#! /usr/bin/env python # Print digits of pi forever. # # The algorithm, using Python's 'long' integers ("bignums"), works # with continued fractions, and was conceived by Lambert Meertens. # # See also the ABC Programmer's Handbook, by Geurts, Meertens & Pemberton, # published by Prentice-Hall (UK) Ltd., 1990. import sys def main(): k, a, b, a1, b1 = 2L, 4L, 1L, 12L, 4L while 1: # Next approximation p, q, k = k*k, 2L*k+1L, k+1L a, b, a1, b1 = a1, b1, p*a+q*a1, p*b+q*b1 # Print common digits d, d1 = a/b, a1/b1 while d == d1: output(d) a, a1 = 10L*(a%b), 10L*(a1%b1) d, d1 = a/b, a1/b1 def output(d): # Use write() to avoid spaces between the digits # Use int(d) to avoid a trailing L after each digit sys.stdout.write(`int(d)`) # Flush so the output is seen immediately sys.stdout.flush() main()