diff --git a/os_ken/app/simple_switch_snort.py b/os_ken/app/simple_switch_snort.py
index 5849f3b2..3b792e58 100644
--- a/os_ken/app/simple_switch_snort.py
+++ b/os_ken/app/simple_switch_snort.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import array
 
 from os_ken.base import app_manager
diff --git a/os_ken/cmd/of_config_cli.py b/os_ken/cmd/of_config_cli.py
index da0e2499..3ce256b7 100755
--- a/os_ken/cmd/of_config_cli.py
+++ b/os_ken/cmd/of_config_cli.py
@@ -23,8 +23,6 @@
 #      --peers=sw1=localhost:1830:username:password
 #     (Cmd) raw_get sw1
 
-from __future__ import print_function
-
 import cmd
 import sys
 
diff --git a/os_ken/cmd/rpc_cli.py b/os_ken/cmd/rpc_cli.py
index f21c2fa1..da2d4018 100755
--- a/os_ken/cmd/rpc_cli.py
+++ b/os_ken/cmd/rpc_cli.py
@@ -29,8 +29,6 @@
 #     NOTIFICATION from echo-server ['notify-method', ['param1', 'param2']]
 #     (Cmd)
 
-from __future__ import print_function
-
 import ast
 import cmd
 import signal
diff --git a/os_ken/lib/ovs/vsctl.py b/os_ken/lib/ovs/vsctl.py
index b20dbb1d..99febe17 100644
--- a/os_ken/lib/ovs/vsctl.py
+++ b/os_ken/lib/ovs/vsctl.py
@@ -18,8 +18,6 @@
 ``ovs-vsctl`` command like library to speak OVSDB protocol
 """
 
-from __future__ import print_function
-
 import logging
 import operator
 import os
diff --git a/os_ken/lib/stringify.py b/os_ken/lib/stringify.py
index e178408b..6fa647c9 100644
--- a/os_ken/lib/stringify.py
+++ b/os_ken/lib/stringify.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import base64
 import inspect
 
diff --git a/os_ken/log.py b/os_ken/log.py
index e3a9bb3d..617627df 100644
--- a/os_ken/log.py
+++ b/os_ken/log.py
@@ -13,8 +13,6 @@
 # implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
-from __future__ import print_function
 from os_ken import cfg
 import inspect
 import platform
diff --git a/os_ken/services/protocols/bgp/api/all.py b/os_ken/services/protocols/bgp/api/all.py
index 6ffe65ce..c86cc4a2 100644
--- a/os_ken/services/protocols/bgp/api/all.py
+++ b/os_ken/services/protocols/bgp/api/all.py
@@ -1,7 +1,5 @@
 # flake8: noqa
 
-from __future__ import absolute_import
-
 from . import core
 from . import operator
 from . import prefix
diff --git a/os_ken/services/protocols/bgp/api/base.py b/os_ken/services/protocols/bgp/api/base.py
index 4e9a5835..e4d6686e 100644
--- a/os_ken/services/protocols/bgp/api/base.py
+++ b/os_ken/services/protocols/bgp/api/base.py
@@ -18,7 +18,6 @@
 
  This API can be used by various services like RPC, CLI, IoC, etc.
 """
-from __future__ import absolute_import
 
 import logging
 import traceback
diff --git a/os_ken/services/protocols/bgp/base.py b/os_ken/services/protocols/bgp/base.py
index 7e6f35f5..5e786f68 100644
--- a/os_ken/services/protocols/bgp/base.py
+++ b/os_ken/services/protocols/bgp/base.py
@@ -15,7 +15,6 @@
 """
   Defines some base class related to managing green threads.
 """
-from __future__ import absolute_import
 
 import abc
 from collections import OrderedDict
diff --git a/os_ken/services/protocols/bgp/bgp_sample_conf.py b/os_ken/services/protocols/bgp/bgp_sample_conf.py
index 34441644..8203cefe 100644
--- a/os_ken/services/protocols/bgp/bgp_sample_conf.py
+++ b/os_ken/services/protocols/bgp/bgp_sample_conf.py
@@ -1,6 +1,4 @@
 
-from __future__ import absolute_import
-
 import os
 
 from os_ken.services.protocols.bgp.bgpspeaker import RF_VPN_V4
diff --git a/os_ken/services/protocols/bgp/core_managers/__init__.py b/os_ken/services/protocols/bgp/core_managers/__init__.py
index 8b76bdc6..dbaf503c 100644
--- a/os_ken/services/protocols/bgp/core_managers/__init__.py
+++ b/os_ken/services/protocols/bgp/core_managers/__init__.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 from .configuration_manager import ConfigurationManager
 from .import_map_manager import ImportMapManager
 from .peer_manager import PeerManager
diff --git a/os_ken/services/protocols/bgp/operator/commands/show/rib.py b/os_ken/services/protocols/bgp/operator/commands/show/rib.py
index d648fa9f..5e918ba0 100644
--- a/os_ken/services/protocols/bgp/operator/commands/show/rib.py
+++ b/os_ken/services/protocols/bgp/operator/commands/show/rib.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import
 
 from os_ken.services.protocols.bgp.base import ActivityException
 from os_ken.services.protocols.bgp.operator.command import Command
diff --git a/os_ken/services/protocols/bgp/operator/commands/show/vrf.py b/os_ken/services/protocols/bgp/operator/commands/show/vrf.py
index d1308a94..f872bb6e 100644
--- a/os_ken/services/protocols/bgp/operator/commands/show/vrf.py
+++ b/os_ken/services/protocols/bgp/operator/commands/show/vrf.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import
 
 import logging
 import pprint
diff --git a/os_ken/services/protocols/zebra/db/__init__.py b/os_ken/services/protocols/zebra/db/__init__.py
index 7a0ba7f7..ca6ad4f6 100644
--- a/os_ken/services/protocols/zebra/db/__init__.py
+++ b/os_ken/services/protocols/zebra/db/__init__.py
@@ -17,8 +17,6 @@
 Database implementation for Zebra protocol service.
 """
 
-from __future__ import absolute_import
-
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
 
diff --git a/os_ken/services/protocols/zebra/db/base.py b/os_ken/services/protocols/zebra/db/base.py
index deda9916..dba51ccd 100644
--- a/os_ken/services/protocols/zebra/db/base.py
+++ b/os_ken/services/protocols/zebra/db/base.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import functools
 import logging
 
diff --git a/os_ken/services/protocols/zebra/db/interface.py b/os_ken/services/protocols/zebra/db/interface.py
index 430e2679..be1c6395 100644
--- a/os_ken/services/protocols/zebra/db/interface.py
+++ b/os_ken/services/protocols/zebra/db/interface.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import logging
 
 from sqlalchemy import Column
diff --git a/os_ken/services/protocols/zebra/db/route.py b/os_ken/services/protocols/zebra/db/route.py
index fdaa7c4e..936cb70b 100644
--- a/os_ken/services/protocols/zebra/db/route.py
+++ b/os_ken/services/protocols/zebra/db/route.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import logging
 import socket
 
diff --git a/os_ken/tests/integrated/bgp/base.py b/os_ken/tests/integrated/bgp/base.py
index 73e0bda5..b2a2a98a 100644
--- a/os_ken/tests/integrated/bgp/base.py
+++ b/os_ken/tests/integrated/bgp/base.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import logging
 import sys
 import unittest
diff --git a/os_ken/tests/integrated/bgp/base_ip6.py b/os_ken/tests/integrated/bgp/base_ip6.py
index 668a3acb..c4146c59 100644
--- a/os_ken/tests/integrated/bgp/base_ip6.py
+++ b/os_ken/tests/integrated/bgp/base_ip6.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import logging
 import sys
 import unittest
diff --git a/os_ken/tests/integrated/bgp/test_basic.py b/os_ken/tests/integrated/bgp/test_basic.py
index ba659890..3ad3260a 100644
--- a/os_ken/tests/integrated/bgp/test_basic.py
+++ b/os_ken/tests/integrated/bgp/test_basic.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import time
 
 from os_ken.tests.integrated.common import docker_base as ctn_base
diff --git a/os_ken/tests/integrated/bgp/test_ip6_basic.py b/os_ken/tests/integrated/bgp/test_ip6_basic.py
index 8affc687..6bfe1462 100644
--- a/os_ken/tests/integrated/bgp/test_ip6_basic.py
+++ b/os_ken/tests/integrated/bgp/test_ip6_basic.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import time
 
 from os_ken.tests.integrated.common import docker_base as ctn_base
diff --git a/os_ken/tests/integrated/common/docker_base.py b/os_ken/tests/integrated/common/docker_base.py
index 7a5088bf..7f0e545d 100644
--- a/os_ken/tests/integrated/common/docker_base.py
+++ b/os_ken/tests/integrated/common/docker_base.py
@@ -16,8 +16,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import itertools
 import logging
 import os
diff --git a/os_ken/tests/integrated/common/oskenbgp.py b/os_ken/tests/integrated/common/oskenbgp.py
index e209b74b..ca14ea54 100644
--- a/os_ken/tests/integrated/common/oskenbgp.py
+++ b/os_ken/tests/integrated/common/oskenbgp.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import logging
 import os
 import time
diff --git a/os_ken/tests/integrated/common/quagga.py b/os_ken/tests/integrated/common/quagga.py
index 9b6d2183..1e8221ea 100644
--- a/os_ken/tests/integrated/common/quagga.py
+++ b/os_ken/tests/integrated/common/quagga.py
@@ -16,8 +16,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import logging
 import os
 
diff --git a/os_ken/tests/integrated/run_test.py b/os_ken/tests/integrated/run_test.py
index b7330643..16172435 100644
--- a/os_ken/tests/integrated/run_test.py
+++ b/os_ken/tests/integrated/run_test.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import absolute_import
-
 import logging
 import os
 import sys
diff --git a/os_ken/tests/integrated/run_tests_with_ovs12.py b/os_ken/tests/integrated/run_tests_with_ovs12.py
index 3716f65c..3b78242e 100755
--- a/os_ken/tests/integrated/run_tests_with_ovs12.py
+++ b/os_ken/tests/integrated/run_tests_with_ovs12.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import unittest
 from nose.tools import ok_, eq_, timed, nottest
 
diff --git a/os_ken/tests/integrated/test_of_config.py b/os_ken/tests/integrated/test_of_config.py
index fa0afed4..70a4a342 100644
--- a/os_ken/tests/integrated/test_of_config.py
+++ b/os_ken/tests/integrated/test_of_config.py
@@ -110,8 +110,6 @@ Here is my sys.config used for this test.
 
 """
 
-from __future__ import print_function
-
 import traceback
 
 import lxml.etree
diff --git a/os_ken/tests/integrated/vrrp_common.py b/os_ken/tests/integrated/vrrp_common.py
index 65a58082..b496f033 100644
--- a/os_ken/tests/integrated/vrrp_common.py
+++ b/os_ken/tests/integrated/vrrp_common.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import time
 import random
 
diff --git a/os_ken/tests/packet_data_generator3/gen.py b/os_ken/tests/packet_data_generator3/gen.py
index 657c06c8..65067baf 100644
--- a/os_ken/tests/packet_data_generator3/gen.py
+++ b/os_ken/tests/packet_data_generator3/gen.py
@@ -1,7 +1,5 @@
 #! /usr/bin/env python
 
-from __future__ import print_function
-
 import getopt
 import os
 import re
diff --git a/os_ken/tests/unit/__init__.py b/os_ken/tests/unit/__init__.py
index 1e0569ed..b27b5457 100644
--- a/os_ken/tests/unit/__init__.py
+++ b/os_ken/tests/unit/__init__.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import
 
 # Note: The following import statement is defined in order to resolve
 # the conflict of the module names between 'os_ken.lib.ovs' and 'ovs'.
diff --git a/os_ken/tests/unit/ofproto/test_parser.py b/os_ken/tests/unit/ofproto/test_parser.py
index 51aa2131..aab5c7bd 100644
--- a/os_ken/tests/unit/ofproto/test_parser.py
+++ b/os_ken/tests/unit/ofproto/test_parser.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import six
 import sys
 import unittest
diff --git a/os_ken/tests/unit/ofproto/test_parser_compat.py b/os_ken/tests/unit/ofproto/test_parser_compat.py
index b7e0a1e5..b9f19024 100644
--- a/os_ken/tests/unit/ofproto/test_parser_compat.py
+++ b/os_ken/tests/unit/ofproto/test_parser_compat.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import six
 import sys
 import unittest
diff --git a/os_ken/tests/unit/ofproto/test_parser_ofpmatch.py b/os_ken/tests/unit/ofproto/test_parser_ofpmatch.py
index 13520fdf..d3c3ad7e 100644
--- a/os_ken/tests/unit/ofproto/test_parser_ofpmatch.py
+++ b/os_ken/tests/unit/ofproto/test_parser_ofpmatch.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 try:
     # Python 3
     from functools import reduce
diff --git a/os_ken/tests/unit/packet/test_bgp.py b/os_ken/tests/unit/packet/test_bgp.py
index 0ff07867..c6d601cd 100644
--- a/os_ken/tests/unit/packet/test_bgp.py
+++ b/os_ken/tests/unit/packet/test_bgp.py
@@ -14,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import logging
 import os
 import sys
diff --git a/os_ken/tests/unit/packet/test_geneve.py b/os_ken/tests/unit/packet/test_geneve.py
index 3ce65d71..8be23404 100644
--- a/os_ken/tests/unit/packet/test_geneve.py
+++ b/os_ken/tests/unit/packet/test_geneve.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import logging
 import os
 import sys
diff --git a/os_ken/tests/unit/packet/test_gre.py b/os_ken/tests/unit/packet/test_gre.py
index cb01d839..288fb0d1 100644
--- a/os_ken/tests/unit/packet/test_gre.py
+++ b/os_ken/tests/unit/packet/test_gre.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import logging
 import os
 import sys
diff --git a/os_ken/tests/unit/packet/test_openflow.py b/os_ken/tests/unit/packet/test_openflow.py
index fa30254f..10e6caf1 100644
--- a/os_ken/tests/unit/packet/test_openflow.py
+++ b/os_ken/tests/unit/packet/test_openflow.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import logging
 import os
 import sys
diff --git a/os_ken/tests/unit/packet/test_vrrp.py b/os_ken/tests/unit/packet/test_vrrp.py
index f6f4e1f4..2ebce295 100644
--- a/os_ken/tests/unit/packet/test_vrrp.py
+++ b/os_ken/tests/unit/packet/test_vrrp.py
@@ -16,8 +16,6 @@
 
 # vim: tabstop=4 shiftwidth=4 softtabstop=4
 
-from __future__ import print_function
-
 import unittest
 import logging
 import six
diff --git a/os_ken/tests/unit/packet/test_zebra.py b/os_ken/tests/unit/packet/test_zebra.py
index b1da5e09..d999b65c 100644
--- a/os_ken/tests/unit/packet/test_zebra.py
+++ b/os_ken/tests/unit/packet/test_zebra.py
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from __future__ import print_function
-
 import os
 import socket
 import sys