diff --git a/django/db/migrations/loader.py b/django/db/migrations/loader.py
index c0ac4b7f44..48166a1bdb 100644
--- a/django/db/migrations/loader.py
+++ b/django/db/migrations/loader.py
@@ -5,9 +5,6 @@ import sys
 from django.apps import apps
 from django.db.migrations.recorder import MigrationRecorder
 from django.db.migrations.graph import MigrationGraph
-from django.db.migrations.migration import Migration
-from django.db.migrations.state import ModelState
-from django.db.migrations import operations
 from django.utils import six
 from django.conf import settings
 
diff --git a/django/utils/translation/trans_real.py b/django/utils/translation/trans_real.py
index 4c98e7f8be..d3d7699dec 100644
--- a/django/utils/translation/trans_real.py
+++ b/django/utils/translation/trans_real.py
@@ -196,7 +196,7 @@ def translation(language):
     Returns a translation object.
     """
     global _translations
-    if not language in _translations:
+    if language not in _translations:
         _translations[language] = DjangoTranslation(language)
     return _translations[language]
 
diff --git a/tests/migrations/test_state.py b/tests/migrations/test_state.py
index afd2f8b8b9..ab65630105 100644
--- a/tests/migrations/test_state.py
+++ b/tests/migrations/test_state.py
@@ -347,6 +347,7 @@ class StateTests(TestCase):
 
         class TestModel(models.Model):
             ct = models.ForeignKey("contenttypes.ContentType")
+
             class Meta:
                 app_label = "migrations"
                 apps = new_apps