pi.py

import math
import random
import sys

def main():
    num = int(sys.argv[1])
    points_in = 0
    for _ in range(num):
        px, py = random.random() * 2 - 1, random.random() * 2 - 1
        if (px**2 + py**2) <= 1:
            points_in += 1

    pi_approx = 4.0 * points_in / num
    print('Approx = {}'.format(pi_approx))

if __name__ == '__main__':
    main()