Generate Pi from checking if two random numbers are coprime. https://www.youtube.com/watch?v=RZBhSi_PwHU

pi.py

from math import sqrt
from random import randint

try:
    from math import gcd
except:
    from fractions import gcd

ITERATIONS = 1000000
MAX_INT = 1000000000
total = 0

for i in range(ITERATIONS):
    a, b = randint(1, MAX_INT), randint(1, MAX_INT)
    total += gcd(a, b) == 1

print(sqrt(6.0 * ITERATIONS / total))