  from django.core.exceptions import ObjectDoesNotExist
  from django.core.urlresolvers import resolve, get_script_prefix, NoReverseMatch
  from rest_framework.compat import urlparse
  
  
  class RelatedField(Field):
      def __init__(self, **kwargs):
 
</s> remove def get_default_queryset(serializer_class, field_name):
    manager = getattr(serializer_class.opts.model, field_name)
    if hasattr(manager, 'related'):
        # Forward relationships
        return manager.related.model._default_manager.all()
    # Reverse relationships
    return manager.field.rel.to._default_manager.all()


 </s> add  </s> remove         'invalid': _("Time has wrong format. Use one of these formats instead: %s"),
 </s> add         'invalid': _('Time has wrong format. Use one of these formats instead: {format}'), </s> remove         'invalid': _("Datetime has wrong format. Use one of these formats instead: %s"),
 </s> add         'invalid': _('Datetime has wrong format. Use one of these formats instead: {format}'), </s> remove         'invalid': _("Date has wrong format. Use one of these formats instead: %s"),
 </s> add         'invalid': _('Date has wrong format. Use one of these formats instead: {format}'), </s> remove     def get_url(self, obj, view_name, request, format):
        """
        Given an object, return the URL that hyperlinks to the object.

        May raise a `NoReverseMatch` if the `view_name` and `lookup_field`
        attributes are not configured to correctly match the URL conf.
        """
        # Unsaved objects will not yet have a valid URL.
        if obj.pk is None:
            return None

        lookup_value = getattr(obj, self.lookup_field)
        kwargs = {self.lookup_url_kwarg: lookup_value}
        return reverse(view_name, kwargs=kwargs, request=request, format=format)

 </s> add 
from django.db.models.query import QuerySet
  from django.core.exceptions import ObjectDoesNotExist
  from django.core.urlresolvers import resolve, get_script_prefix, NoReverseMatch
from django.db.models.query import QuerySet
  from rest_framework.compat import urlparse
  
  
  class RelatedField(Field):
      def __init__(self, **kwargs):
keep add keep keep keep keep keep
 Clean up relational fields queryset usage 
rest_framework/relations.py