Handle move of ABCs to collections.abc

Resolves the following warning:

  DeprecationWarning: Using or importing the ABCs from 'collections'
  instead of from 'collections.abc' is deprecated, and in 3.8 it will
  stop working

Change-Id: Ib2214e7560cda1ef510c08859d5ee0726eb66b7b
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

horizon/base.py

@@ -52,6 +52,15 @@ from horizon.utils import settings as utils_settings
 DEFAULT_PANEL_GROUP = 'default'
 LOG = logging.getLogger(__name__)
 
+# Python 3.8 removes the ability to import the abstract base classes from
+# 'collections', but 'collections.abc' is not present in Python 2.7
+# TODO(stephenfin): Remove when we drop support for Python 2.7
+# pylint: disable=ungrouped-imports
+if hasattr(collections, 'abc'):
+    from collections.abc import Iterable
+else:
+    from collections import Iterable
+
 
 def _decorate_urlconf(urlpatterns, decorator, *args, **kwargs):
     for pattern in urlpatterns:
@@ -591,7 +600,7 @@ class Dashboard(Registry, HorizonComponent):
         default_created = False
         for panel_set in self.panels:
             # Instantiate PanelGroup classes.
-            if not isinstance(panel_set, collections.Iterable) and \
+            if not isinstance(panel_set, Iterable) and \
                     issubclass(panel_set, PanelGroup):
                 panel_group = panel_set(self)
             # Check for nested tuples, and convert them to PanelGroups

horizon/tables/base.py

@@ -48,6 +48,15 @@ from horizon.tables.actions import LinkAction
 from horizon.utils import html
 from horizon.utils import settings as utils_settings
 
+# Python 3.8 removes the ability to import the abstract base classes from
+# 'collections', but 'collections.abc' is not present in Python 2.7
+# TODO(stephenfin): Remove when we drop support for Python 2.7
+# pylint: disable=ungrouped-imports
+if hasattr(collections, 'abc'):
+    from collections.abc import Mapping
+else:
+    from collections import Mapping
+
 
 LOG = logging.getLogger(__name__)
 PALETTE = termcolors.PALETTES[termcolors.DEFAULT_PALETTE]
@@ -397,8 +406,7 @@ class Column(html.HTMLElement):
         if callable(self.transform):
             data = self.transform(datum)
         # Dict lookups
-        elif isinstance(datum, collections.Mapping) and \
-                self.transform in datum:
+        elif isinstance(datum, Mapping) and self.transform in datum:
             data = datum.get(self.transform)
         else:
             # Basic object lookups

horizon/test/helpers.py

@@ -45,6 +45,15 @@ from django.contrib.staticfiles.testing \
 
 from horizon import middleware
 
+# Python 3.8 removes the ability to import the abstract base classes from
+# 'collections', but 'collections.abc' is not present in Python 2.7
+# TODO(stephenfin): Remove when we drop support for Python 2.7
+# pylint: disable=ungrouped-imports
+if hasattr(collections, 'abc'):
+    from collections.abc import Mapping
+else:
+    from collections import Mapping
+
 
 LOG = logging.getLogger(__name__)
 
@@ -335,8 +344,8 @@ class update_settings(django_test_utils.override_settings):
         if keep_dict:
             for key, new_value in kwargs.items():
                 value = getattr(settings, key, None)
-                if (isinstance(new_value, collections.Mapping) and
-                        isinstance(value, collections.Mapping)):
+                if (isinstance(new_value, Mapping) and
+                        isinstance(value, Mapping)):
                     copied = copy.copy(value)
                     copied.update(new_value)
                     kwargs[key] = copied

openstack_dashboard/api/base.py

@@ -16,7 +16,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from collections import Sequence
+import collections
 import functools
 
 from django.conf import settings
@@ -25,6 +25,15 @@ import six
 
 from horizon import exceptions
 
+# Python 3.8 removes the ability to import the abstract base classes from
+# 'collections', but 'collections.abc' is not present in Python 2.7
+# TODO(stephenfin): Remove when we drop support for Python 2.7
+# pylint: disable=ungrouped-imports
+if hasattr(collections, 'abc'):
+    from collections.abc import Sequence
+else:
+    from collections import Sequence
+
 
 __all__ = ('APIResourceWrapper', 'APIDictWrapper',
            'get_service_from_catalog', 'url_for',)

openstack_dashboard/api/glance.py

@@ -39,6 +39,15 @@ from horizon.utils.memoized import memoized
 from openstack_dashboard.api import base
 from openstack_dashboard.contrib.developer.profiler import api as profiler
 
+# Python 3.8 removes the ability to import the abstract base classes from
+# 'collections', but 'collections.abc' is not present in Python 2.7
+# TODO(stephenfin): Remove when we drop support for Python 2.7
+# pylint: disable=ungrouped-imports
+if hasattr(collections, 'abc'):
+    from collections.abc import Iterable
+else:
+    from collections import Iterable
+
 
 LOG = logging.getLogger(__name__)
 VERSIONS = base.APIVersionManager("image", preferred_version=2)
@@ -125,7 +134,7 @@ class Image(base.APIResourceWrapper):
         # for v2), self._apiresource is not iterable. In that case,
         # the properties are included in the apiresource dict, so
         # just return that dict.
-        if not isinstance(self._apiresource, collections.Iterable):
+        if not isinstance(self._apiresource, Iterable):
             return self._apiresource.to_dict()
         image_dict = super(Image, self).to_dict()
         image_dict['is_public'] = self.is_public

openstack_dashboard/api/neutron.py

@@ -40,6 +40,15 @@ from openstack_dashboard.api import nova
 from openstack_dashboard.contrib.developer.profiler import api as profiler
 from openstack_dashboard import policy
 
+# Python 3.8 removes the ability to import the abstract base classes from
+# 'collections', but 'collections.abc' is not present in Python 2.7
+# TODO(stephenfin): Remove when we drop support for Python 2.7
+# pylint: disable=ungrouped-imports
+if hasattr(collections, 'abc'):
+    from collections.abc import Sequence
+else:
+    from collections import Sequence
+
 
 LOG = logging.getLogger(__name__)
 
@@ -854,14 +863,9 @@ def list_resources_with_long_filters(list_method,
         # filter_values) and do not consider other filter conditions
         # which may be specified in **params.
 
-        # NOTE(pas-ha) this will produce a deprecation warning in Py37
-        # and will not work in Py38, and six.moves also does not support it
-        # (see https://github.com/benjaminp/six/issues/155).
-        # TODO(pas-ha) replace with collections.abc.Sequence
-        # after dropping py27 support in U release
         if isinstance(filter_values, six.string_types):
             filter_values = [filter_values]
-        elif not isinstance(filter_values, collections.Sequence):
+        elif not isinstance(filter_values, Sequence):
             filter_values = list(filter_values)
 
         # Length of each query filter is:

openstack_dashboard/test/integration_tests/decorators.py

@@ -18,6 +18,15 @@ import testtools
 
 from openstack_dashboard.test.integration_tests import config
 
+# Python 3.8 removes the ability to import the abstract base classes from
+# 'collections', but 'collections.abc' is not present in Python 2.7
+# TODO(stephenfin): Remove when we drop support for Python 2.7
+# pylint: disable=ungrouped-imports
+if hasattr(collections, 'abc'):
+    from collections.abc import Iterable
+else:
+    from collections import Iterable
+
 
 def _is_test_method_name(method):
     return method.startswith('test_')
@@ -156,7 +165,7 @@ def skip_because(**kwargs):
     def actual_decoration(obj):
         skip_method = _get_skip_method(obj)
         bugs = kwargs.get("bugs")
-        if bugs and isinstance(bugs, collections.Iterable):
+        if bugs and isinstance(bugs, Iterable):
             for bug in bugs:
                 if not bug.isdigit():
                     raise ValueError("bug must be a valid bug number")