INCR-294 Run python-modernize on lms/djangoapps/bulk_enroll (#20601)

* run python modernize

* run isort

* Fix python

lms/djangoapps/bulk_enroll/serializers.py

 """
 Serializers for Bulk Enrollment.
 """
+from __future__ import absolute_import
+
 from opaque_keys import InvalidKeyError
 from opaque_keys.edx.keys import CourseKey
-from openedx.core.djangoapps.course_groups.cohorts import is_cohort_exists
 from rest_framework import serializers
+from six.moves import zip
+
+from openedx.core.djangoapps.course_groups.cohorts import is_cohort_exists
 
 
 class StringListField(serializers.ListField):

lms/djangoapps/bulk_enroll/tests/test_views.py

 """
 Tests for the Bulk Enrollment views.
 """
-import ddt
+from __future__ import absolute_import
+
 import json
+
+import ddt
+import six
 from django.conf import settings
 from django.contrib.auth.models import User
 from django.core import mail
-from django.urls import reverse
 from django.test.utils import override_settings
+from django.urls import reverse
+from opaque_keys.edx.keys import CourseKey
 from rest_framework.test import APIRequestFactory, APITestCase, force_authenticate
 
 from bulk_enroll.serializers import BulkEnrollmentSerializer
 from bulk_enroll.views import BulkEnrollView
 from courseware.tests.helpers import LoginEnrollmentTestCase
-from opaque_keys.edx.keys import CourseKey
 from openedx.core.djangoapps.course_groups.cohorts import get_cohort_id
 from openedx.core.djangoapps.course_groups.tests.helpers import config_course_cohorts
 from openedx.core.djangoapps.site_configuration.helpers import get_value as get_site_value
-from student.models import (
-    CourseEnrollment,
-    ManualEnrollmentAudit,
-    ENROLLED_TO_UNENROLLED,
-    UNENROLLED_TO_ENROLLED,
-)
+from student.models import ENROLLED_TO_UNENROLLED, UNENROLLED_TO_ENROLLED, CourseEnrollment, ManualEnrollmentAudit
 from student.tests.factories import UserFactory
 from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory
@@ -55,7 +54,7 @@ class BulkEnrollmentTest(ModuleStoreTestCase, LoginEnrollmentTestCase, APITestCa
         )
 
         self.course = CourseFactory.create()
-        self.course_key = unicode(self.course.id)
+        self.course_key = six.text_type(self.course.id)
         self.enrolled_student = UserFactory(username='EnrolledStudent', first_name='Enrolled', last_name='Student')
         CourseEnrollment.enroll(
             self.enrolled_student,

lms/djangoapps/bulk_enroll/urls.py

 """
 URLs for the Bulk Enrollment API
 """
+from __future__ import absolute_import
+
 from django.conf.urls import url
 
 from bulk_enroll.views import BulkEnrollView

lms/djangoapps/bulk_enroll/views.py

 """
 API views for Bulk Enrollment
 """
+from __future__ import absolute_import
+
 import itertools
 import json
 
 from edx_rest_framework_extensions.auth.jwt.authentication import JwtAuthentication
+from opaque_keys import InvalidKeyError
+from opaque_keys.edx.keys import CourseKey
 from rest_framework import status
 from rest_framework.response import Response
 from rest_framework.views import APIView
@@ -12,12 +16,7 @@ from rest_framework.views import APIView
 from bulk_enroll.serializers import BulkEnrollmentSerializer
 from enrollment.views import EnrollmentUserThrottle
 from instructor.views.api import students_update_enrollment
-from opaque_keys import InvalidKeyError
-from opaque_keys.edx.keys import CourseKey
-from openedx.core.djangoapps.course_groups.cohorts import (
-    get_cohort_by_name,
-    add_user_to_cohort,
-)
+from openedx.core.djangoapps.course_groups.cohorts import add_user_to_cohort, get_cohort_by_name
 from openedx.core.djangoapps.course_groups.models import CourseUserGroup
 from openedx.core.lib.api.authentication import OAuth2Authentication
 from openedx.core.lib.api.permissions import IsStaff