Removed deprecated future imports (#24295)

cms/djangoapps/contentstore/courseware_index.py

@@ -1,11 +1,12 @@
 """ Code to allow module store to interface with courseware index """
 
-
 import logging
 import re
 from abc import ABCMeta, abstractmethod
 from datetime import timedelta
 
+from contentstore.course_group_config import GroupConfiguration
+from course_modes.models import CourseMode
 from django.conf import settings
 from django.urls import resolve
 from django.utils.translation import ugettext as _
@@ -13,14 +14,12 @@ from django.utils.translation import ugettext_lazy
 from eventtracking import tracker
 from search.search_engine_base import SearchEngine
 from six import add_metaclass, string_types, text_type
-
-from contentstore.course_group_config import GroupConfiguration
-from course_modes.models import CourseMode
-from openedx.core.lib.courses import course_image_url
 from xmodule.annotator_mixin import html_to_text
 from xmodule.library_tools import normalize_key_for_search
 from xmodule.modulestore import ModuleStoreEnum
 
+from openedx.core.lib.courses import course_image_url
+
 # REINDEX_AGE is the default amount of time that we look back for changes
 # that might have happened. If we are provided with a time at which the
 # indexing is triggered, then we know it is safe to only index items
@@ -59,11 +58,10 @@ class SearchIndexingError(Exception):
 
 
 @add_metaclass(ABCMeta)
-class SearchIndexerBase(object):
+class SearchIndexerBase(object, metaclass=ABCMeta):
     """
     Base class to perform indexing for courseware or library search from different modulestores
     """
-    __metaclass__ = ABCMeta
 
     INDEX_NAME = None
     DOCUMENT_TYPE = None