Michael> What's the best way to portably generate binary floating point
Michael> infinity and NaNs?
I take it this isn't portable even though it works on Mac, Linux and Solaris
across a number of different Python versions and a couple GCC versions:
% python
Python 2.4.2 (#1, Feb 23 2006, 12:48:31)
[GCC 3.4.1] on sunos5
Type "help", "copyright", "credits" or "license" for more information.
>>> import struct
>>> struct.pack("f", float("NaN"))
'\xff\xff\xff\x7f'
>>> struct.pack("f", float("Inf"))
'\x00\x00\x80\x7f'
$ python
Python 2.5 (release25-maint:53536, Jan 23 2007, 18:15:37)
[GCC 3.4.6 20060404 (Red Hat 3.4.6-3)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import struct
>>> struct.pack("f", float("NaN"))
'\x00\x00\xc0\x7f'
>>> struct.pack("f", float("Inf"))
'\x00\x00\x80\x7f'
% python
Python 2.6a0 (trunk:54264M, Mar 10 2007, 15:19:48)
[GCC 4.0.1 (Apple Computer, Inc. build 5367)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import struct
>>> struct.pack("f", float("Inf"))
'\x7f\x80\x00\x00'
>>> struct.pack("f", float("NaN"))
'\x7f\xc0\x00\x00'
(Note the absence of a demonstration on Windows.) Can't the above be
blessed as the One True Way and wormed around in floatmodule.c for those
platforms where float'ing "NaN" or "Inf" doesn't currently work?
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