Remove usage of six

Remove six-library Replace the following items with Python 3 style code.
- six.raise_from
- six.StringIO
- six.moves
- requirement.txt

Change-Id: If3d810a1dbe7d506aa55cc07717babec8393b8c5

osc_placement/http.py

@@ -16,7 +16,6 @@ import logging
 import keystoneauth1.exceptions.http as ks_exceptions
 import osc_lib.exceptions as exceptions
 import simplejson as json
-import six
 
 from osc_placement import version
 
@@ -42,7 +41,7 @@ def _wrap_http_exceptions():
             msg = detail.split('\n')[-1].strip()
             exc_class = _http_error_to_exc.get(exc.http_status,
                                                exceptions.CommandError)
-            six.raise_from(exc_class(exc.http_status, msg), exc)
+            raise exc_class(exc.http_status, msg) from exc
         else:
             raise
 

osc_placement/resources/common.py

@@ -10,7 +10,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from six.moves.urllib import parse as urlparse
+from urllib import parse as urlparse
 
 
 def encode(value, encoding='utf-8'):

osc_placement/tests/functional/base.py

@@ -10,11 +10,11 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import io
 import logging
 import random
 
 import fixtures
-import six
 
 from openstackclient import shell
 from oslotest import base
@@ -93,8 +93,8 @@ class BaseTestCase(base.BaseTestCase):
 
         # Context manager here instead of setUp because we only want
         # output trapping around the run().
-        self.output = six.StringIO()
-        self.error = six.StringIO()
+        self.output = io.StringIO()
+        self.error = io.StringIO()
         stdout_fix = fixtures.MonkeyPatch('sys.stdout', self.output)
         stderr_fix = fixtures.MonkeyPatch('sys.stderr', self.error)
         with stdout_fix, stderr_fix:

requirements.txt

@@ -3,7 +3,6 @@
 # process, which may cause wedges in the gate later.
 
 pbr>=2.0.0 # Apache-2.0
-six>=1.10.0 # MIT
 keystoneauth1>=3.3.0 # Apache-2.0
 simplejson>=3.16.0 # MIT
 osc-lib>=1.2.0  # Apache-2.0