from google.appengine.ext import db

class Pet(db.Model):
    name = db.StringProperty(required=True)
    type = db.StringProperty(required=True,choices=set(["cat","dog","bird"]))
    birthdate = db.DateProperty()
    weight_in_pounds = db.IntegerProperty()
    spayed_or_neutered = db.BooleanProperty()
    owner = db.UserProperty(required=True)

我想将name的默认值设置为“Unnamed Pet”,因此如果用户不提供,则采用默认值.这可能吗？

PS：我希望这可以在模型类Pet本身中完成