Import ABC classes from collection.abc

ABC classes should be imported from "collections.abc", not
"collections".

Closes-Bug: #1936667
Change-Id: I863f21b310fdf39030b13e2926e947b16043851a

neutron/agent/ovsdb/api.py

@@ -12,13 +12,13 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import collections
+from collections import abc
 import uuid
 
 
 def val_to_py(val):
     """Convert a json ovsdb return value to native python object"""
-    if isinstance(val, collections.Sequence) and len(val) == 2:
+    if isinstance(val, abc.Sequence) and len(val) == 2:
         if val[0] == "uuid":
             return uuid.UUID(val[1])
         elif val[0] == "set":

neutron/objects/base.py

@@ -12,6 +12,7 @@
 
 import abc
 import collections
+from collections import abc as collections_abc
 import copy
 import functools
 import itertools
@@ -282,7 +283,7 @@ class NeutronObject(obj_base.VersionedObject,
 
     @classmethod
     def _update_objects(cls, objects, values):
-        if not isinstance(objects, collections.Sequence):
+        if not isinstance(objects, collections_abc.Sequence):
             objects = (objects, )
 
         for obj in objects:

neutron/policy.py

@@ -13,7 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import collections
+from collections import abc
 import itertools
 import re
 import sys
@@ -142,7 +142,7 @@ def _is_attribute_explicitly_set(attribute_name, resource, target, action):
 def _should_validate_sub_attributes(attribute, sub_attr):
     """Verify that sub-attributes are iterable and should be validated."""
     validate = attribute.get('validate')
-    return (validate and isinstance(sub_attr, collections.Iterable) and
+    return (validate and isinstance(sub_attr, abc.Iterable) and
             any([k.startswith('type:dict') and
                  v for (k, v) in validate.items()]))
 

neutron/tests/unit/objects/test_base.py

@@ -11,6 +11,7 @@
 #    under the License.
 
 import collections
+from collections import abc
 import copy
 import itertools
 import random
@@ -672,7 +673,7 @@ class _BaseObjectTestCase(object):
                     objs or self.objs):
                 val = v() if callable(v) else v
                 db_obj_key = obj.fields_need_translation.get(k, k)
-                if isinstance(val, collections.Mapping):
+                if isinstance(val, abc.Mapping):
                     self.update_obj_fields(
                         val, db_obj[db_obj_key], fields[k], obj[k])
                 else: