diff --git a/openedx/testing/coverage_context_listener/pytest_plugin.py b/openedx/testing/coverage_context_listener/pytest_plugin.py
index aa25ab0ca0..cdafa7df81 100644
--- a/openedx/testing/coverage_context_listener/pytest_plugin.py
+++ b/openedx/testing/coverage_context_listener/pytest_plugin.py
@@ -8,7 +8,7 @@ import requests
 from pavelib.utils.envs import Env
 
 
-class RemoteContextPlugin(object):
+class RemoteContextPlugin:
     """
     Pytest plugin for reporting pytests contexts to coverage running in another process
     """
@@ -31,7 +31,7 @@ class RemoteContextPlugin(object):
                 result = requests.post(
                     'http://{host}:{port}/coverage_context/update_context'.format(**cfg),
                     {
-                        'context': "{}|{}".format(item.nodeid, when),
+                        'context': f"{item.nodeid}|{when}",
                     }
                 )
                 assert result.status_code == 204
diff --git a/openedx/tests/completion_integration/test_handlers.py b/openedx/tests/completion_integration/test_handlers.py
index ef4016b269..677a751462 100644
--- a/openedx/tests/completion_integration/test_handlers.py
+++ b/openedx/tests/completion_integration/test_handlers.py
@@ -3,15 +3,14 @@ Test signal handlers for completion.
 """
 
 from datetime import datetime
+from unittest.mock import patch
 
 import ddt
 import pytest
-import six
 from completion import handlers
 from completion.models import BlockCompletion
 from completion.test_utils import CompletionSetUpMixin
 from django.test import TestCase
-from mock import patch
 from pytz import utc
 from xblock.completable import XBlockCompletionMode
 from xblock.core import XBlock
@@ -47,7 +46,7 @@ class ScorableCompletionHandlerTestCase(CompletionSetUpMixin, TestCase):
     COMPLETION_SWITCH_ENABLED = True
 
     def setUp(self):
-        super(ScorableCompletionHandlerTestCase, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         self.block_key = self.context_key.make_usage_key(block_type='problem', block_id='red')
 
     def call_scorable_block_completion_handler(self, block_key, score_deleted=None):
@@ -63,8 +62,8 @@ class ScorableCompletionHandlerTestCase(CompletionSetUpMixin, TestCase):
         handlers.scorable_block_completion(
             sender=self,
             user_id=self.user.id,
-            course_id=six.text_type(self.context_key),
-            usage_id=six.text_type(block_key),
+            course_id=str(self.context_key),
+            usage_id=str(block_key),
             weighted_earned=0.0,
             weighted_possible=3.0,
             modified=datetime.utcnow().replace(tzinfo=utc),
@@ -124,8 +123,8 @@ class ScorableCompletionHandlerTestCase(CompletionSetUpMixin, TestCase):
             grades_signals.PROBLEM_WEIGHTED_SCORE_CHANGED.send_robust(
                 sender=self,
                 user_id=self.user.id,
-                course_id=six.text_type(self.context_key),
-                usage_id=six.text_type(self.block_key),
+                course_id=str(self.context_key),
+                usage_id=str(self.block_key),
                 weighted_earned=0.0,
                 weighted_possible=3.0,
                 modified=datetime.utcnow().replace(tzinfo=utc),
@@ -143,15 +142,15 @@ class DisabledCompletionHandlerTestCase(CompletionSetUpMixin, TestCase):
     COMPLETION_SWITCH_ENABLED = False
 
     def setUp(self):
-        super(DisabledCompletionHandlerTestCase, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         self.block_key = self.context_key.make_usage_key(block_type='problem', block_id='red')
 
     def test_disabled_handler_does_not_submit_completion(self):
         handlers.scorable_block_completion(
             sender=self,
             user_id=self.user.id,
-            course_id=six.text_type(self.context_key),
-            usage_id=six.text_type(self.block_key),
+            course_id=str(self.context_key),
+            usage_id=str(self.block_key),
             weighted_earned=0.0,
             weighted_possible=3.0,
             modified=datetime.utcnow().replace(tzinfo=utc),
diff --git a/openedx/tests/completion_integration/test_models.py b/openedx/tests/completion_integration/test_models.py
index a0486d38db..8871272b3c 100644
--- a/openedx/tests/completion_integration/test_models.py
+++ b/openedx/tests/completion_integration/test_models.py
@@ -3,7 +3,6 @@ Test models, managers, and validators.
 """
 
 import pytest
-import six
 from completion import models
 from completion.test_utils import CompletionWaffleTestMixin, submit_completions_for_testing
 from completion.waffle import ENABLE_COMPLETION_TRACKING_SWITCH
@@ -11,7 +10,6 @@ from django.core.exceptions import ValidationError
 from django.test import TestCase
 from edx_toggles.toggles.testutils import override_waffle_switch
 from opaque_keys.edx.keys import CourseKey, UsageKey
-from six.moves import range, zip
 
 from common.djangoapps.student.tests.factories import CourseEnrollmentFactory, UserFactory
 from openedx.core.djangolib.testing.utils import skip_unless_lms
@@ -42,7 +40,7 @@ class CompletionSetUpMixin(CompletionWaffleTestMixin):
     """
     def set_up_completion(self):
         self.user = UserFactory()
-        self.block_key = UsageKey.from_string(u'block-v1:edx+test+run+type@video+block@doggos')
+        self.block_key = UsageKey.from_string('block-v1:edx+test+run+type@video+block@doggos')
         self.completion = models.BlockCompletion.objects.create(
             user=self.user,
             context_key=self.block_key.context_key,
@@ -59,7 +57,7 @@ class SubmitCompletionTestCase(CompletionSetUpMixin, TestCase):
     semantics.
     """
     def setUp(self):
-        super(SubmitCompletionTestCase, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         self.override_waffle_switch(True)
         self.set_up_completion()
 
@@ -100,7 +98,7 @@ class SubmitCompletionTestCase(CompletionSetUpMixin, TestCase):
         assert models.BlockCompletion.objects.count() == 2
 
     def test_new_block(self):
-        newblock = UsageKey.from_string(u'block-v1:edx+test+run+type@video+block@puppers')
+        newblock = UsageKey.from_string('block-v1:edx+test+run+type@video+block@puppers')
         with self.assertNumQueries(SELECT + UPDATE + 4 * SAVEPOINT):
             _, isnew = models.BlockCompletion.objects.submit_completion(
                 user=self.user,
@@ -128,7 +126,7 @@ class CompletionDisabledTestCase(CompletionSetUpMixin, TestCase):
     Tests that completion API is not called when the feature is disabled.
     """
     def setUp(self):
-        super(CompletionDisabledTestCase, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         # insert one completion record...
         self.set_up_completion()
         # ...then disable the feature.
@@ -152,13 +150,13 @@ class SubmitBatchCompletionTestCase(CompletionWaffleTestMixin, TestCase):
     semantics.
     """
     def setUp(self):
-        super(SubmitBatchCompletionTestCase, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         self.override_waffle_switch(True)
 
         self.block_key = UsageKey.from_string('block-v1:edx+test+run+type@video+block@doggos')
         self.course_key_obj = CourseKey.from_string('course-v1:edx+test+run')
         self.user = UserFactory()
-        CourseEnrollmentFactory.create(user=self.user, course_id=six.text_type(self.course_key_obj))
+        CourseEnrollmentFactory.create(user=self.user, course_id=str(self.course_key_obj))
 
     def test_submit_batch_completion(self):
         blocks = [(self.block_key, 1.0)]
@@ -194,14 +192,14 @@ class BatchCompletionMethodTests(CompletionWaffleTestMixin, TestCase):
     Tests for the classmethods that retrieve course/block completion data.
     """
     def setUp(self):
-        super(BatchCompletionMethodTests, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         self.override_waffle_switch(True)
 
         self.user = UserFactory.create()
         self.other_user = UserFactory.create()
         self.course_key = CourseKey.from_string("edX/MOOC101/2049_T2")
         self.other_course_key = CourseKey.from_string("course-v1:ReedX+Hum110+1904")
-        self.block_keys = [UsageKey.from_string("i4x://edX/MOOC101/video/{}".format(number)) for number in range(5)]
+        self.block_keys = [UsageKey.from_string(f"i4x://edX/MOOC101/video/{number}") for number in range(5)]
         self.block_keys_with_runs = [key.replace(course_key=self.course_key) for key in self.block_keys]
         self.other_course_block_keys = [self.other_course_key.make_usage_key('html', '1')]
 
diff --git a/openedx/tests/completion_integration/test_services.py b/openedx/tests/completion_integration/test_services.py
index bc382b4af7..fd23895d5a 100644
--- a/openedx/tests/completion_integration/test_services.py
+++ b/openedx/tests/completion_integration/test_services.py
@@ -8,7 +8,6 @@ from completion.models import BlockCompletion
 from completion.services import CompletionService
 from completion.test_utils import CompletionWaffleTestMixin
 from opaque_keys.edx.keys import CourseKey
-from six.moves import range
 
 from openedx.core.djangolib.testing.utils import skip_unless_lms
 from common.djangoapps.student.tests.factories import UserFactory
@@ -28,7 +27,7 @@ class CompletionServiceTestCase(CompletionWaffleTestMixin, SharedModuleStoreTest
 
     @classmethod
     def setUpClass(cls):
-        super(CompletionServiceTestCase, cls).setUpClass()
+        super().setUpClass()
         cls.course = CourseFactory.create()
         with cls.store.bulk_operations(cls.course.id):
             cls.chapter = ItemFactory.create(
@@ -80,7 +79,7 @@ class CompletionServiceTestCase(CompletionWaffleTestMixin, SharedModuleStoreTest
         cls.problems = [cls.problem, cls.problem2, cls.problem3, cls.problem4, cls.problem5]
 
     def setUp(self):
-        super(CompletionServiceTestCase, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         self.override_waffle_switch(True)
         self.user = UserFactory.create()
         self.other_user = UserFactory.create()
diff --git a/openedx/tests/completion_integration/test_views.py b/openedx/tests/completion_integration/test_views.py
index 971a502ecf..9fe8300070 100644
--- a/openedx/tests/completion_integration/test_views.py
+++ b/openedx/tests/completion_integration/test_views.py
@@ -1,11 +1,9 @@
-# -*- coding: utf-8 -*-
 """
 Test models, managers, and validators.
 """
 
 
 import ddt
-import six
 from completion.test_utils import CompletionWaffleTestMixin
 from completion.waffle import ENABLE_COMPLETION_TRACKING_SWITCH
 from django.urls import reverse
@@ -38,7 +36,7 @@ class CompletionBatchTestCase(CompletionWaffleTestMixin, ModuleStoreTestCase):
         """
         Create the test data.
         """
-        super(CompletionBatchTestCase, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         self.url = reverse('completion:v1:completion-batch')
 
         # Enable the waffle flag for all tests
@@ -49,21 +47,21 @@ class CompletionBatchTestCase(CompletionWaffleTestMixin, ModuleStoreTestCase):
             org='TestX', number='101', display_name='Test',
             default_store=ModuleStoreEnum.Type.split,
         )
-        assert six.text_type(self.course.id) == self.COURSE_KEY
+        assert str(self.course.id) == self.COURSE_KEY
         self.problem = ItemFactory.create(
             parent=self.course, category="problem", display_name="Test Problem", publish_item=False,
         )
-        assert six.text_type(self.problem.location) == self.BLOCK_KEY
+        assert str(self.problem.location) == self.BLOCK_KEY
         # And an old mongo course:
         self.course_deprecated = CourseFactory.create(
             org='TestX', number='201', display_name='Test',
             default_store=ModuleStoreEnum.Type.mongo,
         )
-        assert six.text_type(self.course_deprecated.id) == self.COURSE_KEY_DEPRECATED
+        assert str(self.course_deprecated.id) == self.COURSE_KEY_DEPRECATED
         self.problem_deprecated = ItemFactory.create(
             parent=self.course_deprecated, category="problem", display_name="Test Problem",
         )
-        assert six.text_type(self.problem_deprecated.location) == self.BLOCK_KEY_DEPRECATED
+        assert str(self.problem_deprecated.location) == self.BLOCK_KEY_DEPRECATED
 
         # Create users
         self.staff_user = UserFactory(is_staff=True)
@@ -152,8 +150,8 @@ class CompletionBatchTestCase(CompletionWaffleTestMixin, ModuleStoreTestCase):
             400,
             {
                 "detail": (
-                    u"Block with key: 'block-v1:TestX+101+OtherCourse+type@problem+block@other' "
-                    u"is not in context {}".format(COURSE_KEY)
+                    "Block with key: 'block-v1:TestX+101+OtherCourse+type@problem+block@other' "
+                    "is not in context {}".format(COURSE_KEY)
                 )
             }
         ),
diff --git a/openedx/tests/xblock_integration/test_crowdsource_hinter.py b/openedx/tests/xblock_integration/test_crowdsource_hinter.py
index b2c5c69685..3223a1da24 100644
--- a/openedx/tests/xblock_integration/test_crowdsource_hinter.py
+++ b/openedx/tests/xblock_integration/test_crowdsource_hinter.py
@@ -8,8 +8,6 @@ import unittest
 import simplejson as json
 from django.conf import settings
 from django.urls import reverse
-from six import text_type
-from six.moves import range
 
 from lms.djangoapps.courseware.tests.factories import GlobalStaffFactory
 from lms.djangoapps.courseware.tests.helpers import LoginEnrollmentTestCase
@@ -36,7 +34,7 @@ class TestCrowdsourceHinter(SharedModuleStoreTestCase, LoginEnrollmentTestCase):
         if settings.ROOT_URLCONF != 'lms.urls':
             raise unittest.SkipTest('Test only valid in lms')
 
-        super(TestCrowdsourceHinter, cls).setUpClass()
+        super().setUpClass()
         cls.course = CourseFactory.create(
             display_name='CrowdsourceHinter_Test_Course'
         )
@@ -59,16 +57,16 @@ class TestCrowdsourceHinter(SharedModuleStoreTestCase, LoginEnrollmentTestCase):
         cls.course_url = reverse(
             'courseware_section',
             kwargs={
-                'course_id': text_type(cls.course.id),
+                'course_id': str(cls.course.id),
                 'chapter': 'Overview',
                 'section': 'Welcome',
             }
         )
 
     def setUp(self):
-        super(TestCrowdsourceHinter, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         for idx, student in enumerate(self.STUDENTS):
-            username = "u{}".format(idx)
+            username = f"u{idx}"
             self.create_account(username, student['email'], student['password'])
             self.activate_user(student['email'])
 
@@ -81,8 +79,8 @@ class TestCrowdsourceHinter(SharedModuleStoreTestCase, LoginEnrollmentTestCase):
         if xblock_name is None:
             xblock_name = TestCrowdsourceHinter.XBLOCK_NAMES[0]
         return reverse('xblock_handler', kwargs={
-            'course_id': text_type(self.course.id),
-            'usage_id': quote_slashes(text_type(self.course.id.make_usage_key('crowdsourcehinter', xblock_name))),
+            'course_id': str(self.course.id),
+            'usage_id': quote_slashes(str(self.course.id.make_usage_key('crowdsourcehinter', xblock_name))),
             'handler': handler,
             'suffix': ''
         })
diff --git a/openedx/tests/xblock_integration/test_recommender.py b/openedx/tests/xblock_integration/test_recommender.py
index 9fe8c3b88b..cc1d9e6446 100644
--- a/openedx/tests/xblock_integration/test_recommender.py
+++ b/openedx/tests/xblock_integration/test_recommender.py
@@ -11,12 +11,9 @@ from copy import deepcopy
 from io import BytesIO
 
 import simplejson as json
-import six
 from ddt import data, ddt
 from django.conf import settings
 from django.urls import reverse
-from six import text_type
-from six.moves import range
 
 from lms.djangoapps.courseware.tests.factories import GlobalStaffFactory
 from lms.djangoapps.courseware.tests.helpers import LoginEnrollmentTestCase
@@ -43,7 +40,7 @@ class TestRecommender(SharedModuleStoreTestCase, LoginEnrollmentTestCase):
         if settings.ROOT_URLCONF != 'lms.urls':
             raise unittest.SkipTest('Test only valid in lms')
 
-        super(TestRecommender, cls).setUpClass()
+        super().setUpClass()
         cls.course = CourseFactory.create(
             display_name='Recommender_Test_Course'
         )
@@ -71,7 +68,7 @@ class TestRecommender(SharedModuleStoreTestCase, LoginEnrollmentTestCase):
         cls.course_url = reverse(
             'courseware_section',
             kwargs={
-                'course_id': text_type(cls.course.id),
+                'course_id': str(cls.course.id),
                 'chapter': 'Overview',
                 'section': 'Welcome',
             }
@@ -117,9 +114,9 @@ class TestRecommender(SharedModuleStoreTestCase, LoginEnrollmentTestCase):
         }
 
     def setUp(self):
-        super(TestRecommender, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         for idx, student in enumerate(self.STUDENTS):
-            username = "u{}".format(idx)
+            username = f"u{idx}"
             self.create_account(username, student['email'], student['password'])
             self.activate_user(student['email'])
             self.logout()
@@ -133,8 +130,8 @@ class TestRecommender(SharedModuleStoreTestCase, LoginEnrollmentTestCase):
         if xblock_name is None:
             xblock_name = TestRecommender.XBLOCK_NAMES[0]
         return reverse('xblock_handler', kwargs={
-            'course_id': text_type(self.course.id),
-            'usage_id': quote_slashes(text_type(self.course.id.make_usage_key('recommender', xblock_name))),
+            'course_id': str(self.course.id),
+            'usage_id': quote_slashes(str(self.course.id.make_usage_key('recommender', xblock_name))),
             'handler': handler,
             'suffix': ''
         })
@@ -209,7 +206,7 @@ class TestRecommenderCreateFromEmpty(TestRecommender):
         """
         self.enroll_student(self.STUDENTS[0]['email'], self.STUDENTS[0]['password'])
         # Check whether adding new resource is successful
-        for resource_id, resource in six.iteritems(self.test_recommendations):
+        for resource_id, resource in self.test_recommendations.items():
             for xblock_name in self.XBLOCK_NAMES:
                 result = self.call_event('add_resource', resource, xblock_name)
 
@@ -228,7 +225,7 @@ class TestRecommenderCreateFromEmpty(TestRecommender):
 class TestRecommenderResourceBase(TestRecommender):
     """Base helper class for tests with resources."""
     def setUp(self):
-        super(TestRecommenderResourceBase, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         self.resource_id = self.resource_urls[0]
         self.resource_id_second = self.resource_urls[1]
         self.non_existing_resource_id = 'An non-existing id'
@@ -251,7 +248,7 @@ class TestRecommenderResourceBase(TestRecommender):
         """
         resource = {"id": resource_id}
         edited_recommendations = {
-            key: value + "edited" for key, value in six.iteritems(self.test_recommendations[self.resource_id])
+            key: value + "edited" for key, value in self.test_recommendations[self.resource_id].items()
         }
         resource.update(edited_recommendations)
         return resource
@@ -634,7 +631,7 @@ class TestRecommenderFileUploading(TestRecommender):
     Check whether we can handle file uploading correctly
     """
     def setUp(self):
-        super(TestRecommenderFileUploading, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         self.initial_configuration = {
             'flagged_accum_resources': {},
             'endorsed_recommendation_reasons': [],
@@ -653,7 +650,7 @@ class TestRecommenderFileUploading(TestRecommender):
             f_handler = BytesIO(codecs.decode(test_case['magic_number'], 'hex_codec'))
         elif content is not None:
             f_handler = BytesIO(
-                json.dumps(content, sort_keys=True) if six.PY2 else json.dumps(content, sort_keys=True).encode('utf-8'))
+                json.dumps(content, sort_keys=True).encode('utf-8'))
         else:
             f_handler = BytesIO(b'')
 
diff --git a/openedx/tests/xblock_integration/xblock_testcase.py b/openedx/tests/xblock_integration/xblock_testcase.py
index 3f6503b712..d9e6d3cac8 100644
--- a/openedx/tests/xblock_integration/xblock_testcase.py
+++ b/openedx/tests/xblock_integration/xblock_testcase.py
@@ -43,13 +43,11 @@ import unittest
 from datetime import datetime, timedelta
 import html
 
-import mock
+from unittest import mock
 import pytz
-import six
 from bs4 import BeautifulSoup
 from django.conf import settings
 from django.urls import reverse
-from six.moves import range
 from xblock.plugin import Plugin
 
 import lms.djangoapps.lms_xblock.runtime
@@ -58,7 +56,7 @@ from xmodule.modulestore.tests.django_utils import SharedModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory, ItemFactory
 
 
-class XBlockEventTestMixin(object):
+class XBlockEventTestMixin:
     """Mixin for easily verifying that events were published during a
     test.
 
@@ -101,7 +99,7 @@ class XBlockEventTestMixin(object):
         passed into it.
 
         """
-        super(XBlockEventTestMixin, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         saved_init = lms.djangoapps.lms_xblock.runtime.LmsModuleSystem.__init__
 
         def patched_init(runtime_self, **kwargs):
@@ -166,7 +164,7 @@ class XBlockEventTestMixin(object):
         self.events = []
 
 
-class GradePublishTestMixin(object):
+class GradePublishTestMixin:
     '''
     This checks whether a grading event was correctly published. This
     puts basic plumbing in place, but we would like to:
@@ -188,7 +186,7 @@ class GradePublishTestMixin(object):
         '''
         Hot-patch the grading emission system to capture grading events.
         '''
-        super(GradePublishTestMixin, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
 
         def capture_score(user_id, usage_key, score, max_score):
             '''
@@ -218,7 +216,7 @@ class GradePublishTestMixin(object):
         assert grade == self.scores[(- 1)]['score']
 
 
-class XBlockScenarioTestCaseMixin(object):
+class XBlockScenarioTestCaseMixin:
     '''
     This allows us to have test cases defined in JSON today, and in OLX
     someday.
@@ -232,7 +230,7 @@ class XBlockScenarioTestCaseMixin(object):
         Create a set of pages with XBlocks on them. For now, we restrict
         ourselves to one block per learning sequence.
         """
-        super(XBlockScenarioTestCaseMixin, cls).setUpClass()
+        super().setUpClass()
 
         cls.course = CourseFactory.create(
             display_name='XBlock_Test_Course'
@@ -273,10 +271,10 @@ class XBlockScenarioTestCaseMixin(object):
                     )
                     cls.xblocks[xblock_config['urlname']] = xblock
 
-                scenario_url = six.text_type(reverse(
+                scenario_url = str(reverse(
                     'courseware_section',
                     kwargs={
-                        'course_id': six.text_type(cls.course.id),
+                        'course_id': str(cls.course.id),
                         'chapter': "ch_" + chapter_config['urlname'],
                         'section': "sec_" + chapter_config['urlname']
                     }
@@ -285,7 +283,7 @@ class XBlockScenarioTestCaseMixin(object):
                 cls.scenario_urls[chapter_config['urlname']] = scenario_url
 
 
-class XBlockStudentTestCaseMixin(object):
+class XBlockStudentTestCaseMixin:
     '''
     Creates a default set of students for XBlock tests
     '''
@@ -303,9 +301,9 @@ class XBlockStudentTestCaseMixin(object):
         users, so we exercise more corner cases, but we could
         standardize if this is more hassle than it's worth.
         """
-        super(XBlockStudentTestCaseMixin, self).setUp()  # lint-amnesty, pylint: disable=super-with-arguments
+        super().setUp()
         for idx, student in enumerate(self.student_list):
-            username = "u{}".format(idx)
+            username = f"u{idx}"
             self._enroll_user(username, student['email'], student['password'])
         self.select_student(0)
 
@@ -324,8 +322,8 @@ class XBlockStudentTestCaseMixin(object):
         """
         # If we don't have enough users, add a few more...
         for newuser_id in range(len(self.student_list), user_id):
-            username = "user_{i}".format(i=newuser_id)
-            email = "user_{i}@example.edx.org".format(i=newuser_id)
+            username = f"user_{newuser_id}"
+            email = f"user_{newuser_id}@example.edx.org"
             password = "12345"
             self._enroll_user(username, email, password)
             self.student_list.append({'email': email, 'password': password})
@@ -365,15 +363,15 @@ class XBlockTestCase(XBlockStudentTestCaseMixin,
         # So, skip the test class here if we are not in the LMS.
         if settings.ROOT_URLCONF != 'lms.urls':
             raise unittest.SkipTest('Test only valid in lms')
-        super(XBlockTestCase, cls).setUpClass()
+        super().setUpClass()
 
     def get_handler_url(self, handler, xblock_name=None):
         """
         Get url for the specified xblock handler
         """
         return reverse('xblock_handler', kwargs={
-            'course_id': six.text_type(self.course.id),
-            'usage_id': six.text_type(
+            'course_id': str(self.course.id),
+            'usage_id': str(
                 self.course.id.make_usage_key('done', xblock_name)
             ),
             'handler': handler,
@@ -413,9 +411,9 @@ class XBlockTestCase(XBlockStudentTestCaseMixin,
                 if block["urlname"] == xblock_name:
                     xblock_type = block["blocktype"]
 
-        key = six.text_type(self.course.id.make_usage_key(xblock_type, xblock_name))
+        key = str(self.course.id.make_usage_key(xblock_type, xblock_name))
         return reverse('xblock_handler', kwargs={
-            'course_id': six.text_type(self.course.id),
+            'course_id': str(self.course.id),
             'usage_id': key,
             'handler': handler,
             'suffix': ''
@@ -449,7 +447,7 @@ class XBlockTestCase(XBlockStudentTestCaseMixin,
         usage_id = self.xblocks[urlname].scope_ids.usage_id
         # First, we get out our <div>
         soup_html = BeautifulSoup(markup=content, features="lxml")
-        xblock_html = six.text_type(soup_html.find(id="seq_contents_0"))
+        xblock_html = str(soup_html.find(id="seq_contents_0"))
         # Now, we get out the text of the <div>
         try:
             escaped_html = xblock_html.split('<')[1].split('>')[1]