diff --git a/django/contrib/contenttypes/__init__.py b/django/contrib/contenttypes/__init__.py
index e061c232a1..5a04849f06 100644
--- a/django/contrib/contenttypes/__init__.py
+++ b/django/contrib/contenttypes/__init__.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
-from django.contrib.contenttypes.checks  import check_generic_foreign_keys
+from django.contrib.contenttypes.checks import check_generic_foreign_keys
 from django.core import checks
 
 
diff --git a/django/db/models/fields/related.py b/django/db/models/fields/related.py
index 570547cdcc..75e5f20fea 100644
--- a/django/db/models/fields/related.py
+++ b/django/db/models/fields/related.py
@@ -18,7 +18,6 @@ from django.utils.deprecation import RenameMethodsBase
 from django.utils.translation import ugettext_lazy as _
 from django.utils.functional import curry, cached_property
 from django.core import exceptions
-from django.apps import apps
 from django import forms
 
 RECURSIVE_RELATIONSHIP_CONSTANT = 'self'
diff --git a/tests/migrations/test_operations.py b/tests/migrations/test_operations.py
index 1a856a6f2d..eda356fd5d 100644
--- a/tests/migrations/test_operations.py
+++ b/tests/migrations/test_operations.py
@@ -218,7 +218,7 @@ class OperationTests(MigrationTestBase):
         self.assertEqual(field.default, NOT_PROVIDED)
         # Test the database alteration
         project_state.render().get_model("test_adflpd", "pony").objects.create(
-            weight = 4,
+            weight=4,
         )
         self.assertColumnNotExists("test_adflpd_pony", "height")
         with connection.schema_editor() as editor:
diff --git a/tests/migrations/test_state.py b/tests/migrations/test_state.py
index 276f404c11..5c71376179 100644
--- a/tests/migrations/test_state.py
+++ b/tests/migrations/test_state.py
@@ -35,6 +35,7 @@ class StateTests(TestCase):
 
         class SubAuthor(Author):
             width = models.FloatField(null=True)
+
             class Meta:
                 app_label = "migrations"
                 apps = new_apps