  from django.core.exceptions import PermissionDenied
  from django.http import Http404
  from django.utils import six
  from django.utils.encoding import smart_text
  from django.utils.translation import ugettext_lazy as _
  from django.views.decorators.csrf import csrf_exempt
  from rest_framework import status, exceptions
  from rest_framework.compat import HttpResponseBase, View, set_rollback
  from rest_framework.request import Request
  from rest_framework.response import Response
 
</s> remove from rest_framework.compat import HttpResponseBase, View, set_rollback
 </s> add  </s> remove from django.core.exceptions import PermissionDenied
from django.http import Http404
 </s> add import inspect
import warnings

from django.core.exceptions import PermissionDenied
  from django.core.exceptions import PermissionDenied
  from django.http import Http404
  from django.utils import six
  from django.utils.encoding import smart_text
from django.core.exceptions import PermissionDenied
  from django.views.decorators.csrf import csrf_exempt
  from rest_framework import status, exceptions
  from rest_framework.compat import HttpResponseBase, View, set_rollback
  from rest_framework.request import Request
  from rest_framework.response import Response
keep keep keep keep replace keep keep keep keep keep
 Cleanup import following PEP 8 style guide 
rest_framework/views.py