mirror of https://github.com/python/cpython
34 lines
832 B
Python
Executable File
34 lines
832 B
Python
Executable File
#! /usr/local/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()
|