.py.mako
index 121181a32cd..b568c22fa7e 100644
--- a/neutron/db/migration/alembic_migrations/script.py.mako
+++ b/neutron/db/migration/alembic_migrations/script.py.mako
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
 """${message}
 
 Revision ID: ${up_revision}
@@ -28,10 +32,6 @@ down_revision = ${repr(down_revision)}
 branch_labels = ${repr(branch_labels)}
 % endif
 
-from alembic import op
-import sqlalchemy as sa
-${imports if imports else ""}
-
 
 def upgrade():
     ${upgrades if upgrades else "pass"}
diff --git a/neutron/db/migration/alembic_migrations/versions/kilo_initial.py b/neutron/db/migration/alembic_migrations/versions/kilo_initial.py
index 5bd9a9528b1..f4290e3e758 100644
--- a/neutron/db/migration/alembic_migrations/versions/kilo_initial.py
+++ b/neutron/db/migration/alembic_migrations/versions/kilo_initial.py
@@ -13,18 +13,6 @@
 #    under the License.
 #
 
-"""kilo_initial
-
-Revision ID: kilo
-Revises: None
-
-"""
-
-# revision identifiers, used by Alembic.
-revision = 'kilo'
-down_revision = None
-
-
 from neutron.db import migration
 from neutron.db.migration.alembic_migrations import agent_init_ops
 from neutron.db.migration.alembic_migrations import brocade_init_ops
@@ -48,6 +36,17 @@ from neutron.db.migration.alembic_migrations import secgroup_init_ops
 from neutron.db.migration.alembic_migrations import vmware_init_ops
 from neutron.db.migration.alembic_migrations import vpn_init_ops
 
+"""kilo_initial
+
+Revision ID: kilo
+Revises: None
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'kilo'
+down_revision = None
+
 
 def upgrade():
     migration.pk_on_alembic_version_table()
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/contract/11926bcfe72d_add_geneve_ml2_type_driver.py b/neutron/db/migration/alembic_migrations/versions/liberty/contract/11926bcfe72d_add_geneve_ml2_type_driver.py
index 39ef3ba967c..761bd484cac 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/contract/11926bcfe72d_add_geneve_ml2_type_driver.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/contract/11926bcfe72d_add_geneve_ml2_type_driver.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """add geneve ml2 type driver
 
 Revision ID: 11926bcfe72d
@@ -25,9 +28,6 @@ Create Date: 2015-08-27 19:56:16.356522
 revision = '11926bcfe72d'
 down_revision = '2e5352a0ad4d'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def contract_creation_exceptions():
     """These elements were created by mistake in the contract branch."""
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/contract/2a16083502f3_metaplugin_removal.py b/neutron/db/migration/alembic_migrations/versions/liberty/contract/2a16083502f3_metaplugin_removal.py
index 802ad7a8cab..2b424f6a0a8 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/contract/2a16083502f3_metaplugin_removal.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/contract/2a16083502f3_metaplugin_removal.py
@@ -13,6 +13,8 @@
 #    under the License.
 #
 
+from alembic import op
+
 """Metaplugin removal
 
 Revision ID: 2a16083502f3
@@ -25,8 +27,6 @@ Create Date: 2015-06-16 09:11:10.488566
 revision = '2a16083502f3'
 down_revision = '5498d17be016'
 
-from alembic import op
-
 
 def upgrade():
     op.drop_table('networkflavors')
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/contract/2e5352a0ad4d_add_missing_foreign_keys.py b/neutron/db/migration/alembic_migrations/versions/liberty/contract/2e5352a0ad4d_add_missing_foreign_keys.py
index 4961514dd62..b02d5208a0d 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/contract/2e5352a0ad4d_add_missing_foreign_keys.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/contract/2e5352a0ad4d_add_missing_foreign_keys.py
@@ -13,6 +13,11 @@
 #    under the License.
 #
 
+from alembic import op
+from sqlalchemy.engine import reflection
+
+from neutron.db import migration
+
 """Add missing foreign keys
 
 Revision ID: 2e5352a0ad4d
@@ -25,11 +30,6 @@ Create Date: 2015-08-20 12:43:09.110427
 revision = '2e5352a0ad4d'
 down_revision = '2a16083502f3'
 
-from alembic import op
-from sqlalchemy.engine import reflection
-
-from neutron.db import migration
-
 
 TABLE_NAME = 'flavorserviceprofilebindings'
 
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/contract/30018084ec99_initial.py b/neutron/db/migration/alembic_migrations/versions/liberty/contract/30018084ec99_initial.py
index 0e6358ffb7e..6b813d0e3ed 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/contract/30018084ec99_initial.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/contract/30018084ec99_initial.py
@@ -11,6 +11,8 @@
 #    under the License.
 #
 
+from neutron.db.migration import cli
+
 """Initial no-op Liberty contract rule.
 
 Revision ID: 30018084ec99
@@ -19,9 +21,6 @@ Create Date: 2015-06-22 00:00:00.000000
 
 """
 
-from neutron.db.migration import cli
-
-
 # revision identifiers, used by Alembic.
 revision = '30018084ec99'
 down_revision = 'kilo'
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/contract/4af11ca47297_drop_cisco_monolithic_tables.py b/neutron/db/migration/alembic_migrations/versions/liberty/contract/4af11ca47297_drop_cisco_monolithic_tables.py
index 7a91b79b31e..bb667acdbdf 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/contract/4af11ca47297_drop_cisco_monolithic_tables.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/contract/4af11ca47297_drop_cisco_monolithic_tables.py
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+
+from neutron.db import migration
+
 """Drop cisco monolithic tables
 
 Revision ID: 4af11ca47297
@@ -21,11 +25,6 @@ Create Date: 2015-08-13 08:01:19.709839
 
 """
 
-from alembic import op
-
-from neutron.db import migration
-
-
 # revision identifiers, used by Alembic.
 revision = '4af11ca47297'
 down_revision = '11926bcfe72d'
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/contract/4ffceebfada_rbac_network.py b/neutron/db/migration/alembic_migrations/versions/liberty/contract/4ffceebfada_rbac_network.py
index 76926fa6a5d..aa09735deb8 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/contract/4ffceebfada_rbac_network.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/contract/4ffceebfada_rbac_network.py
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+from oslo_utils import uuidutils
+import sqlalchemy as sa
+
 """network_rbac
 
 Revision ID: 4ffceebfada
@@ -26,10 +30,6 @@ revision = '4ffceebfada'
 down_revision = '30018084ec99'
 depends_on = ('8675309a5c4f',)
 
-from alembic import op
-from oslo_utils import uuidutils
-import sqlalchemy as sa
-
 
 # A simple model of the networks table with only the fields needed for
 # the migration.
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/contract/5498d17be016_drop_legacy_ovs_and_lb.py b/neutron/db/migration/alembic_migrations/versions/liberty/contract/5498d17be016_drop_legacy_ovs_and_lb.py
index 55ad8d15b5e..623bb6401d4 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/contract/5498d17be016_drop_legacy_ovs_and_lb.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/contract/5498d17be016_drop_legacy_ovs_and_lb.py
@@ -13,6 +13,8 @@
 #    under the License.
 #
 
+from alembic import op
+
 """Drop legacy OVS and LB plugin tables
 
 Revision ID: 5498d17be016
@@ -25,8 +27,6 @@ Create Date: 2015-06-25 14:08:30.984419
 revision = '5498d17be016'
 down_revision = '4ffceebfada'
 
-from alembic import op
-
 
 def upgrade():
     op.drop_table('ovs_network_bindings')
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/1b4c6e320f79_address_scope_support_in_subnetpool.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/1b4c6e320f79_address_scope_support_in_subnetpool.py
index f1ffdafdedb..e3a2159fe37 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/1b4c6e320f79_address_scope_support_in_subnetpool.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/1b4c6e320f79_address_scope_support_in_subnetpool.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """address scope support in subnetpool
 
 Revision ID: 1b4c6e320f79
@@ -25,9 +28,6 @@ Create Date: 2015-07-03 09:48:39.491058
 revision = '1b4c6e320f79'
 down_revision = '1c844d1677f7'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column('subnetpools',
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/1c844d1677f7_dns_nameservers_order.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/1c844d1677f7_dns_nameservers_order.py
index e1781edcad8..e7a922c924d 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/1c844d1677f7_dns_nameservers_order.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/1c844d1677f7_dns_nameservers_order.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """add order to dnsnameservers
 
 Revision ID: 1c844d1677f7
@@ -25,9 +28,6 @@ Create Date: 2015-07-21 22:59:03.383850
 revision = '1c844d1677f7'
 down_revision = '26c371498592'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column('dnsnameservers',
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/26c371498592_subnetpool_hash.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/26c371498592_subnetpool_hash.py
index 5bff7c888a1..9a806eb26f7 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/26c371498592_subnetpool_hash.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/26c371498592_subnetpool_hash.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """subnetpool hash
 
 Revision ID: 26c371498592
@@ -25,9 +28,6 @@ Create Date: 2015-06-02 21:18:19.942076
 revision = '26c371498592'
 down_revision = '45f955889773'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column(
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/31337ec0ffee_flavors.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/31337ec0ffee_flavors.py
index 4ac5ac8063a..aea3ab69363 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/31337ec0ffee_flavors.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/31337ec0ffee_flavors.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Flavor framework
 
 Revision ID: 313373c0ffee
@@ -24,9 +27,6 @@ Create Date: 2014-07-17 03:00:00.00
 revision = '313373c0ffee'
 down_revision = '52c5312f6baf'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table(
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/34af2b5c5a59_add_dns_name_to_port.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/34af2b5c5a59_add_dns_name_to_port.py
index f9aa942d7a3..001846827b7 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/34af2b5c5a59_add_dns_name_to_port.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/34af2b5c5a59_add_dns_name_to_port.py
@@ -13,6 +13,12 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib.db import constants
+import sqlalchemy as sa
+
+from neutron.db import migration
+
 """Add dns_name to Port
 
 Revision ID: 34af2b5c5a59
@@ -21,12 +27,6 @@ Create Date: 2015-08-23 00:22:47.618593
 
 """
 
-from alembic import op
-from neutron_lib.db import constants
-import sqlalchemy as sa
-
-from neutron.db import migration
-
 # revision identifiers, used by Alembic.
 revision = '34af2b5c5a59'
 down_revision = '9859ac9c136'
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/354db87e3225_nsxv_vdr_metadata.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/354db87e3225_nsxv_vdr_metadata.py
index e63b3f5d09b..3b0361b6afe 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/354db87e3225_nsxv_vdr_metadata.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/354db87e3225_nsxv_vdr_metadata.py
@@ -13,6 +13,11 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
+from neutron.db.migration import cli
+
 """nsxv_vdr_metadata.py
 
 Revision ID: 354db87e3225
@@ -21,12 +26,6 @@ Create Date: 2015-04-19 14:59:15.102609
 
 """
 
-from alembic import op
-import sqlalchemy as sa
-
-from neutron.db.migration import cli
-
-
 # revision identifiers, used by Alembic.
 revision = '354db87e3225'
 down_revision = 'kilo'
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/45f955889773_quota_usage.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/45f955889773_quota_usage.py
index e10edc94db6..349353bb52c 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/45f955889773_quota_usage.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/45f955889773_quota_usage.py
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy import sql
+
 """quota_usage
 
 Revision ID: 45f955889773
@@ -25,10 +29,6 @@ Create Date: 2015-04-17 08:09:37.611546
 revision = '45f955889773'
 down_revision = '8675309a5c4f'
 
-from alembic import op
-import sqlalchemy as sa
-from sqlalchemy import sql
-
 
 def upgrade():
     op.create_table(
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/48153cb5f051_qos_db_changes.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/48153cb5f051_qos_db_changes.py
index 0fc966580d5..4a88aa939bf 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/48153cb5f051_qos_db_changes.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/48153cb5f051_qos_db_changes.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """qos db changes
 
 Revision ID: 48153cb5f051
@@ -25,9 +28,6 @@ Create Date: 2015-06-24 17:03:34.965101
 revision = '48153cb5f051'
 down_revision = '1b4c6e320f79'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table(
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/52c5312f6baf_address_scopes.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/52c5312f6baf_address_scopes.py
index 9fa1466e52b..dd7b20a676c 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/52c5312f6baf_address_scopes.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/52c5312f6baf_address_scopes.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Initial operations in support of address scopes
 
 """
@@ -21,9 +24,6 @@
 revision = '52c5312f6baf'
 down_revision = '599c6a226151'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table(
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/599c6a226151_neutrodb_ipam.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/599c6a226151_neutrodb_ipam.py
index cea591d8298..995cb47801c 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/599c6a226151_neutrodb_ipam.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/599c6a226151_neutrodb_ipam.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """neutrodb_ipam
 
 Revision ID: 599c6a226151
@@ -25,9 +28,6 @@ Create Date: 2015-03-08 18:12:08.962378
 revision = '599c6a226151'
 down_revision = '354db87e3225'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table(
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/8675309a5c4f_rbac_network.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/8675309a5c4f_rbac_network.py
index b2c7156e702..49f50e6d196 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/8675309a5c4f_rbac_network.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/8675309a5c4f_rbac_network.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """network_rbac
 
 Revision ID: 8675309a5c4f
@@ -25,9 +28,6 @@ Create Date: 2015-06-14 13:12:04.012457
 revision = '8675309a5c4f'
 down_revision = '313373c0ffee'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table(
diff --git a/neutron/db/migration/alembic_migrations/versions/liberty/expand/9859ac9c136_quota_reservations.py b/neutron/db/migration/alembic_migrations/versions/liberty/expand/9859ac9c136_quota_reservations.py
index c8935a86f13..b9625ad3c31 100644
--- a/neutron/db/migration/alembic_migrations/versions/liberty/expand/9859ac9c136_quota_reservations.py
+++ b/neutron/db/migration/alembic_migrations/versions/liberty/expand/9859ac9c136_quota_reservations.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """quota_reservations
 
 Revision ID: 9859ac9c136
@@ -25,9 +28,6 @@ Create Date: 2015-03-11 06:40:56.775075
 revision = '9859ac9c136'
 down_revision = '48153cb5f051'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table(
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/1b294093239c_remove_embrane_plugin.py b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/1b294093239c_remove_embrane_plugin.py
index 68e6d2576a1..01c90aea0c4 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/1b294093239c_remove_embrane_plugin.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/1b294093239c_remove_embrane_plugin.py
@@ -11,6 +11,8 @@
 #    under the License.
 #
 
+from alembic import op
+
 """Drop embrane plugin table
 
 Revision ID: 1b294093239c
@@ -23,8 +25,6 @@ Create Date: 2015-10-09 14:07:59.968597
 revision = '1b294093239c'
 down_revision = '4af11ca47297'
 
-from alembic import op
-
 
 def upgrade():
     op.drop_table('embrane_pool_port')
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/2b4c2465d44b_dvr_sheduling_refactoring.py b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/2b4c2465d44b_dvr_sheduling_refactoring.py
index 0093bf9157a..a99c567e843 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/2b4c2465d44b_dvr_sheduling_refactoring.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/2b4c2465d44b_dvr_sheduling_refactoring.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """DVR sheduling refactoring
 
 Revision ID: 2b4c2465d44b
@@ -25,9 +28,6 @@ Create Date: 2015-12-23 07:39:49.062767
 revision = '2b4c2465d44b'
 down_revision = '8a6d8bdae39'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 ROUTER_ATTR_TABLE = 'router_extra_attributes'
 ROUTER_BINDING_TABLE = 'routerl3agentbindings'
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/4ffceebfcdc_standard_desc.py b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/4ffceebfcdc_standard_desc.py
index 43a0c06976f..e6e693cf18a 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/4ffceebfcdc_standard_desc.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/4ffceebfcdc_standard_desc.py
@@ -13,6 +13,11 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
+from neutron.db import migration
+
 """standard_desc
 
 Revision ID: 4ffceebfcdc
@@ -21,12 +26,6 @@ Create Date: 2016-02-10 23:12:04.012457
 
 """
 
-from alembic import op
-import sqlalchemy as sa
-
-from neutron.db import migration
-
-
 # revision identifiers, used by Alembic.
 revision = '4ffceebfcdc'
 down_revision = '5ffceebfada'
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/5ffceebfada_rbac_network_external.py b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/5ffceebfada_rbac_network_external.py
index 5b037e269c3..ee060623f95 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/5ffceebfada_rbac_network_external.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/5ffceebfada_rbac_network_external.py
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+from oslo_utils import uuidutils
+import sqlalchemy as sa
+
 """network_rbac_external
 
 Revision ID: 5ffceebfada
@@ -26,10 +30,6 @@ revision = '5ffceebfada'
 down_revision = 'c6c112992c9'
 depends_on = ()
 
-from alembic import op
-from oslo_utils import uuidutils
-import sqlalchemy as sa
-
 
 # A simple model of the external network table with only the fields needed for
 # the migration.
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/8a6d8bdae39_migrate_neutron_resources_table.py b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/8a6d8bdae39_migrate_neutron_resources_table.py
index 38e4bc48857..b42d669cc8f 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/8a6d8bdae39_migrate_neutron_resources_table.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/8a6d8bdae39_migrate_neutron_resources_table.py
@@ -12,6 +12,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """standardattributes migration
 
 Revision ID: 8a6d8bdae39
@@ -25,9 +28,6 @@ revision = '8a6d8bdae39'
 down_revision = '1b294093239c'
 depends_on = ('32e5974ada25',)
 
-from alembic import op
-import sqlalchemy as sa
-
 
 # basic model of the tables with required field for migration
 TABLES = ('ports', 'networks', 'subnets', 'subnetpools', 'securitygroups',
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/c6c112992c9_rbac_qos_policy.py b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/c6c112992c9_rbac_qos_policy.py
index 92624a3cbb3..81053c6c0f8 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/c6c112992c9_rbac_qos_policy.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/c6c112992c9_rbac_qos_policy.py
@@ -13,6 +13,12 @@
 #    under the License.
 #
 
+from alembic import op
+from oslo_utils import uuidutils
+import sqlalchemy as sa
+
+from neutron.db import rbac_db_models
+
 """rbac_qos_policy
 
 Revision ID: c6c112992c9
@@ -21,12 +27,6 @@ Create Date: 2015-11-25 18:45:03.831359
 
 """
 
-from alembic import op
-from oslo_utils import uuidutils
-import sqlalchemy as sa
-
-from neutron.db import rbac_db_models
-
 # revision identifiers, used by Alembic.
 
 revision = 'c6c112992c9'
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/e3278ee65050_drop_nec_plugin_tables.py b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/e3278ee65050_drop_nec_plugin_tables.py
index ca1c135124a..ea5b5c0bbd5 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/contract/e3278ee65050_drop_nec_plugin_tables.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/contract/e3278ee65050_drop_nec_plugin_tables.py
@@ -13,6 +13,8 @@
 #    under the License.
 #
 
+from alembic import op
+
 """Drop NEC plugin tables
 
 Revision ID: e3278ee65050
@@ -25,8 +27,6 @@ Create Date: 2016-02-15 18:50:56.870043
 revision = 'e3278ee65050'
 down_revision = '2b4c2465d44b'
 
-from alembic import op
-
 
 def upgrade():
     op.drop_table('ofcnetworkmappings')
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/0e66c5227a8a_add_desc_to_standard_attr.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/0e66c5227a8a_add_desc_to_standard_attr.py
index 6a881202690..c4b5be73c03 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/0e66c5227a8a_add_desc_to_standard_attr.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/0e66c5227a8a_add_desc_to_standard_attr.py
@@ -13,6 +13,11 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
+from neutron.db import migration
+
 """Add desc to standard attr table
 
 Revision ID: 0e66c5227a8a
@@ -21,12 +26,6 @@ Create Date: 2016-02-02 10:50:34.238563
 
 """
 
-from alembic import op
-import sqlalchemy as sa
-
-from neutron.db import migration
-
-
 # revision identifiers, used by Alembic.
 revision = '0e66c5227a8a'
 down_revision = '3894bccad37f'
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/13cfb89f881a_add_is_default_to_subnetpool.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/13cfb89f881a_add_is_default_to_subnetpool.py
index 48c198e4114..941ba323d48 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/13cfb89f881a_add_is_default_to_subnetpool.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/13cfb89f881a_add_is_default_to_subnetpool.py
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy import sql
+
 """add is_default to subnetpool
 
 Revision ID: 13cfb89f881a
@@ -25,10 +29,6 @@ Create Date: 2015-09-30 15:58:31.170153
 revision = '13cfb89f881a'
 down_revision = '59cb5b6cf4d'
 
-from alembic import op
-import sqlalchemy as sa
-from sqlalchemy import sql
-
 
 def upgrade():
     op.add_column('subnetpools',
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/15be73214821_add_bgp_model_data.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/15be73214821_add_bgp_model_data.py
index 3525731e88a..eedd9db6ae1 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/15be73214821_add_bgp_model_data.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/15be73214821_add_bgp_model_data.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """add dynamic routing model data
 
 Revision ID: 15be73214821
@@ -24,9 +27,6 @@ Create Date: 2015-07-29 13:16:08.604175
 revision = '15be73214821'
 down_revision = '19f26505c74f'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
 
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/15e43b934f81_rbac_qos_policy.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/15e43b934f81_rbac_qos_policy.py
index 5f5052c573e..e213bc55c9c 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/15e43b934f81_rbac_qos_policy.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/15e43b934f81_rbac_qos_policy.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """rbac_qos_policy
 
 Revision ID: 15e43b934f81
@@ -21,9 +24,6 @@ Create Date: 2015-11-25 18:45:03.819115
 
 """
 
-from alembic import op
-import sqlalchemy as sa
-
 # revision identifiers, used by Alembic.
 revision = '15e43b934f81'
 down_revision = 'b4caf27aae4'
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/19f26505c74f_auto_allocated_topology.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/19f26505c74f_auto_allocated_topology.py
index 3fb9635e9f7..d9b056c8ef7 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/19f26505c74f_auto_allocated_topology.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/19f26505c74f_auto_allocated_topology.py
@@ -14,6 +14,10 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy import sql
+
 """ Auto Allocated Topology - aka Get-Me-A-Network
 
 Revision ID: 19f26505c74f
@@ -22,10 +26,6 @@ Create Date: 2015-11-20 11:27:53.419742
 
 """
 
-from alembic import op
-import sqlalchemy as sa
-from sqlalchemy import sql
-
 # revision identifiers, used by Alembic.
 revision = '19f26505c74f'
 down_revision = '1df244e556f5'
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/1df244e556f5_add_unique_ha_router_agent_port_bindings.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/1df244e556f5_add_unique_ha_router_agent_port_bindings.py
index c636fcfa4de..1fe3ee6b4e0 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/1df244e556f5_add_unique_ha_router_agent_port_bindings.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/1df244e556f5_add_unique_ha_router_agent_port_bindings.py
@@ -13,6 +13,12 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib import exceptions
+import sqlalchemy as sa
+
+from neutron._i18n import _
+
 """add_unique_ha_router_agent_port_bindings
 
 Revision ID: 1df244e556f5
@@ -25,12 +31,6 @@ Create Date: 2015-10-02 18:06:01.696742
 revision = '1df244e556f5'
 down_revision = '659bf3d90664'
 
-from alembic import op
-from neutron_lib import exceptions
-import sqlalchemy as sa
-
-from neutron._i18n import _
-
 
 UNIQUE_NAME = 'uniq_ha_router_agent_port_bindings0port_id0l3_agent_id'
 TABLE_NAME = 'ha_router_agent_port_bindings'
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/2f9e956e7532_tag_support.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/2f9e956e7532_tag_support.py
index 820c621984b..8e40172897a 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/2f9e956e7532_tag_support.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/2f9e956e7532_tag_support.py
@@ -12,6 +12,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """tag support
 
 Revision ID: 2f9e956e7532
@@ -24,9 +27,6 @@ Create Date: 2016-01-21 08:11:49.604182
 revision = '2f9e956e7532'
 down_revision = '31ed664953e6'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table(
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/31ed664953e6_add_resource_versions_row_to_agent_table.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/31ed664953e6_add_resource_versions_row_to_agent_table.py
index 1463948d999..6be75432d0f 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/31ed664953e6_add_resource_versions_row_to_agent_table.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/31ed664953e6_add_resource_versions_row_to_agent_table.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add resource_versions row to agent table
 
 Revision ID: 31ed664953e6
@@ -25,9 +28,6 @@ Create Date: 2016-01-15 13:41:30.016915
 revision = '31ed664953e6'
 down_revision = '15e43b934f81'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column('agents',
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/32e5974ada25_add_neutron_resources_table.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/32e5974ada25_add_neutron_resources_table.py
index 39e21048d10..bc4851c3abb 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/32e5974ada25_add_neutron_resources_table.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/32e5974ada25_add_neutron_resources_table.py
@@ -12,6 +12,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add standard attribute table
 
 Revision ID: 32e5974ada25
@@ -24,9 +27,6 @@ Create Date: 2015-09-10 00:22:47.618593
 revision = '32e5974ada25'
 down_revision = '13cfb89f881a'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 TABLES = ('ports', 'networks', 'subnets', 'subnetpools', 'securitygroups',
           'floatingips', 'routers', 'securitygrouprules')
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/3894bccad37f_add_timestamp_to_base_resources.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/3894bccad37f_add_timestamp_to_base_resources.py
index ca52ba03f5f..7ff8fbbf070 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/3894bccad37f_add_timestamp_to_base_resources.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/3894bccad37f_add_timestamp_to_base_resources.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """add_timestamp_to_base_resources
 
 Revision ID: 3894bccad37f
@@ -25,9 +28,6 @@ Create Date: 2016-03-01 04:19:58.852612
 revision = '3894bccad37f'
 down_revision = '2f9e956e7532'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     for column_name in ['created_at', 'updated_at']:
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/59cb5b6cf4d_availability_zone.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/59cb5b6cf4d_availability_zone.py
index d2c5482db4c..faf531b0e4e 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/59cb5b6cf4d_availability_zone.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/59cb5b6cf4d_availability_zone.py
@@ -12,6 +12,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add availability zone
 
 Revision ID: 59cb5b6cf4d
@@ -24,9 +27,6 @@ Create Date: 2015-01-20 14:38:47.156574
 revision = '59cb5b6cf4d'
 down_revision = '34af2b5c5a59'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column('agents',
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/659bf3d90664_add_attributes_to_support_external_dns_integration.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/659bf3d90664_add_attributes_to_support_external_dns_integration.py
index 488993593fb..8565fbc4947 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/659bf3d90664_add_attributes_to_support_external_dns_integration.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/659bf3d90664_add_attributes_to_support_external_dns_integration.py
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib.db import constants
+import sqlalchemy as sa
+
 """Add tables and attributes to support external DNS integration
 
 Revision ID: 659bf3d90664
@@ -25,10 +29,6 @@ Create Date: 2015-09-11 00:22:47.618593
 revision = '659bf3d90664'
 down_revision = 'c3a73f615e4'
 
-from alembic import op
-from neutron_lib.db import constants
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table('networkdnsdomains',
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/b4caf27aae4_add_bgp_dragent_model_data.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/b4caf27aae4_add_bgp_dragent_model_data.py
index 0959b52140f..d57901642ed 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/b4caf27aae4_add_bgp_dragent_model_data.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/b4caf27aae4_add_bgp_dragent_model_data.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """add_bgp_dragent_model_data
 
 Revision ID: b4caf27aae4
@@ -25,9 +28,6 @@ Create Date: 2015-08-20 17:05:31.038704
 revision = 'b4caf27aae4'
 down_revision = '15be73214821'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
 
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/c3a73f615e4_add_ip_version_to_address_scope.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/c3a73f615e4_add_ip_version_to_address_scope.py
index e039f700cbf..0f2df570cc7 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/c3a73f615e4_add_ip_version_to_address_scope.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/c3a73f615e4_add_ip_version_to_address_scope.py
@@ -12,6 +12,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add ip_version to AddressScope
 
 Revision ID: c3a73f615e4
@@ -24,9 +27,6 @@ Create Date: 2015-10-08 17:34:32.231256
 revision = 'c3a73f615e4'
 down_revision = 'dce3ec7a25c9'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column('address_scopes',
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/dce3ec7a25c9_router_az.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/dce3ec7a25c9_router_az.py
index 62af98a0644..50624eb6ff4 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/dce3ec7a25c9_router_az.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/dce3ec7a25c9_router_az.py
@@ -12,6 +12,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add router availability zone
 
 Revision ID: dce3ec7a25c9
@@ -24,9 +27,6 @@ Create Date: 2015-09-17 09:36:17.468901
 revision = 'dce3ec7a25c9'
 down_revision = 'ec7fcfbf72ee'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column('router_extra_attributes',
diff --git a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/ec7fcfbf72ee_network_az.py b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/ec7fcfbf72ee_network_az.py
index e6582d4cd1b..d060440dae7 100644
--- a/neutron/db/migration/alembic_migrations/versions/mitaka/expand/ec7fcfbf72ee_network_az.py
+++ b/neutron/db/migration/alembic_migrations/versions/mitaka/expand/ec7fcfbf72ee_network_az.py
@@ -12,6 +12,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add network availability zone
 
 Revision ID: ec7fcfbf72ee
@@ -24,9 +27,6 @@ Create Date: 2015-09-17 09:21:51.257579
 revision = 'ec7fcfbf72ee'
 down_revision = '32e5974ada25'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column('networks',
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/2e0d7a8a1586_add_binding_index_to_routerl3agentbinding.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/2e0d7a8a1586_add_binding_index_to_routerl3agentbinding.py
index 16961cd2430..2fb6fb644f3 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/2e0d7a8a1586_add_binding_index_to_routerl3agentbinding.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/2e0d7a8a1586_add_binding_index_to_routerl3agentbinding.py
@@ -13,6 +13,11 @@
 #    under the License.
 #
 
+from collections import defaultdict
+
+from alembic import op
+import sqlalchemy as sa
+
 """Add binding index to RouterL3AgentBinding
 
 Revision ID: 2e0d7a8a1586
@@ -25,11 +30,6 @@ Create Date: 2016-09-01 14:01:57.263289
 revision = '2e0d7a8a1586'
 down_revision = '97c25b0d2353'
 
-from collections import defaultdict
-
-from alembic import op
-import sqlalchemy as sa
-
 
 ROUTER_L3_AGENT_BINDING = 'routerl3agentbindings'
 
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/3b935b28e7a0_migrate_to_pluggable_ipam.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/3b935b28e7a0_migrate_to_pluggable_ipam.py
index 512d3acd402..03dd64b4a1e 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/3b935b28e7a0_migrate_to_pluggable_ipam.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/3b935b28e7a0_migrate_to_pluggable_ipam.py
@@ -13,17 +13,18 @@
 #    under the License.
 #
 
+from alembic import op
+from oslo_utils import uuidutils
+import sqlalchemy as sa
+
+from neutron.common import constants as const
+
 """migrate to pluggable ipam """
 
 # revision identifiers, used by Alembic.
 revision = '3b935b28e7a0'
 down_revision = 'a8b517cff8ab'
 
-from alembic import op
-from oslo_utils import uuidutils
-import sqlalchemy as sa
-
-from neutron.common import constants as const
 
 # A simple models for tables with only the fields needed for the migration.
 neutron_subnet = sa.Table('subnets', sa.MetaData(),
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/4bcd4df1f426_rename_ml2_dvr_port_bindings.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/4bcd4df1f426_rename_ml2_dvr_port_bindings.py
index 7e46588a537..97fc6241358 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/4bcd4df1f426_rename_ml2_dvr_port_bindings.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/4bcd4df1f426_rename_ml2_dvr_port_bindings.py
@@ -13,6 +13,8 @@
 #    under the License.
 #
 
+from alembic import op
+
 """Rename ml2_dvr_port_bindings
 
 Revision ID: 4bcd4df1f426
@@ -25,8 +27,6 @@ Create Date: 2016-06-02 14:06:04.112998
 revision = '4bcd4df1f426'
 down_revision = '8fd3918ef6f4'
 
-from alembic import op
-
 
 OLD_REFERRED_TABLE_NAME = 'ml2_dvr_port_bindings'
 NEW_REFERRED_TABLE_NAME = 'ml2_distributed_port_bindings'
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/5c85685d616d_remove_availability_ranges.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/5c85685d616d_remove_availability_ranges.py
index 9f8c1a492c1..e47f1c128c9 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/5c85685d616d_remove_availability_ranges.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/5c85685d616d_remove_availability_ranges.py
@@ -11,12 +11,12 @@
 #    under the License.
 #
 
-"""Remove availability ranges."""
-
 from alembic import op
 
 from neutron.db import migration
 
+"""Remove availability ranges."""
+
 
 revision = '5c85685d616d'
 down_revision = '2e0d7a8a1586'
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/7bbb25278f53_device_owner_ha_replicate_int.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/7bbb25278f53_device_owner_ha_replicate_int.py
index 0b35706c7af..09a8ceed739 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/7bbb25278f53_device_owner_ha_replicate_int.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/7bbb25278f53_device_owner_ha_replicate_int.py
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib import constants
+import sqlalchemy as sa
+
 """device_owner_ha_replicate_int
 
 Revision ID: 7bbb25278f53
@@ -25,10 +29,6 @@ Create Date: 2016-03-22 10:00:43.245503
 revision = '7bbb25278f53'
 down_revision = '4ffceebfcdc'
 
-from alembic import op
-from neutron_lib import constants
-import sqlalchemy as sa
-
 
 ROUTER_ATTR_TABLE = 'router_extra_attributes'
 ROUTER_PORTS_TABLE = 'routerports'
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/7d9d8eeec6ad_rename_tenant_to_project.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/7d9d8eeec6ad_rename_tenant_to_project.py
index 298fa25be99..c6f7bd6f0e9 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/7d9d8eeec6ad_rename_tenant_to_project.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/7d9d8eeec6ad_rename_tenant_to_project.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """rename tenant to project
 
 Revision ID: 7d9d8eeec6ad
@@ -25,9 +28,6 @@ revision = '7d9d8eeec6ad'
 down_revision = 'a84ccf28f06a'
 depends_on = ('5abc0278ca73',)
 
-from alembic import op
-import sqlalchemy as sa
-
 
 _INSPECTOR = None
 
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/89ab9a816d70_rename_ml2_network_segments.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/89ab9a816d70_rename_ml2_network_segments.py
index cb82d656b23..e7c0d3c3168 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/89ab9a816d70_rename_ml2_network_segments.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/89ab9a816d70_rename_ml2_network_segments.py
@@ -10,6 +10,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from alembic import op
+from sqlalchemy.engine import reflection
+
 """Rename ml2_network_segments table
 
 Revision ID: 89ab9a816d70
@@ -22,9 +25,6 @@ Create Date: 2016-03-22 00:22:47.618593
 revision = '89ab9a816d70'
 down_revision = '7bbb25278f53'
 
-from alembic import op
-from sqlalchemy.engine import reflection
-
 
 TABLE_NAME = 'ml2_port_binding_levels'
 OLD_REFERRED_TABLE_NAME = 'ml2_network_segments'
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/8fd3918ef6f4_add_segment_host_mapping.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/8fd3918ef6f4_add_segment_host_mapping.py
index f0c28a2afa8..9b61f4062fe 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/8fd3918ef6f4_add_segment_host_mapping.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/8fd3918ef6f4_add_segment_host_mapping.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add segment_host_mapping table.
 
 Revision ID: 8fd3918ef6f4
@@ -25,9 +28,6 @@ Create Date: 2016-02-25 00:22:47.618593
 revision = '8fd3918ef6f4'
 down_revision = 'c879c5e1ee90'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table('segmenthostmappings',
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/97c25b0d2353_add_name_desc.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/97c25b0d2353_add_name_desc.py
index adf0a491430..bbaf5741d43 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/97c25b0d2353_add_name_desc.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/97c25b0d2353_add_name_desc.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add Name and Description to the networksegments table """
 
 # revision identifiers, used by Alembic.
@@ -27,9 +30,6 @@ depends_on = ('89ab9a816d70',)
 # refer <https://docs.openstack.org/neutron/latest/contributor/
 # alembic_migrations.html#expand-and-contract-scripts>
 
-from alembic import op
-import sqlalchemy as sa
-
 TBL = 'networksegments'
 
 TBL_MODEL = sa.Table(TBL, sa.MetaData(),
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/a84ccf28f06a_migrate_dns_name_from_port.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/a84ccf28f06a_migrate_dns_name_from_port.py
index df6adf4e0e5..4fddbff869c 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/a84ccf28f06a_migrate_dns_name_from_port.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/a84ccf28f06a_migrate_dns_name_from_port.py
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib.db import constants
+import sqlalchemy as sa
+
 """migrate dns name from port"""
 
 # revision identifiers, used by Alembic.
@@ -20,10 +24,6 @@ revision = 'a84ccf28f06a'
 down_revision = 'b67e765a3524'
 depends_on = ('a963b38d82f4',)
 
-from alembic import op
-from neutron_lib.db import constants
-import sqlalchemy as sa
-
 
 ports = sa.Table(
     'ports', sa.MetaData(),
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/a8b517cff8ab_add_routerport_bindings_for_ha.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/a8b517cff8ab_add_routerport_bindings_for_ha.py
index eed0fdfb623..ec9e805fc20 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/a8b517cff8ab_add_routerport_bindings_for_ha.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/a8b517cff8ab_add_routerport_bindings_for_ha.py
@@ -10,6 +10,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from alembic import op
+from neutron_lib import constants as lib_const
+import sqlalchemy as sa
+
+from neutron.common import constants
+
 """Add routerport bindings for L3 HA
 
 Revision ID: a8b517cff8ab
@@ -22,12 +28,6 @@ Create Date: 2016-07-18 14:31:45.725516
 revision = 'a8b517cff8ab'
 down_revision = '7d9d8eeec6ad'
 
-from alembic import op
-from neutron_lib import constants as lib_const
-import sqlalchemy as sa
-
-from neutron.common import constants
-
 
 HA_AGENT_BINDINGS = 'ha_router_agent_port_bindings'
 ROUTER_PORTS = 'routerports'
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/b12a3ef66e62_add_standardattr_to_qos_policies.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/b12a3ef66e62_add_standardattr_to_qos_policies.py
index 5af5995459c..3c01c1fde86 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/b12a3ef66e62_add_standardattr_to_qos_policies.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/b12a3ef66e62_add_standardattr_to_qos_policies.py
@@ -12,6 +12,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """add standardattr to qos policies
 
 Revision ID: b12a3ef66e62
@@ -25,9 +28,6 @@ revision = 'b12a3ef66e62'
 down_revision = '3b935b28e7a0'
 depends_on = ('67daae611b6e',)
 
-from alembic import op
-import sqlalchemy as sa
-
 
 # basic model of the tables with required field for migration
 TABLE = 'qos_policies'
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/b67e765a3524_remove_mtu_column_from_networks.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/b67e765a3524_remove_mtu_column_from_networks.py
index 9948f4a3529..64b87b23567 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/b67e765a3524_remove_mtu_column_from_networks.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/b67e765a3524_remove_mtu_column_from_networks.py
@@ -11,6 +11,8 @@
 #    under the License.
 #
 
+from alembic import op
+
 """Remove mtu column from networks.
 
 Revision ID: b67e765a3524
@@ -23,8 +25,6 @@ Create Date: 2016-07-17 02:07:36.625196
 revision = 'b67e765a3524'
 down_revision = '4bcd4df1f426'
 
-from alembic import op
-
 
 def upgrade():
     op.drop_column('networks', 'mtu')
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/contract/c879c5e1ee90_add_segment_id_to_subnet.py b/neutron/db/migration/alembic_migrations/versions/newton/contract/c879c5e1ee90_add_segment_id_to_subnet.py
index 03e57d85640..aac93c0f5be 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/contract/c879c5e1ee90_add_segment_id_to_subnet.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/contract/c879c5e1ee90_add_segment_id_to_subnet.py
@@ -13,15 +13,15 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add segment_id to subnet """
 
 # revision identifiers, used by Alembic.
 revision = 'c879c5e1ee90'
 down_revision = '89ab9a816d70'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column('subnets',
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/030a959ceafa_uniq_routerports0port_id.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/030a959ceafa_uniq_routerports0port_id.py
index c6751db6ff1..427abfe28c6 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/030a959ceafa_uniq_routerports0port_id.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/030a959ceafa_uniq_routerports0port_id.py
@@ -13,6 +13,12 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib import exceptions
+import sqlalchemy as sa
+
+from neutron._i18n import _
+
 """uniq_routerports0port_id
 
 Revision ID: 030a959ceafa
@@ -25,12 +31,6 @@ Create Date: 2016-06-21 11:33:13.043879
 revision = '030a959ceafa'
 down_revision = '3d0e74aa7d37'
 
-from alembic import op
-from neutron_lib import exceptions
-import sqlalchemy as sa
-
-from neutron._i18n import _
-
 routerports = sa.Table(
     'routerports', sa.MetaData(),
     sa.Column('router_id', sa.String(36)),
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/0f5bef0f87d4_add_qos_minimum_bandwidth_rules.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/0f5bef0f87d4_add_qos_minimum_bandwidth_rules.py
index 452b92900ed..d00d84da129 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/0f5bef0f87d4_add_qos_minimum_bandwidth_rules.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/0f5bef0f87d4_add_qos_minimum_bandwidth_rules.py
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib import constants
+import sqlalchemy as sa
+
 """add_qos_minimum_bandwidth_rules
 
 Revision ID: 0f5bef0f87d4
@@ -25,10 +29,6 @@ Create Date: 2016-07-29 14:33:37.243487
 revision = '0f5bef0f87d4'
 down_revision = 'a5648cfeeadf'
 
-from alembic import op
-from neutron_lib import constants
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table(
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/30107ab6a3ee_provisioning_blocks.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/30107ab6a3ee_provisioning_blocks.py
index 01d56f39f6c..e09a4fd59e9 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/30107ab6a3ee_provisioning_blocks.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/30107ab6a3ee_provisioning_blocks.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """provisioning_blocks.py
 
 Revision ID: 30107ab6a3ee
@@ -24,8 +27,6 @@ Create Date: 2016-04-15 05:59:59.000001
 # revision identifiers, used by Alembic.
 revision = '30107ab6a3ee'
 down_revision = 'd3435b514502'
-from alembic import op
-import sqlalchemy as sa
 
 
 def upgrade():
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/3d0e74aa7d37_add_flavor_id_to_routers.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/3d0e74aa7d37_add_flavor_id_to_routers.py
index 8b48d23b99c..9f7f4c149ae 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/3d0e74aa7d37_add_flavor_id_to_routers.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/3d0e74aa7d37_add_flavor_id_to_routers.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add flavor_id to Router
 
 Revision ID: 3d0e74aa7d37
@@ -21,10 +24,6 @@ Create Date: 2016-05-05 00:22:47.618593
 
 """
 
-from alembic import op
-import sqlalchemy as sa
-
-
 # revision identifiers, used by Alembic.
 revision = '3d0e74aa7d37'
 down_revision = 'a963b38d82f4'
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/45f8dd33480b_qos_dscp_db_addition.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/45f8dd33480b_qos_dscp_db_addition.py
index 48f2217efa3..9efddf51d23 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/45f8dd33480b_qos_dscp_db_addition.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/45f8dd33480b_qos_dscp_db_addition.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """qos dscp db addition
 
 Revision ID: 45f8dd33480b
@@ -25,9 +28,6 @@ Create Date: 2015-12-03 07:16:24.742290
 revision = '45f8dd33480b'
 down_revision = '0e66c5227a8a'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
 
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/5abc0278ca73_add_support_for_vlan_trunking.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/5abc0278ca73_add_support_for_vlan_trunking.py
index cff6a845ce1..76fe4b4a09b 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/5abc0278ca73_add_support_for_vlan_trunking.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/5abc0278ca73_add_support_for_vlan_trunking.py
@@ -11,15 +11,15 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy import sql
+
 """Add support for VLAN trunking"""
 
 revision = '5abc0278ca73'
 down_revision = '45f8dd33480b'
 
-from alembic import op
-import sqlalchemy as sa
-from sqlalchemy import sql
-
 
 def upgrade():
     op.create_table('trunks',
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/5cd92597d11d_add_ip_allocation_to_port.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/5cd92597d11d_add_ip_allocation_to_port.py
index e265cd54422..58cad34cb7e 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/5cd92597d11d_add_ip_allocation_to_port.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/5cd92597d11d_add_ip_allocation_to_port.py
@@ -11,18 +11,18 @@
 #    under the License.
 #
 
-"""Add ip_allocation to port """
-
 from alembic import op
 import sqlalchemy as sa
 
 from neutron.db import migration
 
+"""Add ip_allocation to port """
 
 # revision identifiers, used by Alembic.
 revision = '5cd92597d11d'
 down_revision = '6b461a21bcfc'
 
+
 # milestone identifier, used by neutron-db-manage
 neutron_milestone = [migration.NEWTON]
 
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/67daae611b6e_add_standard_attr_to_qos_policies.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/67daae611b6e_add_standard_attr_to_qos_policies.py
index cbfc0db5523..64cc039b023 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/67daae611b6e_add_standard_attr_to_qos_policies.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/67daae611b6e_add_standard_attr_to_qos_policies.py
@@ -12,6 +12,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """add standardattr to qos policies
 
 Revision ID: 67daae611b6e
@@ -23,9 +26,6 @@ Create Date: 2016-08-18 14:10:30.021015
 revision = '67daae611b6e'
 down_revision = '0f5bef0f87d4'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 TABLE = 'qos_policies'
 
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/6b461a21bcfc_uniq_floatingips0floating_network_.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/6b461a21bcfc_uniq_floatingips0floating_network_.py
index 8d674cd2c38..e9990b23870 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/6b461a21bcfc_uniq_floatingips0floating_network_.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/6b461a21bcfc_uniq_floatingips0floating_network_.py
@@ -13,6 +13,12 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib import exceptions
+import sqlalchemy as sa
+
+from neutron._i18n import _
+
 """uniq_floatingips0floating_network_id0fixed_port_id0fixed_ip_addr
 
 Revision ID: 6b461a21bcfc
@@ -25,12 +31,6 @@ Create Date: 2016-06-03 16:00:38.273324
 revision = '6b461a21bcfc'
 down_revision = '67daae611b6e'
 
-from alembic import op
-from neutron_lib import exceptions
-import sqlalchemy as sa
-
-from neutron._i18n import _
-
 
 floatingips = sa.Table(
     'floatingips', sa.MetaData(),
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/a5648cfeeadf_add_subnet_service_types.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/a5648cfeeadf_add_subnet_service_types.py
index bcbfd87a72f..62b18450bfd 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/a5648cfeeadf_add_subnet_service_types.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/a5648cfeeadf_add_subnet_service_types.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add support for Subnet Service Types
 
 Revision ID: a5648cfeeadf
@@ -25,9 +28,6 @@ Create Date: 2016-03-15 18:00:00.190173
 revision = 'a5648cfeeadf'
 down_revision = '030a959ceafa'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table('subnet_service_types',
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/a963b38d82f4_add_dns_name_to_portdnses.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/a963b38d82f4_add_dns_name_to_portdnses.py
index 3984e73b772..c37e95acbca 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/a963b38d82f4_add_dns_name_to_portdnses.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/a963b38d82f4_add_dns_name_to_portdnses.py
@@ -13,15 +13,15 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """add dns name to portdnses"""
 
 # revision identifiers, used by Alembic.
 revision = 'a963b38d82f4'
 down_revision = 'c415aab1c048'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column('portdnses',
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/c415aab1c048_add_revisions_column.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/c415aab1c048_add_revisions_column.py
index f94be8e9945..0ecc28db416 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/c415aab1c048_add_revisions_column.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/c415aab1c048_add_revisions_column.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """add revisions table
 
 Revision ID: c415aab1c048
@@ -24,9 +27,6 @@ Create Date: 2016-04-11 03:16:24.742290
 revision = 'c415aab1c048'
 down_revision = '30107ab6a3ee'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column(
diff --git a/neutron/db/migration/alembic_migrations/versions/newton/expand/d3435b514502_add_device_id_index_to_port.py b/neutron/db/migration/alembic_migrations/versions/newton/expand/d3435b514502_add_device_id_index_to_port.py
index d55748e42a0..4ff99f10d14 100644
--- a/neutron/db/migration/alembic_migrations/versions/newton/expand/d3435b514502_add_device_id_index_to_port.py
+++ b/neutron/db/migration/alembic_migrations/versions/newton/expand/d3435b514502_add_device_id_index_to_port.py
@@ -13,6 +13,8 @@
 #    under the License.
 #
 
+from alembic import op
+
 """Add device_id index to Port
 
 Revision ID: d3435b514502
@@ -25,8 +27,6 @@ Create Date: 2016-04-25 22:13:16.676761
 revision = 'd3435b514502'
 down_revision = '5abc0278ca73'
 
-from alembic import op
-
 
 def upgrade():
     op.create_index('ix_ports_device_id', 'ports', ['device_id'], unique=False)
diff --git a/neutron/db/migration/alembic_migrations/versions/ocata/expand/929c968efe70_add_pk_version_table.py b/neutron/db/migration/alembic_migrations/versions/ocata/expand/929c968efe70_add_pk_version_table.py
index adf943b995c..b3c65f6d190 100644
--- a/neutron/db/migration/alembic_migrations/versions/ocata/expand/929c968efe70_add_pk_version_table.py
+++ b/neutron/db/migration/alembic_migrations/versions/ocata/expand/929c968efe70_add_pk_version_table.py
@@ -13,6 +13,8 @@
 #    under the License.
 #
 
+from neutron.db import migration
+
 """add_pk_version_table
 
 Revision ID: 929c968efe70
@@ -26,8 +28,5 @@ revision = '929c968efe70'
 down_revision = '5cd92597d11d'
 
 
-from neutron.db import migration
-
-
 def upgrade():
     migration.pk_on_alembic_version_table()
diff --git a/neutron/db/migration/alembic_migrations/versions/ocata/expand/a9c43481023c_extend_ml2_port_bindings.py b/neutron/db/migration/alembic_migrations/versions/ocata/expand/a9c43481023c_extend_ml2_port_bindings.py
index 887fe763080..5cbe6e28285 100644
--- a/neutron/db/migration/alembic_migrations/versions/ocata/expand/a9c43481023c_extend_ml2_port_bindings.py
+++ b/neutron/db/migration/alembic_migrations/versions/ocata/expand/a9c43481023c_extend_ml2_port_bindings.py
@@ -13,6 +13,13 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib import constants
+import sqlalchemy as sa
+from sqlalchemy.engine.reflection import Inspector as insp
+
+from neutron.db import migration
+
 """extend_pk_with_host_and_add_status_to_ml2_port_binding
 
 Revision ID: a9c43481023c
@@ -25,13 +32,6 @@ Create Date: 2016-11-22 11:48:43.479552
 revision = 'a9c43481023c'
 down_revision = '929c968efe70'
 
-from alembic import op
-from neutron_lib import constants
-import sqlalchemy as sa
-from sqlalchemy.engine.reflection import Inspector as insp
-
-from neutron.db import migration
-
 MYSQL_ENGINE = 'mysql'
 ML2_PORT_BINDING = 'ml2_port_bindings'
 neutron_milestone = [migration.OCATA]
diff --git a/neutron/db/migration/alembic_migrations/versions/pike/expand/2b42d90729da_qos_add_direction_to_bw_limit_rule_table.py b/neutron/db/migration/alembic_migrations/versions/pike/expand/2b42d90729da_qos_add_direction_to_bw_limit_rule_table.py
index 16850e1177c..bcbb1edc59c 100644
--- a/neutron/db/migration/alembic_migrations/versions/pike/expand/2b42d90729da_qos_add_direction_to_bw_limit_rule_table.py
+++ b/neutron/db/migration/alembic_migrations/versions/pike/expand/2b42d90729da_qos_add_direction_to_bw_limit_rule_table.py
@@ -13,6 +13,12 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib import constants
+import sqlalchemy as sa
+
+from neutron.db import migration
+
 """qos add direction to bw_limit_rule table
 
 Revision ID: 2b42d90729da
@@ -25,12 +31,6 @@ Create Date: 2017-04-03 20:56:00.169599
 revision = '2b42d90729da'
 down_revision = '804a3c76314c'
 
-from alembic import op
-from neutron_lib import constants
-import sqlalchemy as sa
-
-from neutron.db import migration
-
 
 policies_table_name = "qos_policies"
 bw_limit_table_name = "qos_bandwidth_limit_rules"
diff --git a/neutron/db/migration/alembic_migrations/versions/pike/expand/349b6fd605a6_add_dns_domain_to_portdnses.py b/neutron/db/migration/alembic_migrations/versions/pike/expand/349b6fd605a6_add_dns_domain_to_portdnses.py
index 02c7461c28f..ab919d1f06d 100644
--- a/neutron/db/migration/alembic_migrations/versions/pike/expand/349b6fd605a6_add_dns_domain_to_portdnses.py
+++ b/neutron/db/migration/alembic_migrations/versions/pike/expand/349b6fd605a6_add_dns_domain_to_portdnses.py
@@ -13,6 +13,10 @@
 #    under the License.
 #
 
+from alembic import op
+from neutron_lib.db import constants
+import sqlalchemy as sa
+
 """Add dns_domain to portdnses
 
 Revision ID: 349b6fd605a6
@@ -25,10 +29,6 @@ Create Date: 2017-04-15 00:22:47.618593
 revision = '349b6fd605a6'
 down_revision = 'c8c222d42aa9'
 
-from alembic import op
-from neutron_lib.db import constants
-import sqlalchemy as sa
-
 
 def upgrade():
     op.add_column('portdnses',
diff --git a/neutron/db/migration/alembic_migrations/versions/pike/expand/62c781cb6192_add_qos_policies_default_table.py b/neutron/db/migration/alembic_migrations/versions/pike/expand/62c781cb6192_add_qos_policies_default_table.py
index 557ac77da73..65d3500f797 100644
--- a/neutron/db/migration/alembic_migrations/versions/pike/expand/62c781cb6192_add_qos_policies_default_table.py
+++ b/neutron/db/migration/alembic_migrations/versions/pike/expand/62c781cb6192_add_qos_policies_default_table.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """add is default to qos policies
 
 Revision ID: 62c781cb6192
@@ -25,9 +28,6 @@ Create Date: 2017-02-07 13:28:35.894357
 revision = '62c781cb6192'
 down_revision = '2b42d90729da'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table(
diff --git a/neutron/db/migration/alembic_migrations/versions/pike/expand/7d32f979895f_add_mtu_for_networks.py b/neutron/db/migration/alembic_migrations/versions/pike/expand/7d32f979895f_add_mtu_for_networks.py
index 2b468111518..e6076b6b060 100644
--- a/neutron/db/migration/alembic_migrations/versions/pike/expand/7d32f979895f_add_mtu_for_networks.py
+++ b/neutron/db/migration/alembic_migrations/versions/pike/expand/7d32f979895f_add_mtu_for_networks.py
@@ -11,6 +11,11 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
+from neutron.db import migration
+
 """add mtu for networks
 
 Revision ID: 7d32f979895f
@@ -19,12 +24,6 @@ Create Date: 2017-07-13 19:25:29.204547
 
 """
 
-from alembic import op
-import sqlalchemy as sa
-
-from neutron.db import migration
-
-
 # revision identifiers, used by Alembic.
 revision = '7d32f979895f'
 down_revision = '349b6fd605a6'
diff --git a/neutron/db/migration/alembic_migrations/versions/pike/expand/804a3c76314c_add_data_plane_status_to_port.py b/neutron/db/migration/alembic_migrations/versions/pike/expand/804a3c76314c_add_data_plane_status_to_port.py
index bd4d1472b80..0a1804ed757 100644
--- a/neutron/db/migration/alembic_migrations/versions/pike/expand/804a3c76314c_add_data_plane_status_to_port.py
+++ b/neutron/db/migration/alembic_migrations/versions/pike/expand/804a3c76314c_add_data_plane_status_to_port.py
@@ -13,6 +13,9 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
 """Add data_plane_status to Port
 
 Revision ID: 804a3c76314c
@@ -25,9 +28,6 @@ Create Date: 2017-01-17 13:51:45.737987
 revision = '804a3c76314c'
 down_revision = 'a9c43481023c'
 
-from alembic import op
-import sqlalchemy as sa
-
 
 def upgrade():
     op.create_table('portdataplanestatuses',
diff --git a/neutron/db/migration/alembic_migrations/versions/pike/expand/c8c222d42aa9_logging_api.py b/neutron/db/migration/alembic_migrations/versions/pike/expand/c8c222d42aa9_logging_api.py
index 4c41a1fc585..7a6c75c3892 100644
--- a/neutron/db/migration/alembic_migrations/versions/pike/expand/c8c222d42aa9_logging_api.py
+++ b/neutron/db/migration/alembic_migrations/versions/pike/expand/c8c222d42aa9_logging_api.py
@@ -13,6 +13,11 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
+from neutron_lib.db import constants as db_const
+
 """logging api
 
 Revision ID: c8c222d42aa9
@@ -25,11 +30,6 @@ Create Date: 2017-05-30 11:51:08.173604
 revision = 'c8c222d42aa9'
 down_revision = '62c781cb6192'
 
-from alembic import op
-import sqlalchemy as sa
-
-from neutron_lib.db import constants as db_const
-
 
 def upgrade():
 
diff --git a/neutron/db/migration/alembic_migrations/versions/queens/expand/594422d373ee_fip_qos.py b/neutron/db/migration/alembic_migrations/versions/queens/expand/594422d373ee_fip_qos.py
index 65182a47d20..0157a7dd93f 100644
--- a/neutron/db/migration/alembic_migrations/versions/queens/expand/594422d373ee_fip_qos.py
+++ b/neutron/db/migration/alembic_migrations/versions/queens/expand/594422d373ee_fip_qos.py
@@ -12,6 +12,13 @@
 #    under the License.
 #
 
+from alembic import op
+import sqlalchemy as sa
+
+from neutron_lib.db import constants as db_const
+
+from neutron.db import migration
+
 """fip qos
 
 Revision ID: 594422d373ee
@@ -24,13 +31,6 @@ Create Date: 2016-04-26 17:16:10.323756
 revision = '594422d373ee'
 down_revision = '7d32f979895f'
 
-from alembic import op
-import sqlalchemy as sa
-
-from neutron_lib.db import constants as db_const
-
-from neutron.db import migration
-
 # milestone identifier, used by neutron-db-manage
 neutron_milestone = [migration.QUEENS]
 
diff --git a/neutron/db/migration/alembic_migrations/versions/rocky/expand/61663558142c_add_ha_router_state.py b/neutron/db/migration/alembic_migrations/versions/rocky/expand/61663558142c_add_ha_router_state.py
index ce87463f25c..dbf8251a62f 100644
--- a/neutron/db/migration/alembic_migrations/versions/rocky/expand/61663558142c_add_ha_router_state.py
+++ b/neutron/db/migration/alembic_migrations/versions/rocky/expand/61663558142c_add_ha_router_state.py
@@ -12,6 +12,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 #
+
+import sqlalchemy as sa
+
+from neutron.common import constants
+from neutron.db import migration
+
 """Add unknown state to HA router
 
 Revision ID: 61663558142c
@@ -23,11 +29,6 @@ Create Date: 2017-05-18 14:31:45.725516
 revision = '61663558142c'
 down_revision = '594422d373ee'
 
-import sqlalchemy as sa
-
-from neutron.common import constants
-from neutron.db import migration
-
 
 ha_port_bindings_table_name = "ha_router_agent_port_bindings"
 new_enum = sa.Enum(
diff --git a/tox.ini b/tox.ini
index 9e603bba53c..235720aa2cc 100644
--- a/tox.ini
+++ b/tox.ini
@@ -146,9 +146,8 @@ commands = sphinx-build -W -b linkcheck doc/source doc/build/linkcheck
 # N534 Untranslated exception message
 # N536 Use assertIsNone rather than assertEqual to check for None values
 # TODO(amotoki) check the following new rules should be fixed or ignored
-# E402 module level import not at top of file
 # E731 do not assign a lambda expression, use a def
-ignore = E125,E126,E128,E129,E265,E402,E731,H404,H405,N530,N534,N536
+ignore = E125,E126,E128,E129,E265,E731,H404,H405,N530,N534,N536
 # H106: Don't put vim configuration in source files
 # H203: Use assertIs(Not)None to check for None
 # H204: Use assert(Not)Equal to check for equality