              self.__class__.__name__,
              smart_repr(self.queryset),
              smart_repr(self.field),
              smart_repr(self.date_field)
          ))
  
  
  class UniqueForDateValidator(BaseUniqueForValidator):
      message = _('This field must be unique for the "{date_field}" date.')
  
 
</s> remove         return unicode_to_repr('<%s(queryset=%s, field=%s, date_field=%s)>' % (
 </s> add         return '<%s(queryset=%s, field=%s, date_field=%s)>' % ( </s> remove         ))
 </s> add         ) </s> remove         return unicode_to_repr('<%s(queryset=%s, fields=%s)>' % (
 </s> add         return '<%s(queryset=%s, fields=%s)>' % ( </s> remove class BaseUniqueForValidator(object):
 </s> add class BaseUniqueForValidator: </s> remove class Field(object):
 </s> add class Field:
        )
              self.__class__.__name__,
              smart_repr(self.queryset),
              smart_repr(self.field),
              smart_repr(self.date_field)
        )
  
  
  class UniqueForDateValidator(BaseUniqueForValidator):
      message = _('This field must be unique for the "{date_field}" date.')
  
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/validators.py