concurrency.py

#!/usr/local/bin/python3
from multiprocessing import Process
from threading import Thread
import time

def f(n):
    for i in range(n):
        i

class Clock:

    def __enter__(self):
        self.start = time.time()

    def __exit__(self, *args, **kwargs):
        self.end = time.time()
        self.elapsed = self.end-self.start
        print(self.elapsed)

if __name__ == '__main__':
    n_runs = 4

    with Clock():
        print('Sequential')
        for i in range(n_runs):
            f(10**8)

    with Clock():
        print('Threading')
        pool = []
        for i in range(n_runs):
            pool.append(Thread(target=f, args=(10**8,)))
            pool[i].start()

        for i in range(n_runs):
            pool[i].join()

    with Clock():
        print('Multiprocessing')
        pool = []
        for i in range(n_runs):
            pool.append(Process(target=f, args=(10**8,)))
            pool[i].start()

        for i in range(n_runs):
            pool[i].join()