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Date: Thu, 23 Feb 2012 05:13:17 +1100
Subject: Python math is off by .000000000000045
From: Alec Taylor <alec.taylor6@gmail.com>
To: "comp.lang.python" <python-list@python.org>
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Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:20689

Simple mathematical problem, + and - only:

>>> 1800.00-1041.00-555.74+530.74-794.95
-60.950000000000045

That's wrong.

Proof
http://www.wolframalpha.com/input/?i=1800.00-1041.00-555.74%2B530.74-794.95
-60.95 aka (-(1219/20))

Is there a reason Python math is only approximated? - Or is this a bug?

Thanks for all info,

Alec Taylor