Can Python multiprocessing process be launched from OTHER than __main__?

Question

I am writing a framework in Python 3.8 on Debian that will launch some multiprocessing processes. I want the configuration and launching of the processes to be done in functions OTHER than the main . The main file will be written by the end user of the framework and they should not need to know about these processes. Hence I tried to put the code that configures and launches the processes in helper functions or class methods that the main will call.

What I'm finding is as soon as the launcher function / method exits the processes die. This is even though the launcher functions / methods run (I think) in the same process as main which is still running. I have put a long time.sleep in the launcher functions / methods right before they exit and it seems the processes are alive for that long.

I tried setting the 'daemon' flag but that doesn't seem to solve it. If this is truly a limitation of multiprocessing I can instruct the users of my framework to always put some boiler-plate launcher code in their file, but it seems clunky. All help is appreciated!

Answer 1

The function that launches the processes was returning only the processes to main and NOT managed queues that the processes were using. I changed to return a dict with the processes AND the managed queues and everything works. This is even though main does NOT use the queues.