Remove py2.7 support

The underlying library (charms.reactive) no longer support py27, and
reactive charms are only py35 and later supported.  Thus, there is no
reason to support py27 in charms.openstack.

Note: the zuul gate still has a py27 test so that is left in the tox.ini
but it simply evaluates to true.

Change-Id: I9a4e18038b706286f60e64fcf67f3e63a90feda9

charms_openstack/adapters.py

@@ -19,8 +19,6 @@ import itertools
 import re
 import weakref
 
-import six
-
 import charms.reactive as reactive
 import charms.reactive.bus
 import charmhelpers.contrib.hahelpers.cluster as ch_cluster
@@ -437,7 +435,7 @@ def make_default_configuration_adapter_class(base_cls=None,
     if not custom_properties:
         return base_cls
     # turns the functions into properties on the class
-    properties = {n: property(f) for n, f in six.iteritems(custom_properties)}
+    properties = {n: property(f) for n, f in custom_properties.items()}
     # build a custom class with the custom properties
     return type('DefaultConfigurationAdapter', (base_cls, ), properties)
 
@@ -466,8 +464,7 @@ class ConfigurationAdapter(object):
         if charm_instance is not None:
             self._charm_instance_weakref = weakref.ref(charm_instance)
         # copy over (statically) the items of the charms Juju configuration
-        _config = hookenv.config()
-        for k, v in six.iteritems(_config):
+        for k, v in hookenv.config().items():
             k = k.replace('-', '_')
             setattr(self, k, v)
 
@@ -850,7 +847,7 @@ def make_default_relation_adapter(base_cls, relation, properties):
     if not properties:
         return base_cls
     # convert the functions into properties
-    props = {n: property(f) for n, f in six.iteritems(properties)}
+    props = {n: property(f) for n, f in properties.items()}
     # turn 'my-Something_interface' into 'MySomethingInterface'
     # future proof incase other chars come in which can't be in an Python Class
     # name.
@@ -923,10 +920,9 @@ class OpenStackRelationAdapters(object):
         for cls in reversed(self.__class__.mro()):
             self._adapters.update(
                 {k.replace('-', '_'): v
-                 for k, v in six.iteritems(
-                     getattr(cls, 'relation_adapters', {}))})
+                 for k, v in getattr(cls, 'relation_adapters', {}).items()})
         # now we have to add in any customisations to those adapters
-        for relation, properties in six.iteritems(_custom_adapter_properties):
+        for relation, properties in _custom_adapter_properties.items():
             relation = relation.replace('-', '_')
             try:
                 cls = self._adapters[relation]

charms_openstack/charm.py

@@ -15,9 +15,6 @@
 # OpenStackCharm() - base class for build OpenStack charms from for the
 # reactive framework.
 
-# need/want absolute imports for the package imports to work properly
-from __future__ import absolute_import
-
 import base64
 import collections
 import contextlib
@@ -30,7 +27,6 @@ import string
 import subprocess
 
 import apt_pkg as apt
-import six
 
 import charmhelpers.contrib.network.ip as ch_ip
 import charmhelpers.contrib.openstack.templating as os_templating
@@ -478,8 +474,7 @@ class OpenStackCharmMeta(type):
         return _singleton
 
 
-@six.add_metaclass(OpenStackCharmMeta)
-class OpenStackCharm(object):
+class OpenStackCharm(object, metaclass=OpenStackCharmMeta):
     """
     Base class for all OpenStack Charm classes;
     encapulates general OpenStack charm payload operations
@@ -993,7 +988,7 @@ class OpenStackCharm(object):
         available_states = reactive.bus.get_states().keys()
         status = None
         messages = []
-        for relation, states in six.iteritems(states_to_check):
+        for relation, states in states_to_check.items():
             for state, err_status, err_msg in states:
                 if state not in available_states:
                     messages.append(err_msg)
@@ -1144,7 +1139,7 @@ class OpenStackCharm(object):
             return None
 
         vers_map = os_utils.OPENSTACK_CODENAMES
-        for version, cname in six.iteritems(vers_map):
+        for version, cname in vers_map.items():
             if cname == codename:
                 return version
 

tox.ini

@@ -26,7 +26,7 @@ basepython = python3.5
 deps = -r{toxinidir}/test-requirements.txt
 
 [testenv:pep8]
-basepython = python2.7
+basepython = python3.5
 deps = -r{toxinidir}/test-requirements.txt
 commands = flake8 {posargs} charms_openstack unit_tests
 

unit_tests/utils.py

@@ -18,14 +18,8 @@
 import contextlib
 import io
 import mock
-import six
 import unittest
 
-if not six.PY3:
-    builtin_open = '__builtin__.open'
-else:
-    builtin_open = 'builtins.open'
-
 
 @contextlib.contextmanager
 def patch_open():
@@ -41,7 +35,7 @@ def patch_open():
         mock_open(*args, **kwargs)
         yield mock_file
 
-    with mock.patch(builtin_open, stub_open):
+    with mock.patch('builtins.open', stub_open):
         yield mock_open, mock_file