Stop using six library

Since we've dropped support for Python 2.7, it's time to look at
the bright future that Python 3.x will bring and stop forcing
compatibility with older versions.
This patch removes the six library from requirements, not
looking back.

Change-Id: I19384db89fc2a68376efc3f9f2e05fbd05046fd6

lower-constraints.txt

@@ -10,6 +10,5 @@ pbr==2.0.0
 PrettyTable==0.7.2
 Pygments==2.2.0
 requests==2.18.4
-six==1.10.0
 stestr==1.0.0
 testtools==2.2.0

metalsmith/_provisioner.py

@@ -17,7 +17,6 @@ import logging
 
 from openstack import connection
 from openstack import exceptions as os_exc
-import six
 
 from metalsmith import _instance
 from metalsmith import _nics
@@ -143,7 +142,7 @@ class Provisioner(object):
         """Create an allocation with given parameters."""
         if candidates:
             candidates = [
-                (node.id if not isinstance(node, six.string_types) else node)
+                (node.id if not isinstance(node, str) else node)
                 for node in candidates
             ]
 
@@ -370,7 +369,7 @@ class Provisioner(object):
         """
         if config is None:
             config = instance_config.GenericConfig()
-        if isinstance(image, six.string_types):
+        if isinstance(image, str):
             image = sources.GlanceImage(image)
 
         _utils.check_hostname(hostname)
@@ -620,7 +619,7 @@ class Provisioner(object):
 
     def _get_node(self, node, refresh=False):
         """A helper to find and return a node."""
-        if isinstance(node, six.string_types):
+        if isinstance(node, str):
             return self.connection.baremetal.get_node(node)
         elif hasattr(node, 'node'):
             # Instance object
@@ -635,7 +634,7 @@ class Provisioner(object):
 
     def _find_node_and_allocation(self, node, refresh=False):
         try:
-            if (not isinstance(node, six.string_types)
+            if (not isinstance(node, str)
                     or not _utils.is_hostname_safe(node)):
                 return self._get_node(node, refresh=refresh), None
 

metalsmith/_scheduler.py

@@ -17,8 +17,6 @@ import abc
 import collections
 import logging
 
-import six
-
 from metalsmith import _utils
 from metalsmith import exceptions
 
@@ -26,8 +24,7 @@ from metalsmith import exceptions
 LOG = logging.getLogger(__name__)
 
 
-@six.add_metaclass(abc.ABCMeta)
+class Filter(object, metaclass=abc.ABCMeta):
-class Filter(object):
     """Base class for filters."""
 
     @abc.abstractmethod

metalsmith/_utils.py

@@ -19,7 +19,6 @@ import re
 import sys
 
 from openstack import exceptions as os_exc
-import six
 
 from metalsmith import exceptions
 
@@ -89,7 +88,7 @@ def is_hostname_safe(hostname):
     :param hostname: The hostname to be validated.
     :returns: True if valid. False if not.
     """
-    if not isinstance(hostname, six.string_types) or len(hostname) > 255:
+    if not isinstance(hostname, str) or len(hostname) > 255:
         return False
 
     return _HOSTNAME_RE.match(hostname) is not None
@@ -144,4 +143,4 @@ def reraise_os_exc(reraise_as, failure_message='Clean up failed'):
     if is_expected:
         raise reraise_as(str(exc_info[1]))
     else:
-        six.reraise(*exc_info)
+        raise exc_info[1]

metalsmith/sources.py

@@ -18,11 +18,11 @@
 import abc
 import logging
 import os
+from urllib import parse as urlparse
 
 import openstack.exceptions
 import requests
-import six
+
-from six.moves.urllib import parse as urlparse
 
 from metalsmith import _utils
 from metalsmith import exceptions
@@ -31,8 +31,7 @@ from metalsmith import exceptions
 LOG = logging.getLogger(__name__)
 
 
-@six.add_metaclass(abc.ABCMeta)
+class _Source(object, metaclass=abc.ABCMeta):
-class _Source(object):
 
     def _validate(self, connection, root_size_gb):
         """Validate the source."""

metalsmith/test/test_cmd.py

@@ -13,12 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import io
 import json
 import tempfile
 
 import fixtures
 import mock
-import six
 import testtools
 
 from metalsmith import _cmd
@@ -146,7 +146,7 @@ class TestDeploy(testtools.TestCase):
 
         args = ['deploy', '--network', 'mynet', '--image', 'myimg',
                 '--resource-class', 'compute']
-        fake_io = six.StringIO()
+        fake_io = io.StringIO()
         with mock.patch('sys.stdout', fake_io):
             self._check(mock_pr, args, {}, {}, formatter='json')
             self.assertEqual(json.loads(fake_io.getvalue()),
@@ -601,7 +601,7 @@ class TestUndeploy(testtools.TestCase):
         node.to_dict.return_value = {'node': 'dict'}
 
         args = ['--format', 'json', 'undeploy', '123456']
-        fake_io = six.StringIO()
+        fake_io = io.StringIO()
         with mock.patch('sys.stdout', fake_io):
             _cmd.main(args)
             self.assertEqual(json.loads(fake_io.getvalue()),
@@ -747,7 +747,7 @@ class TestShowWait(testtools.TestCase):
         mock_pr.return_value.show_instances.return_value = self.instances
         args = ['--format', 'json', 'show', 'uuid1', 'hostname2']
 
-        fake_io = six.StringIO()
+        fake_io = io.StringIO()
         with mock.patch('sys.stdout', fake_io):
             _cmd.main(args)
             self.assertEqual(json.loads(fake_io.getvalue()),
@@ -773,7 +773,7 @@ class TestShowWait(testtools.TestCase):
         mock_pr.return_value.list_instances.return_value = self.instances
         args = ['--format', 'json', 'list']
 
-        fake_io = six.StringIO()
+        fake_io = io.StringIO()
         with mock.patch('sys.stdout', fake_io):
             _cmd.main(args)
             self.assertEqual(json.loads(fake_io.getvalue()),
@@ -786,7 +786,7 @@ class TestShowWait(testtools.TestCase):
             self.instances)
         args = ['--format', 'json', 'wait', 'uuid1', 'hostname2']
 
-        fake_io = six.StringIO()
+        fake_io = io.StringIO()
         with mock.patch('sys.stdout', fake_io):
             _cmd.main(args)
             self.assertEqual(json.loads(fake_io.getvalue()),

metalsmith/test/test_instance.py

@@ -14,7 +14,6 @@
 # limitations under the License.
 
 import mock
-import six
 
 from metalsmith import _instance
 from metalsmith.test import test_provisioner
@@ -136,7 +135,7 @@ class TestInstanceStates(test_provisioner.Base):
                           'uuid': self.node.id},
                          to_dict)
         # States are converted to strings
-        self.assertIsInstance(to_dict['state'], six.string_types)
+        self.assertIsInstance(to_dict['state'], str)
 
     @mock.patch.object(_instance.Instance, 'ip_addresses', autospec=True)
     def test_to_dict_with_allocation(self, mock_ips):
@@ -156,4 +155,4 @@ class TestInstanceStates(test_provisioner.Base):
                           'uuid': self.node.id},
                          to_dict)
         # States are converted to strings
-        self.assertIsInstance(to_dict['state'], six.string_types)
+        self.assertIsInstance(to_dict['state'], str)

requirements.txt

@@ -4,5 +4,4 @@
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 openstacksdk>=0.29.0 # Apache-2.0
 requests>=2.18.4 # Apache-2.0
-six>=1.10.0 # MIT
 PrettyTable<0.8,>=0.7.2 # BSD