基于模型的类的继承，Python

我目前有一个使用以下代码的项目：

类.py

class Session(Conference, ndb.Model):
    ''' Session - A Session object '''
    # The session's name
    sessionName     = ndb.StringProperty()
    # Highlights of the session
    highlights      = ndb.StringProperty(repeated = True)
    # The session's speaker
    speaker         = ndb.StringProperty()
    # How long the session will last
    duration        = ndb.TimeProperty()
    # The type of session (Workshop, lecture, etc...); Default 'Not Specified'
    typeOfSession   = ndb.StringProperty(default = 'NOT_SPECIFIED')
    # Date the session takes place on
    date            = ndb.DateProperty()
    # The time the session starts
    startTime       = ndb.TimeProperty()
    # The Conference this Session is at
    parentConf      = Conference

class Conference(ndb.Model):
    '''Conference -- Conference object'''
    name            = ndb.StringProperty(required=True)
    description     = ndb.StringProperty()
    organizerUserId = ndb.StringProperty()
    topics          = ndb.StringProperty(repeated=True)
    city            = ndb.StringProperty()
    startDate       = ndb.DateProperty()
    month           = ndb.IntegerProperty() # TODO: do we need for indexing like Java?
    endDate         = ndb.DateProperty()
    maxAttendees    = ndb.IntegerProperty()
    seatsAvailable  = ndb.IntegerProperty()

我正试图调用代码 conf=会议（**数据）.put（） 变量=会话（conf，**数据）.put（）

其中conf是一个会议对象（我已经验证了这一点） **data是一个输入数据数组，它可以工作（我已经测试过了） 但是当我调用这个函数时，我得到了一个错误

“TypeError:模型构造函数不接受位置参数。”

经过一些搜索，我发现这是由于我试图重载ndb.Model的构造函数，我被告知我不应该这样做

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所以我的问题是，我将如何管理这种继承，其中Session是Conference的子对象，但在构建过程中仍然使用ndb.Model数据？谢谢你的时间

将PolyModel用于数据存储继承->

以下是一个例子：

from google.appengine.ext import ndb
from google.appengine.ext.ndb import polymodel

class Contact(polymodel.PolyModel):
  phone_number = ndb.PhoneNumberProperty()
  address = ndb.PostalAddressProperty()

class Person(Contact):
  first_name = ndb.StringProperty()
  last_name = ndb.StringProperty()
  mobile_number = ndb.PhoneNumberProperty()

class Company(Contact):
  name = ndb.StringProperty()
  fax_number = ndb.PhoneNumberProperty()

p = Person(phone_number='1-206-555-9234',
           address='123 First Ave., Seattle, WA, 98101',
           first_name='Alfred',
           last_name='Smith',
           mobile_number='1-206-555-0117')
p.put()

c = Company(phone_number='1-503-555-9123',
            address='P.O. Box 98765, Salem, OR, 97301',
            name='Data Solutions, LLC',
            fax_number='1-503-555-6622')
c.put()

for contact in Contact.query():
  print 'Phone: %s\nAddress: %s\n\n' % (contact.phone_number, contact.address)

---

将PolyModel用于数据存储继承->

以下是一个例子：

from google.appengine.ext import ndb
from google.appengine.ext.ndb import polymodel

class Contact(polymodel.PolyModel):
  phone_number = ndb.PhoneNumberProperty()
  address = ndb.PostalAddressProperty()

class Person(Contact):
  first_name = ndb.StringProperty()
  last_name = ndb.StringProperty()
  mobile_number = ndb.PhoneNumberProperty()

class Company(Contact):
  name = ndb.StringProperty()
  fax_number = ndb.PhoneNumberProperty()

p = Person(phone_number='1-206-555-9234',
           address='123 First Ave., Seattle, WA, 98101',
           first_name='Alfred',
           last_name='Smith',
           mobile_number='1-206-555-0117')
p.put()

c = Company(phone_number='1-503-555-9123',
            address='P.O. Box 98765, Salem, OR, 97301',
            name='Data Solutions, LLC',
            fax_number='1-503-555-6622')
c.put()

for contact in Contact.query():
  print 'Phone: %s\nAddress: %s\n\n' % (contact.phone_number, contact.address)