code: def save_attrgetter(self, obj):
          
          class Dummy(object):
              def __init__(self, attrs, index=None):
                  self.attrs = attrs
                  self.index = index
              def __getattribute__(self, item):
                  attrs = object.__getattribute__(self, "attrs")
                  index = object.__getattribute__(self, "index")
                  if index is None:
                      index = len(attrs)
                      attrs.append(item)
                  else:
                      attrs[index] = ".".join([attrs[index], item])
                  return type(self)(attrs, index)
          attrs = []
          obj(Dummy(attrs))
          return self.save_reduce(operator.attrgetter, tuple(attrs))
docs: attrgetter serializer