今天封楼被困公司，研究了一下 ProcessPoolExecutor，发现了一个 Python 的 Bug，分享给各位，网上似乎没解决方案

[0x0208v0]

用的 python3.7.13 。报错信息如下兄弟们：

很奇怪为什么不能 raise key-value 格式的自定义错误 ，

要是改成 raise MyError( 1, 'desc') 就没问题了，这是不是 python 的 bug?

# 这是代码，直接，可以运行
from concurrent.futures.process import ProcessPoolExecutor


class MyError(Exception):
    def __init__(self, code: int, desc: str):
        self.code = code
        self.desc = desc


def foo(i, j):
    print(i, j)
    raise MyError(code=1, desc='desc')


def main():
    with ProcessPoolExecutor(3) as executor:
        f = executor.submit(foo, 1, 11)
        e = f.exception()
        print(e)

        f.result()


if __name__ == '__main__':
    main()

下面是输出结果：

1 11
A process in the process pool was terminated abruptly while the future was running or pending.
concurrent.futures.process._RemoteTraceback: 
'''
Traceback (most recent call last):
  File "/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/process.py", line 367, in _queue_management_worker
    result_item = result_reader.recv()
  File "/Python.framework/Versions/3.7/lib/python3.7/multiprocessing/connection.py", line 251, in recv
    return _ForkingPickler.loads(buf.getbuffer())
TypeError: __init__() missing 2 required positional arguments: 'code' and 'desc'
'''

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/v2exblog/demo/aaa.py", line 25, in <module>
    main()
  File "/Users/v2exblog/demo/aaa.py", line 21, in main
    f.result()
  File "/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/_base.py", line 428, in result
    return self.__get_result()
  File "/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
concurrent.futures.process.BrokenProcessPool: A process in the process pool was terminated abruptly while the future was running or pending.

[thinkershare]

封送反序列化的问题, 问题出在 raise 这里, 使用命名参数构造的对象无法按照预期方式反序列化, 错误对象都是构建成功了的.

[thinkershare]

新版本的 python 没啥问题, 已经修复了

[julyclyde]

required positional arguments

它认为__init__里边那俩是位置参数？