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: I3913e8876b34e112140788d7a405da6eedfb5f29

heatclient/common/base.py

@@ -293,7 +293,7 @@ class CrudManager(BaseManager):
 
     def _filter_kwargs(self, kwargs):
         """Drop null values and handle ids."""
-        for key, ref in six.iteritems(kwargs.copy()):
+        for key, ref in kwargs.copy().items():
             if ref is None:
                 kwargs.pop(key)
             else:
@@ -451,7 +451,7 @@ class Resource(object):
         return None
 
     def _add_details(self, info):
-        for (k, v) in six.iteritems(info):
+        for (k, v) in info.items():
             try:
                 setattr(self, k, v)
                 self._info[k] = v

heatclient/common/template_utils.py

@@ -144,7 +144,7 @@ def get_file_contents(from_data, files, base_url=None,
                               is_object, object_request)
 
     if isinstance(from_data, dict):
-        for key, value in six.iteritems(from_data):
+        for key, value in from_data.items():
             if ignore_if and ignore_if(key, value):
                 continue
 
@@ -351,7 +351,7 @@ def resolve_environment_urls(resource_registry, files, env_base_url,
     get_file_contents(rr, files, base_url, ignore_if,
                       is_object=is_object, object_request=object_request)
 
-    for res_name, res_dict in six.iteritems(rr.get('resources', {})):
+    for res_name, res_dict in rr.get('resources', {}).items():
         res_base_url = res_dict.get('base_url', base_url)
         get_file_contents(
             res_dict, files, res_base_url, ignore_if,

heatclient/common/utils.py

@@ -376,7 +376,7 @@ def format_parameter_file(param_files, template_file=None,
             template_file, template_url))
 
     param_file = {}
-    for key, value in six.iteritems(params):
+    for key, value in params.items():
                 param_file[key] = resolve_param_get_file(value,
                                                          template_base_url)
     return param_file

heatclient/tests/functional/osc/v1/base.py

@@ -48,7 +48,7 @@ class OpenStackClientTestBase(base.ClientTestBase):
         items = self.parser.listing(output)
         for item in items:
             obj[item['Field']] = six.text_type(item['Value'])
-        return dict((self._key_name(k), v) for k, v in six.iteritems(obj))
+        return dict((self._key_name(k), v) for k, v in obj.items())
 
     def _key_name(self, key):
         return key.lower().replace(' ', '_')
@@ -60,7 +60,7 @@ class OpenStackClientTestBase(base.ClientTestBase):
             if item['ID'] == id:
                 obj = item
                 break
-        return dict((self._key_name(k), v) for k, v in six.iteritems(obj))
+        return dict((self._key_name(k), v) for k, v in obj.items())
 
     def _stack_create(self, name, template, parameters=[], wait=True):
         cmd = 'stack create ' + name

heatclient/v1/events.py

@@ -15,7 +15,6 @@
 
 import collections
 from oslo_utils import encodeutils
-import six
 from six.moves.urllib import parse
 
 from heatclient.common import base
@@ -54,7 +53,7 @@ class EventManager(stacks.StackChildManager):
             filters = kwargs.pop('filters')
             params.update(filters)
 
-        for key, value in six.iteritems(kwargs):
+        for key, value in kwargs.items():
             if value:
                 params[key] = value
 

heatclient/v1/resources.py

@@ -14,7 +14,6 @@
 #    under the License.
 
 from oslo_utils import encodeutils
-import six
 from six.moves.urllib import parse
 
 from heatclient.common import base
@@ -60,7 +59,7 @@ class ResourceManager(stacks.StackChildManager):
             filters = kwargs.pop('filters')
             params.update(filters)
 
-        for key, value in six.iteritems(kwargs):
+        for key, value in kwargs.items():
             if value:
                 params[key] = value
 

heatclient/v1/software_configs.py

@@ -10,7 +10,6 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import six
 from six.moves.urllib import parse
 
 from heatclient.common import base
@@ -38,7 +37,7 @@ class SoftwareConfigManager(base.BaseManager):
         """
         qparams = {}
 
-        for opt, val in six.iteritems(kwargs):
+        for opt, val in kwargs.items():
             if val:
                 qparams[opt] = val
 

heatclient/v1/stacks.py

@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import six
 from six.moves.urllib import parse
 
 from heatclient._i18n import _
@@ -151,7 +150,7 @@ class StackManager(StackChildManager):
             filters = kwargs.pop('filters')
             params.update(filters)
 
-        for key, value in six.iteritems(kwargs):
+        for key, value in kwargs.items():
             if value:
                 params[key] = value