mirror of https://github.com/python/cpython.git
35 lines
943 B
Python
35 lines
943 B
Python
|
#! /usr/local/bin/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
|
||
|
|
from mpz import mpz
|
||
|
|
|
||
|
|
def main():
|
||
|
|
mpzone, mpztwo, mpzten = mpz(1), mpz(2), mpz(10)
|
||
|
|
k, a, b, a1, b1 = mpz(2), mpz(4), mpz(1), mpz(12), mpz(4)
|
||
|
|
while 1:
|
||
|
|
# Next approximation
|
||
|
|
p, q, k = k*k, mpztwo*k+mpzone, k+mpzone
|
||
|
|
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 = mpzten*(a%b), mpzten*(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()
|