How to get around the pickling error of python multiprocessing without being in the top-level?

Question

I\'ve researched this question multiple times, but haven\'t found a workaround that either works in my case, or one that I understand, so please bear with me.

Basically

Answer 1

How about just taking the embedded function out?

This seems to me the clearest solution (since you didn't give your expected output, I had to guess):

$ cat /tmp/tmp.py
import multiprocessing

def calculate(x):
    # here is where I would take this input x (and maybe a couple more inputs)
    # and build a larger library of variables that I use further down the line

    pool = multiprocessing.Pool(3)
    _lst = [(x, y) for x in (x,) for y in range(3)]
    final= pool.map(domath, _lst)
    print(final)

def domath(l):
    return l[0] * l[1]

calculate(2)

$ python /tmp/tmp.py
[0, 2, 4]

$