diff --git a/graphene/contrib/django/debug/middleware.py b/graphene/contrib/django/debug/middleware.py
index adf551ad..01b09e7b 100644
--- a/graphene/contrib/django/debug/middleware.py
+++ b/graphene/contrib/django/debug/middleware.py
@@ -1,8 +1,6 @@
 from promise import Promise
 from django.db import connections
 
-from ....core.schema import GraphQLSchema
-from ....core.types import Field
 from .sql.tracking import unwrap_cursor, wrap_cursor
 from .types import DjangoDebug
 
@@ -47,8 +45,10 @@ class DjangoDebugMiddleware(object):
                 raise Exception('DjangoDebug cannot be executed in None contexts')
             try:
                 context.django_debug = DjangoDebugContext()
-            except Exception, e:
-                raise Exception('DjangoDebug need the context to be writable, context received: {}.'.format(context.__class__.__name__))
+            except Exception:
+                raise Exception('DjangoDebug need the context to be writable, context received: {}.'.format(
+                    context.__class__.__name__
+                ))
         if info.schema.graphene_schema.T(DjangoDebug) == info.return_type:
             return context.django_debug.get_debug_promise()
         promise = next(root, args, context, info)
diff --git a/graphene/contrib/django/debug/sql/tracking.py b/graphene/contrib/django/debug/sql/tracking.py
index ab31dbe5..c636646e 100644
--- a/graphene/contrib/django/debug/sql/tracking.py
+++ b/graphene/contrib/django/debug/sql/tracking.py
@@ -10,6 +10,7 @@ from django.utils.encoding import force_text
 
 from .types import DjangoDebugSQL, DjangoDebugPostgreSQL
 
+
 class SQLQueryTriggered(Exception):
     """Thrown when template panel triggers a query"""
 
diff --git a/graphene/core/types/field.py b/graphene/core/types/field.py
index e7a36f84..7203b3c5 100644
--- a/graphene/core/types/field.py
+++ b/graphene/core/types/field.py
@@ -1,5 +1,5 @@
 from collections import OrderedDict
-from functools import wraps, partial
+from functools import wraps
 
 import six
 from graphql.type import GraphQLField, GraphQLInputObjectField