incr-268 (#20571)

* run python modernize

* run isort

lms/djangoapps/rss_proxy/admin.py

 """
 Admin module for the rss_proxy djangoapp.
 """
+from __future__ import absolute_import
+
 from django.contrib import admin
 
 from rss_proxy.models import WhitelistedRssUrl

lms/djangoapps/rss_proxy/migrations/0001_initial.py

 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
+from __future__ import absolute_import
 from django.db import migrations, models
 import django.utils.timezone
 import model_utils.fields

lms/djangoapps/rss_proxy/models.py

 """
 Models for the rss_proxy djangoapp.
 """
+from __future__ import absolute_import
+
+import six
 from django.db import models
 from model_utils.models import TimeStampedModel
 
@@ -19,4 +22,4 @@ class WhitelistedRssUrl(TimeStampedModel):
         app_label = "rss_proxy"
 
     def __unicode__(self):
-        return unicode(self.url)
+        return six.text_type(self.url)

lms/djangoapps/rss_proxy/tests/test_models.py

 """
 Tests for the rss_proxy models
 """
+from __future__ import absolute_import
+
+import six
 from django.test import TestCase
 
 from rss_proxy.models import WhitelistedRssUrl
@@ -17,4 +20,4 @@ class WhitelistedRssUrlTests(TestCase):
         """
         Test the unicode function returns the url
         """
-        self.assertEqual(unicode(self.whitelisted_rss_url), self.whitelisted_rss_url.url)
+        self.assertEqual(six.text_type(self.whitelisted_rss_url), self.whitelisted_rss_url.url)

lms/djangoapps/rss_proxy/tests/test_views.py

 """
 Tests for the rss_proxy views
 """
-from __future__ import print_function
-from django.urls import reverse
+from __future__ import absolute_import, print_function
+
 from django.test import TestCase
+from django.urls import reverse
 from mock import Mock, patch
 
 from rss_proxy.models import WhitelistedRssUrl

lms/djangoapps/rss_proxy/urls.py

 """
 URLs for the rss_proxy djangoapp.
 """
+from __future__ import absolute_import
+
 from django.conf.urls import url
 
 from rss_proxy.views import proxy

lms/djangoapps/rss_proxy/views.py

 """
 Views for the rss_proxy djangoapp.
 """
-from __future__ import print_function
+from __future__ import absolute_import, print_function
+
 import requests
 from django.conf import settings
 from django.core.cache import cache