jsff_python_mp.py

#!/usr/bin/env python3

from itertools import count
from math import sqrt
from concurrent.futures import ProcessPoolExecutor

def factory (x):
    f = lambda k: 1.0/(k*(k+x))
    return (f(k) for k in range(1, 1000000))

def psi (x):
    return sum(factory(x))

with ProcessPoolExecutor(max_workers=4) as executor:
    records = []
    for x in (0.0, 0.5, 1.0, sqrt(2), 10.0, 100.0, 300.0):
        worker = executor.submit(psi, x)
        records.append((x, worker))

for x, future in records:
    print("%6.2f , %16.12e" % (x, future.result()))