# Source: https://stackoverflow.com/questions/9004789/1000-digits-of-pi-in-python

import time


def make_pi():
    q, r, t, k, m, x = 1, 0, 1, 1, 3, 3
    for j in range(10000):
        if 4 * q + r - t < m * t:
            yield m
            q, r, t, k, m, x = (
                10 * q,
                10 * (r - m * t),
                t,
                k,
                (10 * (3 * q + r)) // t - 10 * m,
                x,
            )
        else:
            q, r, t, k, m, x = (
                q * k,
                (2 * q + r) * x,
                t * x,
                k + 1,
                (q * (7 * k + 2) + r * x) // (t * x),
                x + 2,
            )


t1 = time.time()

pi_array = []
for i in make_pi():
    pi_array.append(str(i))

pi_array = pi_array[:1] + ['.'] + pi_array[1:]
pi_array_str = ''.join(pi_array)

print('PI:', pi_array_str)
print('dT:', time.time() - t1)