1 #! /usr/bin/env python 2 3 # Print digits of pi forever. 4 # 5 # The algorithm, using Python's 'long' integers ("bignums"), works 6 # with continued fractions, and was conceived by Lambert Meertens. 7 # 8 # See also the ABC Programmer's Handbook, by Geurts, Meertens & Pemberton, 9 # published by Prentice-Hall (UK) Ltd., 1990. 10 11 import sys 12 13 def main(): 14 k, a, b, a1, b1 = 2, 4, 1, 12, 4 15 while True: 16 # Next approximation 17 p, q, k = k*k, 2*k+1, k+1 18 a, b, a1, b1 = a1, b1, p*a+q*a1, p*b+q*b1 19 # Print common digits 20 d, d1 = a//b, a1//b1 21 while d == d1: 22 output(d) 23 a, a1 = 10*(a%b), 10*(a1%b1) 24 d, d1 = a//b, a1//b1 25 26 def output(d): 27 # Use write() to avoid spaces between the digits 28 sys.stdout.write(str(d)) 29 # Flush so the output is seen immediately 30 sys.stdout.flush() 31 32 if __name__ == "__main__": 33 main() 34
