使用PickleProperty在GAE中存储字典

时间:2012-05-31 23:38:59

标签: python google-app-engine webapp2

我有一个python字典,我试图通过pickle属性存储在GAE Gql数据存储区中。

我试着按照这个问题回答, Store a list of dictionaries in GAE

但它不适用于我的代码。我收到错误,我的列表出现问题

我设置了pickle属性和数据模型类,如下所示,

class PickleProperty(db.Property):
    def get_value_for_datastore(self, model_instance):
        value = getattr(model_instance, self.name, None)
        return pickle.dumps(value)

    def make_value_from_datastore(self, value):
        return pickle.mloads(value)

class MDB(db.Model):
    Name = db.StringProperty(required=True)
    Times = PickleProperty()
    created = db.DateTimeProperty(auto_now_add = True)

我的代码中有一个函数,它插入数据并将其读出

def m_time_manage(m=""):

    if not m:
        r = db.GqlQuery("select * from MDB")
    else:
        #find specific masjid requested
        r = db.GqlQuery("select * from MDB where Name = %s" % (s))

    #if masjid time data doesn't exist in db throw in placeholders...
    if r is None:
        times = {}
        times['a'] = "8:49"
        times['b'] = "10:19"

        times_entry = MDB(Name="abc",Times=times)
        times_entry.put()

    r = db.GqlQuery("select * from MasjidDB")
    return (r[0].Name, r[0].Times)

在我的get函数中,我按如下方式调用m_time_manage()ftn,

(mName, times) = m_time_manage()
        self.write(times)

我得到这个错误,那就是pickle.loads和文件结束错误......完整的错误是但是我不确定如何在python中存储字典,

 line 31, in make_value_from_datastore
    return pickle.loads(value)
  File "/usr/lib/python2.7/pickle.py", line 1382, in loads
    return Unpickler(file).load()
  File "/usr/lib/python2.7/pickle.py", line 858, in load
    dispatch[key](self)
  File "/usr/lib/python2.7/pickle.py", line 880, in load_eof
    raise EOFError

感谢您提前提供任何帮助

1 个答案:

答案 0 :(得分:6)

我建议切换到NDB并使用其内置的PickleProperty。见https://developers.google.com/appengine/docs/python/ndb/properties