# Copyright (c) 2008 the authors listed at the following URL, and/or# the authors of referenced articles or incorporated external code:# http://en.literateprograms.org/Pi_with_Machin's_formula_(Python)?action=history&offset=20071208004422# # Permission is hereby granted, free of charge, to any person obtaining# a copy of this software and associated documentation files (the# "Software"), to deal in the Software without restriction, including# without limitation the rights to use, copy, modify, merge, publish,# distribute, sublicense, and/or sell copies of the Software, and to# permit persons to whom the Software is furnished to do so, subject to# the following conditions:# # The above copyright notice and this permission notice shall be# included in all copies or substantial portions of the Software.# # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.# # Retrieved from: http://en.literateprograms.org/Pi_with_Machin's_formula_(Python)?oldid=11786import sysdef arccot(x, unity): sum = xpower = unity // x n = 3 sign = -1 while 1: xpower = xpower // (x*x) term = xpower // n if not term: break sum += sign * term sign = -sign n += 2 return sumdef pi(digits): unity = 10**(digits + 10) pi = 4 * (4*arccot(5, unity) - arccot(239, unity)) return pi // 10**10### MAIN ###try: n = int (sys.argv[1])except: print "Please give me the number of digits to calculate" sys.exit (1)print "Calculating PI to %d digits." % n pi (n)print