Classes with `cached_property` can't be cloudpickled

描述

from functools import cached_property
import pickle
import cloudpickle


class MyExample:
    def __init__(self, foo):
        self.foo = foo

    @cached_property
    def bar(self) -> int:
        return self.foo * 3


example = MyExample(2)
pickle.dumps(example)      # works
cloudpickle.dumps(example) # crashes

贡献者指南

技术栈

python

领域

data

议题类型

bug

难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。

3

预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。

1-3 hours

活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。

stale

清晰度议题是否清楚说明期望改动、验收标准和下一步。

clear

前置要求

Pythonbasics of serialization

新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。

60

研究方向

Examine how cloudpickle handles descriptors, specifically `cached property`. The error indicates that `cached property` stores a lock that is not picklable. Look at the ` reduce ` or ` getstate ` methods of cloudpickle to see if it has special handling for `cached property`. A possible fix is to exclude the lock from pickling or to implement ` getstate ` for the class. Check the cloudpickle source code in `cloudpickle/cloudpickle.py` for the relevant sections.