mypy: error: Module "multiprocessing.managers" has no attribute "EventProxy" [at-CodePudding

I have a method which takes a multiprocessing.Manager().Event(), for the purposes of gracefully stopping my app.

When I run mypy against it, it complains that it's not a valid type:

error: Module "multiprocessing.managers" has no attribute "EventProxy" [attr-defined]

Code:

from multiprocessing.managers import EventProxy

class App:
    def run(self, stop_event: EventProxy):
        ...

with Manager() as manager:
    stop_event = manager.Event()
    a = App()
    a.run(stop_event)

I used the type EventProxy because when I checked the type() of the multiprocessing.Manager().Event() it said it was a multiprocessing.managers.EventProxy.

How can I type hint this method so that mypy won't complain?

Versions:

Python          3.9.14
mypy            0.991
mypy-extensions 0.4.3

CodePudding user response：

From the docs: multiprocessing.Manager() Returns a started SyncManager object.

If we check the docs for SyncManager.Event we see that it returns threading.Event.

So in summary:

from multiprocessing import Manager
from threading import Event

class App:
    def run(self, stop_event: Event) -> None:
        print('Hello')

with Manager() as manager:
    stop_event = manager.Event()
    a = App()
    a.run(stop_event)