Replace six.iteritems() with .items()

1.As mentioned in [1], we should avoid using six.iteritems to achieve iterators.
We can use dict.items instead, as it will return iterators in PY3 as well.
And dict.items/keys will more readable. 2.In py2, the performance about
list should be negligible, see the link [2].
[1] https://wiki.openstack.org/wiki/Python3
[2] http://lists.openstack.org/pipermail/openstack-dev/2015-June/066391.html

Change-Id: Ia235afc3532f62f265f91ca46d2306c72fc2a2a2

11 files changed, 14 insertions, 20 deletions

diff --git a/oslo_messaging/_drivers/amqp.py b/oslo_messaging/_drivers/amqp.py
index 071a004..01eeca6 100644
--- a/oslo_messaging/_drivers/amqp.py
+++ b/oslo_messaging/_drivers/amqp.py
@@ -89,9 +89,9 @@ def pack_context(msg, context):
 
     """
     if isinstance(context, dict):
-        context_d = six.iteritems(context)
+        context_d = context.items()
     else:
-        context_d = six.iteritems(context.to_dict())
+        context_d = context.to_dict().items()
 
     msg.update(('_context_%s' % key, value)
                for (key, value) in context_d)
diff --git a/oslo_messaging/_drivers/common.py b/oslo_messaging/_drivers/common.py
index a28e37c..7b0e402 100644
--- a/oslo_messaging/_drivers/common.py
+++ b/oslo_messaging/_drivers/common.py
@@ -89,7 +89,7 @@ class RPCException(Exception):
                 # log the issue and the kwargs
                 LOG.exception(_LE('Exception in string format operation, '
                                   'kwargs are:'))
-                for name, value in six.iteritems(kwargs):
+                for name, value in kwargs.items():
                     LOG.error("%s: %s", name, value)
                 # at least get the core message out if something happened
                 message = self.msg_fmt
diff --git a/oslo_messaging/_drivers/pika_driver/pika_message.py b/oslo_messaging/_drivers/pika_driver/pika_message.py
index 959f700..151fecf 100644
--- a/oslo_messaging/_drivers/pika_driver/pika_message.py
+++ b/oslo_messaging/_drivers/pika_driver/pika_message.py
@@ -344,7 +344,7 @@ class PikaOutgoingMessage(object):
         msg = self.message.copy()
 
         if self.context:
-            for key, value in six.iteritems(self.context):
+            for key, value in self.context.items():
                 key = six.text_type(key)
                 msg['_$_' + key] = value
 
diff --git a/oslo_messaging/_drivers/zmq_driver/server/zmq_incoming_message.py b/oslo_messaging/_drivers/zmq_driver/server/zmq_incoming_message.py
index 7ab0939..a7ddd09 100644
--- a/oslo_messaging/_drivers/zmq_driver/server/zmq_incoming_message.py
+++ b/oslo_messaging/_drivers/zmq_driver/server/zmq_incoming_message.py
@@ -12,8 +12,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import six
-
 from oslo_messaging._drivers import base
 
 
@@ -27,7 +25,7 @@ class ZmqIncomingMessage(base.RpcIncomingMessage):
         super(ZmqIncomingMessage, self).__init__(context, message)
         self._reply_method = kwargs.pop('reply_method',
                                         lambda self, reply, failure: None)
-        for key, value in six.iteritems(kwargs):
+        for key, value in kwargs.items():
             setattr(self, key, value)
 
     def acknowledge(self):
diff --git a/oslo_messaging/_drivers/zmq_driver/server/zmq_ttl_cache.py b/oslo_messaging/_drivers/zmq_driver/server/zmq_ttl_cache.py
index 91d5d41..fb4ddec 100644
--- a/oslo_messaging/_drivers/zmq_driver/server/zmq_ttl_cache.py
+++ b/oslo_messaging/_drivers/zmq_driver/server/zmq_ttl_cache.py
@@ -16,8 +16,6 @@ import logging
 import threading
 import time
 
-import six
-
 from oslo_messaging._drivers.zmq_driver import zmq_async
 
 LOG = logging.getLogger(__name__)
@@ -77,7 +75,7 @@ class TTLCache(object):
             old_size = len(self._cache)
             self._cache = \
                 {key: (value, expiration_time) for
-                 key, (value, expiration_time) in six.iteritems(self._cache)
+                 key, (value, expiration_time) in self._cache.items()
                  if not self._is_expired(expiration_time, current_time)}
             new_size = len(self._cache)
             LOG.debug('Updated cache: current size %(new_size)s '
diff --git a/oslo_messaging/notify/_impl_routing.py b/oslo_messaging/notify/_impl_routing.py
index c7136d0..8faf4ee 100644
--- a/oslo_messaging/notify/_impl_routing.py
+++ b/oslo_messaging/notify/_impl_routing.py
@@ -17,7 +17,6 @@ import logging
 
 from oslo_config import cfg
 from oslo_utils import fnmatch
-import six
 from stevedore import dispatch
 import yaml
 
@@ -88,9 +87,9 @@ class RoutingDriver(notifier.Driver):
         """
         accepted_drivers = set()
 
-        for driver, rules in six.iteritems(group):
+        for driver, rules in group.items():
             checks = []
-            for key, patterns in six.iteritems(rules):
+            for key, patterns in rules.items():
                 if key == 'accepted_events':
                     c = [fnmatch.fnmatch(event_type, p)
                          for p in patterns]
diff --git a/oslo_messaging/notify/middleware.py b/oslo_messaging/notify/middleware.py
index 60aab27..67f453f 100644
--- a/oslo_messaging/notify/middleware.py
+++ b/oslo_messaging/notify/middleware.py
@@ -23,7 +23,6 @@ import traceback as tb
 
 from oslo_config import cfg
 from oslo_middleware import base
-import six
 import webob.dec
 
 import oslo_messaging
@@ -73,7 +72,7 @@ class RequestNotifier(base.Middleware):
         include them.
 
         """
-        return dict((k, v) for k, v in six.iteritems(environ)
+        return dict((k, v) for k, v in environ.items()
                     if k.isupper() and k != 'HTTP_X_AUTH_TOKEN')
 
     @log_and_ignore_error
diff --git a/oslo_messaging/rpc/client.py b/oslo_messaging/rpc/client.py
index 5f6c64d..b746fbe 100644
--- a/oslo_messaging/rpc/client.py
+++ b/oslo_messaging/rpc/client.py
@@ -105,7 +105,7 @@ class _BaseCallContext(object):
         msg = dict(method=method)
 
         msg['args'] = dict()
-        for argname, arg in six.iteritems(args):
+        for argname, arg in args.items():
             msg['args'][argname] = self.serializer.serialize_entity(ctxt, arg)
 
         if self.target.namespace is not None:
diff --git a/oslo_messaging/rpc/dispatcher.py b/oslo_messaging/rpc/dispatcher.py
index 91b62a3..06c72a7 100644
--- a/oslo_messaging/rpc/dispatcher.py
+++ b/oslo_messaging/rpc/dispatcher.py
@@ -186,7 +186,7 @@ class RPCDispatcher(dispatcher.DispatcherBase):
     def _do_dispatch(self, endpoint, method, ctxt, args):
         ctxt = self.serializer.deserialize_context(ctxt)
         new_args = dict()
-        for argname, arg in six.iteritems(args):
+        for argname, arg in args.items():
             new_args[argname] = self.serializer.deserialize_entity(ctxt, arg)
         func = getattr(endpoint, method)
         result = func(ctxt, **new_args)
diff --git a/oslo_messaging/tests/utils.py b/oslo_messaging/tests/utils.py
index c5fca87..d8c0f4d 100644
--- a/oslo_messaging/tests/utils.py
+++ b/oslo_messaging/tests/utils.py
@@ -24,7 +24,7 @@ import threading
 from oslo_config import cfg
 from oslotest import base
 from oslotest import moxstubout
-import six
+
 
 TRUE_VALUES = ('true', '1', 'yes')
 
@@ -59,7 +59,7 @@ class BaseTestCase(base.BaseTestCase):
         test by the tearDown() method.
         """
         group = kw.pop('group', None)
-        for k, v in six.iteritems(kw):
+        for k, v in kw.items():
             self.conf.set_override(k, v, group, enforce_type=True)
 
 
diff --git a/oslo_messaging/transport.py b/oslo_messaging/transport.py
index c1361e7..b740820 100644
--- a/oslo_messaging/transport.py
+++ b/oslo_messaging/transport.py
@@ -411,7 +411,7 @@ class TransportURL(object):
 
         query = {}
         if url.query:
-            for key, values in six.iteritems(parse.parse_qs(url.query)):
+            for key, values in parse.parse_qs(url.query).items():
                 query[key] = ','.join(values)
 
         virtual_host = None