创建从weakref到pydantic的模型

Question

有可能创建一个pydantic模型的weakref吗

from pydantic import BaseModel
from uuid import UUID

class JEdgeModel(BaseModel):
    uid: UUID
    startSocket: UUID
    destnSocket: UUID

a = JEdgeModel(uid='abd6fc3f882544f5b75661c92fccbd0d', startSocket='abd6fc3f882544f5b75661c92fccbd0d', destnSocket='abd6fc3f882544f5b75661c92fccbd0d')

wk = weakref.ref(a)

我得到以下错误： cannot create weak reference to 'JEdgeModel' object

有没有办法达到同样的效果

Answer 1

从documentation

Without a weakref variable for each instance, classes defining slots do not support weak references to its instances. If weak reference support is needed, then add 'weakref' to the sequence of strings in the slots declaration.

因此，只需将__weakref__添加到模型中的__slot__

class JEdgeModel(BaseModel):
    __slots__ = ['__weakref__']
    uid: UUID
    startSocket: UUID
    destnSocket: UUID

a = JEdgeModel(
    uid='abd6fc3f882544f5b75661c92fccbd0d',
    startSocket='abd6fc3f882544f5b75661c92fccbd0d',
    destnSocket='abd6fc3f882544f5b75661c92fccbd0d',
)

wk = weakref.ref(a)