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Date: Fri, 3 Jun 2011 14:35:52 +1000
Subject: Re: float("nan") in set or as key
From: Chris Angelico <rosuav@gmail.com>
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Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:6914

On Fri, Jun 3, 2011 at 2:23 PM, Steven D'Aprano
<steve+comp.lang.python@pearwood.info> wrote:
>> You can't get a valid result from data produced by an invalid
>> computation. Garbage in, garbage out.
>
> Of course you can. Here's a trivial example:
>
> def f(x):
> =A0 =A0return 1
>

If your incoming x is garbage, your outgoing 1 is also garbage. Later
on, you can use 'isgarbage(x)' to find out whether anything went
wrong. You can also use 'isinsane(self)', which is defined as follows:

class Programmer:
  def isinsane(self):
    return True if float("nan")=3D=3Dfloat("nan") else True

Chris Angelico