[2/3]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

The patch list:
    1. cells.
    2. compute api.
    3. image.
    4. network.
    5. objects.
    6. scheduler.
    7. virt.
    8. other resources.

Partial-Implements: blueprint replace-iteritems-with-items

Change-Id: Ic6e469eb80ee1774de1374bb36f38b5134b6b311

1 files changed, 4 insertions, 4 deletions

diff --git a/nova/block_device.py b/nova/block_device.py
index c6f1d1c773..a6ec93e300 100644
--- a/nova/block_device.py
+++ b/nova/block_device.py
@@ -17,7 +17,7 @@ import re
 
 from oslo_log import log as logging
 from oslo_utils import strutils
-import six
+
 
 import nova.conf
 from nova import exception
@@ -89,11 +89,11 @@ class BlockDeviceDict(dict):
             bdm_dict.get('delete_on_termination'))
         # NOTE (ndipanov): Never default db fields
         self.update({field: None for field in self._fields - do_not_default})
-        self.update(list(six.iteritems(bdm_dict)))
+        self.update(bdm_dict.items())
 
     def _validate(self, bdm_dict):
         """Basic data format validations."""
-        dict_fields = set(key for key, _ in six.iteritems(bdm_dict))
+        dict_fields = set(key for key, _ in bdm_dict.items())
 
         # Check that there are no bogus fields
         if not (dict_fields <=
@@ -139,7 +139,7 @@ class BlockDeviceDict(dict):
         non_computable_fields = set(['boot_index', 'disk_bus',
                                      'guest_format', 'device_type'])
 
-        new_bdm = {fld: val for fld, val in six.iteritems(legacy_bdm)
+        new_bdm = {fld: val for fld, val in legacy_bdm.items()
                    if fld in copy_over_fields}
 
         virt_name = legacy_bdm.get('virtual_name')