Mercurial > cpython-lru_cache-weakref

annotate Demo/scripts/pi.py @ 4566:6403c94de50d legacy-trunk

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Added safeguard against failure in __del__.
author Guido van Rossum <guido@python.org>
date Wed, 27 Nov 1996 19:39:58 +0000
parents 28948181fb2f
children 73758db2f464
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1 #! /usr/local/bin/python
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2
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3 # Print digits of pi forever.
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4 #
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5 # The algorithm, using Python's 'long' integers ("bignums"), works
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6 # with continued fractions, and was conceived by Lambert Meertens.
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7 #
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8 # See also the ABC Programmer's Handbook, by Geurts, Meertens & Pemberton,
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9 # published by Prentice-Hall (UK) Ltd., 1990.
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10
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11 import sys
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12
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13 def main():
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14 k, a, b, a1, b1 = 2L, 4L, 1L, 12L, 4L
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15 while 1:
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16 # Next approximation
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17 p, q, k = k*k, 2L*k+1L, k+1L
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18 a, b, a1, b1 = a1, b1, p*a+q*a1, p*b+q*b1
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19 # Print common digits
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20 d, d1 = a/b, a1/b1
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21 while d == d1:
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22 output(d)
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23 a, a1 = 10L*(a%b), 10L*(a1%b1)
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24 d, d1 = a/b, a1/b1
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25
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26 def output(d):
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27 # Use write() to avoid spaces between the digits
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28 # Use int(d) to avoid a trailing L after each digit
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29 sys.stdout.write(`int(d)`)
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30 # Flush so the output is seen immediately
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31 sys.stdout.flush()
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32
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33 main()