#!/usr/bin/env python
     # encoding: utf-8
     #
     # Copyright (c) 2010 Doug Hellmann.  All rights reserved.
     #
     """Testing for not-a-number.
     """
     #end_pymotw_header
     
     import math
     
     x = (10.0 ** 200) * (10.0 ** 200)
     y = x/x
     
     print 'x =', x
     print 'isnan(x) =', math.isnan(x)
     print 'y = x / x =', x/x
     print 'y == nan =', y == float('nan')
     print 'isnan(y) =', math.isnan(y)