class Settings(ndb.Model):
    name = ndb.StringProperty()
value = ndb.StringProperty()

@staticmethod
def get(name):
    NOT_SET_VALUE = 'NOT SET'
retval = Settings.query(Settings.name == name).get()
if not retval:
    retval = Settings()
retval.name = name
retval.value = NOT_SET_VALUE
retval.put()
if retval.value == NOT_SET_VALUE:
    raise Exception(('Setting %s not found in the database. A placeholder ' +
        'record has been created. Go to the Developers Console for your app ' +
        'in App Engine, look up the Settings record with name=%s and enter ' +
        "its value in that record's value field.") % (name, name))
return retval.value
хранение настроек приложения в Google App Engine