              '%s(%s)' % (self.__class__.__name__, unicode_repr(self.default))
          )
  
  
  class CurrentUserDefault(object):
      def set_context(self, serializer_field):
          self.user = serializer_field.context['request'].user
  
      def __call__(self):
          return self.user
 
</s> remove         return unicode_to_repr(
            '%s(%s)' % (self.__class__.__name__, unicode_repr(self.default))
        )
 </s> add         return '%s(%s)' % (self.__class__.__name__, repr(self.default)) </s> remove         return unicode_to_repr('%s()' % self.__class__.__name__)
 </s> add         return '%s()' % self.__class__.__name__ </s> remove         ))
 </s> add         ) </s> remove         ))
 </s> add         ) </s> remove class MockQueryset(object):
 </s> add class MockQueryset:
class CurrentUserDefault:
              '%s(%s)' % (self.__class__.__name__, unicode_repr(self.default))
          )
  
  
class CurrentUserDefault:
      def set_context(self, serializer_field):
          self.user = serializer_field.context['request'].user
  
      def __call__(self):
          return self.user
keep keep keep keep replace keep keep keep keep keep
 Dropped Python 2 compatibility. (#6615)

Thanks to Jon Dufresne (@jdufresne) for review.

Co-authored-by: Asif Saif Uddin <auvipy@gmail.com>
Co-authored-by: Rizwan Mansuri <Rizwan@webbyfox.com> 
rest_framework/fields.py