diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index d9737476df..3ceb670230 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/django/db/backends/postgresql_psycopg2/base.py
@@ -4,8 +4,6 @@ PostgreSQL database backend for Django.
 Requires psycopg 2: http://initd.org/projects/psycopg2
 """
 
-import sys
-
 from django.conf import settings
 from django.db.backends import (BaseDatabaseFeatures, BaseDatabaseWrapper,
     BaseDatabaseValidation)
diff --git a/tests/get_or_create/tests.py b/tests/get_or_create/tests.py
index 438e5cb164..3e70bdd482 100644
--- a/tests/get_or_create/tests.py
+++ b/tests/get_or_create/tests.py
@@ -19,40 +19,38 @@ class GetOrCreateTests(TestCase):
         )
 
     def test_get_or_create_method_with_get(self):
-        p, created = Person.objects.get_or_create(
+        created = Person.objects.get_or_create(
             first_name="John", last_name="Lennon", defaults={
                 "birthday": date(1940, 10, 9)
             }
-        )
+        )[1]
         self.assertFalse(created)
         self.assertEqual(Person.objects.count(), 1)
 
-
     def test_get_or_create_method_with_create(self):
-        p, created = Person.objects.get_or_create(
+        created = Person.objects.get_or_create(
             first_name='George', last_name='Harrison', defaults={
                 'birthday': date(1943, 2, 25)
             }
-        )
+        )[1]
         self.assertTrue(created)
         self.assertEqual(Person.objects.count(), 2)
 
-
     def test_get_or_create_redundant_instance(self):
         """
         If we execute the exact same statement twice, the second time,
         it won't create a Person.
         """
-        george, created = Person.objects.get_or_create(
+        Person.objects.get_or_create(
             first_name='George', last_name='Harrison', defaults={
                 'birthday': date(1943, 2, 25)
             }
         )
-        evil_george, created = Person.objects.get_or_create(
+        created = Person.objects.get_or_create(
             first_name='George', last_name='Harrison', defaults={
                 'birthday': date(1943, 2, 25)
             }
-        )
+        )[1]
 
         self.assertFalse(created)
         self.assertEqual(Person.objects.count(), 2)
@@ -67,6 +65,7 @@ class GetOrCreateTests(TestCase):
             Person.objects.get_or_create, first_name="Tom", last_name="Smith"
         )
 
+
 class GetOrCreateTestsWithManualPKs(TestCase):
 
     def setUp(self):
diff --git a/tests/prefetch_related/tests.py b/tests/prefetch_related/tests.py
index c953b0e46d..6732e45f40 100644
--- a/tests/prefetch_related/tests.py
+++ b/tests/prefetch_related/tests.py
@@ -1066,7 +1066,7 @@ class Ticket21760Tests(TestCase):
         for _ in range(3):
             house = House.objects.create()
             for _ in range(3):
-                self.rooms.append(Room.objects.create(house = house))
+                self.rooms.append(Room.objects.create(house=house))
 
     def test_bug(self):
         prefetcher = get_prefetcher(self.rooms[0], 'house')[0]
diff --git a/tests/test_discovery_sample/doctests.py b/tests/test_discovery_sample/doctests.py
index 3d228c6efb..4cc2a2105b 100644
--- a/tests/test_discovery_sample/doctests.py
+++ b/tests/test_discovery_sample/doctests.py
@@ -3,6 +3,7 @@ Doctest example from the official Python documentation.
 https://docs.python.org/3/library/doctest.html
 """
 
+
 def factorial(n):
     """Return the factorial of n, an exact integer >= 0.
 
@@ -35,7 +36,7 @@ def factorial(n):
         raise ValueError("n must be >= 0")
     if math.floor(n) != n:
         raise ValueError("n must be exact integer")
-    if n+1 == n:  # catch a value like 1e300
+    if n + 1 == n:  # catch a value like 1e300
         raise OverflowError("n too large")
     result = 1
     factor = 2
diff --git a/tests/test_runner/test_discover_runner.py b/tests/test_runner/test_discover_runner.py
index 809d4e16e9..975819508d 100644
--- a/tests/test_runner/test_discover_runner.py
+++ b/tests/test_runner/test_discover_runner.py
@@ -105,7 +105,6 @@ class DiscoverRunnerTest(TestCase):
 
     def test_testcase_ordering(self):
         suite = DiscoverRunner().build_suite(["test_discovery_sample/"])
-        tc_names = [case.__class__.__name__ for case in suite._tests]
         self.assertEqual(
             suite._tests[0].__class__.__name__,
             'TestDjangoTestCase',