max / min / smallest float value on Python 2.5

duncan smith buzzard at urubu.freeserve.co.uk
Sun Feb 7 01:52:48 CET 2010


Hello,
       I'm trying to find a clean and reliable way of uncovering 
information about 'extremal' values for floats on versions of Python 
earlier than 2.6 (just 2.5 actually).  I don't want to add a dependence 
on 3rd party modules just for this purpose.  e.g. For the smallest 
positive float I'm using,


import platform
if platform.architecture()[0].startswith('64'):
     TINY = 2.2250738585072014e-308
else:
     TINY = 1.1754943508222875e-38


where I've extracted the values for TINY from numpy in IDLE,


 >>> float(numpy.finfo(numpy.float32).tiny)
1.1754943508222875e-38
 >>> float(numpy.finfo(numpy.float64).tiny)
2.2250738585072014e-308
 >>>


I'm not 100% sure how reliable this will be across platforms.  Any ideas 
about the cleanest, reliable way of uncovering this type of information? 
  (I can always invoke numpy, or use Python 2.6, on my home machine and 
hardcode the retrieved values, but I need the code to run on 2.5 without 
3rd part dependencies.)  Cheers.

Duncan



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