/Demo/scripts/pi.py
http://unladen-swallow.googlecode.com/ · Python · 34 lines · 16 code · 5 blank · 13 comment · 3 complexity · cd3cc9f0ba4ac6d14dc42c18e9287ac7 MD5 · raw file
- #! /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 str() to avoid the 'L'
- sys.stdout.write(str(d))
- # Flush so the output is seen immediately
- sys.stdout.flush()
- if __name__ == "__main__":
- main()