pi is a Python script that computes each digit of the value of pi. As long as this script runs it continues to generate digits. As a matter of full disclosure, I did not write this. I am posting it here as a means of preserving the algorithm and making it available to others.

pi.py

import sys

def calcPi():
    q, r, t, k, n, l = 1, 0, 1, 1, 3, 3
    while True:
        if 4*q+r-t < n*t:
            yield n
            nr = 10*(r-n*t)
            n  = ((10*(3*q+r))//t)-10*n
            q  *= 10
            r  = nr
        else:
            nr = (2*q+r)*l
            nn = (q*(7*k)+2+(r*l))//(t*l)
            q  *= k
            t  *= l
            l  += 2
            k += 1
            n  = nn
            r  = nr
 
pi_digits = calcPi()
i = 0
for d in pi_digits:
    sys.stdout.write(str(d))
    i += 1
    if i == 50:
        print("")
        i = 0
        

how does this even work