Simple multiprocessing example in Python

multi.py

"""A simple example of multiprocessing for a CPU-bound task in Python.

Adapted from https://www.toptal.com/python/beginners-guide-to-concurrency-and-parallelism-in-python
"""
from multiprocessing.pool import Pool
import time


def fib(n):
    """A (contrived) example of a CPU-intensive function that you may want to parallelize."""
    if n < 3:
        return 1
    else:
        return fib(n-1) + fib(n-2)

def fib_and_finish(n):
    r = fib(n)
    print(' Finished!')
    return r


if __name__ == '__main__':
    print('Doing the calculations sequentially')
    ts = time.time()
    for _ in range(4):
        fib_and_finish(34)
    te = time.time()
    print('Took {:.3}s'.format(te - ts))


    print('\nDoing the calculations in parallel')
    ts = time.time()
    with Pool(4) as p:
        p.map(fib_and_finish, [34, 34, 34, 34])
    te = time.time()
    print('Took {:.3}s'.format(te - ts))