diff --git a/django/contrib/auth/middleware.py b/django/contrib/auth/middleware.py
index f38efdd1d2..a107055e34 100644
--- a/django/contrib/auth/middleware.py
+++ b/django/contrib/auth/middleware.py
@@ -58,7 +58,7 @@ class RemoteUserMiddleware(object):
                         auth.BACKEND_SESSION_KEY, ''))
                     if isinstance(stored_backend, RemoteUserBackend):
                         auth.logout(request)
-                except ImproperlyConfigured as e:
+                except ImproperlyConfigured:
                     # backend failed to load
                     auth.logout(request)
             return
diff --git a/django/contrib/auth/models.py b/django/contrib/auth/models.py
index 309a7a590f..4c88e7d1ba 100644
--- a/django/contrib/auth/models.py
+++ b/django/contrib/auth/models.py
@@ -6,7 +6,6 @@ from django.core import validators
 from django.db import models
 from django.db.models.manager import EmptyManager
 from django.utils.crypto import get_random_string
-from django.utils.http import urlquote
 from django.utils import six
 from django.utils.translation import ugettext_lazy as _
 from django.utils import timezone
diff --git a/django/contrib/gis/forms/fields.py b/django/contrib/gis/forms/fields.py
index 28c89f35fd..55b887a445 100644
--- a/django/contrib/gis/forms/fields.py
+++ b/django/contrib/gis/forms/fields.py
@@ -1,7 +1,6 @@
 from __future__ import unicode_literals
 
 from django import forms
-from django.utils import six
 from django.utils.translation import ugettext_lazy as _
 
 # While this couples the geographic forms to the GEOS library,
@@ -85,7 +84,7 @@ class GeometryField(forms.Field):
         try:
             data = self.to_python(data)
             initial = self.to_python(initial)
-        except ValidationError:
+        except forms.ValidationError:
             return True
 
         # Only do a geographic comparison if both values are available
diff --git a/django/contrib/sessions/tests.py b/django/contrib/sessions/tests.py
index 30814e466b..0b10e14530 100644
--- a/django/contrib/sessions/tests.py
+++ b/django/contrib/sessions/tests.py
@@ -424,10 +424,6 @@ class FileSessionTests(SessionTestsMixin, unittest.TestCase):
         # Make sure the file backend checks for a good storage dir
         self.assertRaises(ImproperlyConfigured, self.backend)
 
-    def test_invalid_key_backslash(self):
-        # This key should be refused and a new session should be created
-        self.assertTrue(self.backend("a\\b\\c").load())
-
     def test_invalid_key_backslash(self):
         # Ensure we don't allow directory-traversal.
         # This is tested directly on _key_to_file, as load() will swallow
diff --git a/django/core/cache/__init__.py b/django/core/cache/__init__.py
index 2721a791fa..4cafeccd2a 100644
--- a/django/core/cache/__init__.py
+++ b/django/core/cache/__init__.py
@@ -85,7 +85,7 @@ def parse_backend_conf(backend, **kwargs):
     else:
         try:
             # Trying to import the given backend, in case it's a dotted path
-            backend_cls = import_by_path(backend)
+            import_by_path(backend)
         except ImproperlyConfigured as e:
             raise InvalidCacheBackendError("Could not find backend '%s': %s" % (
                 backend, e))
diff --git a/django/core/management/commands/loaddata.py b/django/core/management/commands/loaddata.py
index a6e22d9173..20ab486489 100644
--- a/django/core/management/commands/loaddata.py
+++ b/django/core/management/commands/loaddata.py
@@ -6,7 +6,6 @@ import os
 import warnings
 import zipfile
 from optparse import make_option
-import warnings
 
 from django.conf import settings
 from django.core import serializers
diff --git a/django/core/management/sql.py b/django/core/management/sql.py
index 379def27dc..f5e0b7367b 100644
--- a/django/core/management/sql.py
+++ b/django/core/management/sql.py
@@ -9,7 +9,6 @@ from django.conf import settings
 from django.core.management.base import CommandError
 from django.db import models
 from django.db.models import get_models
-from django.utils._os import upath
 
 
 def sql_create(app, style, connection):
diff --git a/django/db/backends/oracle/schema.py b/django/db/backends/oracle/schema.py
index 467d6167fa..1733fc0690 100644
--- a/django/db/backends/oracle/schema.py
+++ b/django/db/backends/oracle/schema.py
@@ -1,12 +1,11 @@
 import copy
-import datetime
-from django.utils import six
+
 from django.db.backends.schema import BaseDatabaseSchemaEditor
 from django.db.utils import DatabaseError
 
 
 class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
-    
+
     sql_create_column = "ALTER TABLE %(table)s ADD %(column)s %(definition)s"
     sql_alter_column_type = "MODIFY %(column)s %(type)s"
     sql_alter_column_null = "MODIFY %(column)s NULL"
@@ -15,7 +14,7 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
     sql_alter_column_no_default = "MODIFY %(column)s DEFAULT NULL"
     sql_delete_column = "ALTER TABLE %(table)s DROP COLUMN %(column)s"
     sql_delete_table = "DROP TABLE %(table)s CASCADE CONSTRAINTS"
-    
+
     def delete_model(self, model):
         # Run superclass action
         super(DatabaseSchemaEditor, self).delete_model(model)
diff --git a/django/db/backends/schema.py b/django/db/backends/schema.py
index 8b4255267c..5f0bf0a28b 100644
--- a/django/db/backends/schema.py
+++ b/django/db/backends/schema.py
@@ -1,6 +1,5 @@
 import hashlib
 import operator
-import sys
 
 from django.db.backends.creation import BaseDatabaseCreation
 from django.db.backends.util import truncate_name
diff --git a/django/forms/formsets.py b/django/forms/formsets.py
index e46a440480..02b07a8604 100644
--- a/django/forms/formsets.py
+++ b/django/forms/formsets.py
@@ -289,7 +289,8 @@ class BaseFormSet(object):
         # We loop over every form.errors here rather than short circuiting on the
         # first failure to make sure validation gets triggered for every form.
         forms_valid = True
-        err = self.errors
+        # This triggers a full clean.
+        self.errors
         for i in range(0, self.total_form_count()):
             form = self.forms[i]
             if self.can_delete:
diff --git a/django/template/defaulttags.py b/django/template/defaulttags.py
index a7af7d7de8..0eae48eb87 100644
--- a/django/template/defaulttags.py
+++ b/django/template/defaulttags.py
@@ -54,7 +54,6 @@ class CsrfTokenNode(Node):
         else:
             # It's very probable that the token is missing because of
             # misconfiguration, so we raise a warning
-            from django.conf import settings
             if settings.DEBUG:
                 warnings.warn("A {% csrf_token %} was used in a template, but the context did not provide the value.  This is usually caused by not using RequestContext.")
             return ''
diff --git a/django/test/client.py b/django/test/client.py
index 4e4a600548..fe7c3131cf 100644
--- a/django/test/client.py
+++ b/django/test/client.py
@@ -91,8 +91,6 @@ class ClientHandler(BaseHandler):
         super(ClientHandler, self).__init__(*args, **kwargs)
 
     def __call__(self, environ):
-        from django.conf import settings
-
         # Set up middleware if needed. We couldn't do this earlier, because
         # settings weren't available.
         if self._request_middleware is None:
diff --git a/django/utils/html.py b/django/utils/html.py
index 76fc23713d..ff3bc60021 100644
--- a/django/utils/html.py
+++ b/django/utils/html.py
@@ -210,7 +210,6 @@ def urlize(text, trim_url_limit=None, nofollow=False, autoescape=False):
     safe_input = isinstance(text, SafeData)
     words = word_split_re.split(force_text(text))
     for i, word in enumerate(words):
-        match = None
         if '.' in word or '@' in word or ':' in word:
             # Deal with punctuation.
             lead, middle, trail = '', word, ''