Multiprocessing with spawn and environment variables

Python Help
1

Hey folks,

When using spawn as the multiprocessing start method, is there an easy way to persist the environment variables (as a snapshot) from os.environ into the new processes?

We have an old case where fork was used and this all worked out, but now with spawn we lose the environment variables changed in the parent python process when the child starts up. I’m sure I could save them and pass them as a function parameter or something but that seems like something that someone may have already solved for.

Thanks!

2

Answering my own question:

Something else is probably wrong. The environment variables should pass on their own. Example:

from multiprocessing import Pool, get_start_method
import os

def print_test():
    print(str(os.environ.get('TEST')))

if __name__ == '__main__':
    print(get_start_method())

    os.environ['TEST'] = 'hello world'
    with Pool() as p:
        p.apply_async(print_test).get()

    os.environ['TEST'] = 'hello again'
    with Pool() as p:
        p.apply_async(print_test).get()

gets us:

spawn
hello world
hello again

So something else is afoot.