Python Mongoengine中带反向删除规则的循环依赖

我有以下相互依赖的模型：

from mongoengine import *

class DocumentA(Document):
    docB = ReferenceField('DocumentB', reverse_delete_rule=CASCADE)

class DocumentB(Document):
    docA = ReferenceField('DocumentA', reverse_delete_rule=CASCADE)

我得到以下错误：

mongoengine.errors.NotRegistered: `DocumentB` has not been registered in the document registry.
            Importing the document class automatically registers it, has it
            been imported?

如果删除第一条

反向删除规则

，此错误将消失：

from mongoengine import *

class DocumentA(Document):
    docB = ReferenceField('DocumentB')

class DocumentB(Document):
    docA = ReferenceField('DocumentA', reverse_delete_rule=CASCADE)

很好

有没有办法保持

反向删除规则

？

来自：

用于注册删除规则的替代语法（在 实现双向删除规则）

因此，您的代码变成：

from mongoengine import *

class DocumentA(Document):
    docB = ReferenceField('DocumentB')

class DocumentB(Document):
    docA = ReferenceField('DocumentA', reverse_delete_rule=CASCADE)

DocumentB.register_delete_rule(DocumentA, 'docB', CASCADE)

from mongoengine import *

class DocumentA(Document):
    docB = ReferenceField('DocumentB')

class DocumentB(Document):
    docA = ReferenceField('DocumentA', reverse_delete_rule=CASCADE)

DocumentB.register_delete_rule(DocumentA, 'docB', CASCADE)