  
  from django.core.exceptions import ImproperlyConfigured
  from django.db import models
  from django.utils import six
  from rest_framework.compat import django_filters, guardian, get_model_name
  from rest_framework.settings import api_settings
  from functools import reduce
  import operator
  
  FilterSet = django_filters and django_filters.FilterSet or None
 
</s> remove from functools import reduce
import operator
 </s> add from rest_framework.compat import django_filters, guardian, get_model_name
 </s> remove from django.core.exceptions import ImproperlyConfigured
from django.db import models
 </s> add import operator
from functools import reduce
 </s> remove from django.core.exceptions import ImproperlyConfigured
from django.db import models
 </s> add 
from django.db import models
from django.core.exceptions import ImproperlyConfigured

  
  from django.core.exceptions import ImproperlyConfigured
  from django.db import models
  from django.utils import six
from django.db import models
from django.core.exceptions import ImproperlyConfigured

  from rest_framework.settings import api_settings
  from functools import reduce
  import operator
  
  FilterSet = django_filters and django_filters.FilterSet or None
keep keep keep keep replace keep keep keep keep keep
 Cleanup import following PEP 8 style guide 
rest_framework/filters.py