Remove usage of six

Remove six-library Replace the following items with Python 3 style code.
- six.six.add_metaclass
- six.PY2
- requirement.txt

Change-Id: Ib87394e41cdba7fc57e6ae6ed08ba1f84465441e

neutron_fwaas/__init__.py

@@ -15,10 +15,5 @@
 
 import gettext
 
-import six
 
-
-if six.PY2:
-    gettext.install('neutron', unicode=1)
-else:
-    gettext.install('neutron')
+gettext.install('neutron')

neutron_fwaas/extensions/firewall_v2.py

@@ -22,7 +22,6 @@ from neutron_lib.api import extensions
 from neutron_lib.exceptions import firewall_v2 as f_exc
 from neutron_lib.services import base as service_base
 from oslo_config import cfg
-import six
 
 from neutron_fwaas._i18n import _
 from neutron_fwaas.common import fwaas_constants
@@ -221,8 +220,9 @@ class Firewall_v2(extensions.APIExtensionDescriptor):
         return Firewallv2PluginBase
 
 
-@six.add_metaclass(abc.ABCMeta)
-class Firewallv2PluginBase(service_base.ServicePluginBase):
+class Firewallv2PluginBase(
+    service_base.ServicePluginBase,
+    metaclass=abc.ABCMeta):
 
     def get_plugin_type(self):
         return fwaas_constants.FIREWALL_V2

neutron_fwaas/services/firewall/service_drivers/agents/drivers/conntrack_base.py

@@ -15,7 +15,6 @@
 
 import abc
 
-import six
 
 from neutron_lib.utils import runtime
 from oslo_config import cfg
@@ -38,8 +37,7 @@ def load_and_init_conntrack_driver(*args, **kwargs):
     return conntrack_driver
 
 
-@six.add_metaclass(abc.ABCMeta)
-class ConntrackDriverBase(object):
+class ConntrackDriverBase(object, metaclass=abc.ABCMeta):
     """Base Driver for Conntrack"""
 
     @abc.abstractmethod

neutron_fwaas/services/firewall/service_drivers/agents/drivers/fwaas_base.py

@@ -15,11 +15,8 @@
 
 import abc
 
-import six
 
-
-@six.add_metaclass(abc.ABCMeta)
-class FwaasDriverBase(object):
+class FwaasDriverBase(object, metaclass=abc.ABCMeta):
     """Firewall as a Service Driver base class.
 
     Using FwaasDriver Class, an instance of L3 perimeter Firewall

neutron_fwaas/services/firewall/service_drivers/agents/drivers/fwaas_base_v2.py

@@ -15,11 +15,8 @@
 
 import abc
 
-import six
 
-
-@six.add_metaclass(abc.ABCMeta)
-class FwaasDriverBase(object):
+class FwaasDriverBase(object, metaclass=abc.ABCMeta):
     """Firewall as a Service Driver base class.
 
     Using FwaasDriver Class, an instance of L3 perimeter Firewall

neutron_fwaas/services/firewall/service_drivers/agents/drivers/linux/l2/driver_base.py

@@ -15,11 +15,8 @@
 import abc
 import contextlib
 
-import six
 
-
-@six.add_metaclass(abc.ABCMeta)
-class FirewallL2DriverBase(object):
+class FirewallL2DriverBase(object, metaclass=abc.ABCMeta):
     """Abstract firewall L2 driver base"""
 
     def __init__(self, integration_bridge, sg_enabled=False):

neutron_fwaas/services/firewall/service_drivers/driver_api.py

@@ -16,7 +16,6 @@
 import abc
 import copy
 
-import six
 
 from neutron_lib.callbacks import events
 from neutron_lib.callbacks import registry
@@ -31,8 +30,7 @@ from neutron_fwaas.db.firewall.v2 import firewall_db_v2
 LOG = logging.getLogger(__name__)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class FirewallDriver(object):
+class FirewallDriver(object, metaclass=abc.ABCMeta):
     """Firewall v2 interface for driver
 
     That driver interface does not persist Firewall v2 data in any database.
@@ -124,8 +122,7 @@ class FirewallDriver(object):
         pass
 
 
-@six.add_metaclass(abc.ABCMeta)
-class FirewallDriverDBMixin(FirewallDriver):
+class FirewallDriverDBMixin(FirewallDriver, metaclass=abc.ABCMeta):
     """FirewallDriverDB mixin to provision the database on behalf of the driver
 
     That driver interface persists Firewall data in its database and forwards
@@ -519,8 +516,7 @@ class FirewallDriverDB(FirewallDriverDBMixin):
         pass
 
 
-@six.add_metaclass(abc.ABCMeta)
-class FirewallDriverRPCMixin(object):
+class FirewallDriverRPCMixin(object, metaclass=abc.ABCMeta):
     """FirewallAgent interface for driver with rpc callback listener.
 
     Each firewall backend driver that needs a rpc callback listener should

requirements.txt

@@ -11,7 +11,6 @@ eventlet!=0.18.3,!=0.20.1,>=0.18.2 # MIT
 netaddr>=0.7.18 # BSD
 SQLAlchemy>=1.4.23 # MIT
 alembic>=1.6.5 # MIT
-six>=1.10.0 # MIT
 neutron-lib>=1.26.0 # Apache-2.0
 os-ken >= 0.3.0 # Apache-2.0
 oslo.config>=5.2.0 # Apache-2.0