是否可以通过对象的字典更新Google App Engine数据存储中的条目?

class SourceUpdate(webapp.RequestHandler):
  def post(self):
    id = int(self.request.get('id'))
    source = Source.get_by_id(id)
    for property in self.request.arguments():
      if property != 'id':
        source.__dict__[property] = self.request.get(property)
    source.put()
    self.redirect('/source')

顺便提一下

class Source(db.Model):
  #some string properties