This definition of NaN is much better in mentally visualizing all the so called bizarreness of IEEE. This also makes intuitive that no 2 NaN will be equal just as no 2 infinities would be equal. I believe in a hypothesis(of my own creation) that any arithmetic on a data type of NaN would be similar to any set of operations on the set of Infinities.
On Thu, Feb 14, 2019, 12:33 AM Avi Gross <avigr...@verizon.net wrote: > I won't speak for the IEEE but NOT A NUMBER does not tell you what > something > IS. > > If "Hello, World!" is not a number as in an int or a float and we throw > away > the content and simply call it a NaN or something and then we notice that > an > object that is a list of fruits is also not a number so we call it a NaN > too, then should they be equal? > > A NaN is a bit like a black hole. Anything thrown in disappears and that is > about all we know about it. No two black holes are the same even if they > seem to have the same mass, spin and charge. All they share is that we > don't > know what is in them. > > When variable "a" is a Nan then it is sort of a pointer to a concept. The > pointer IS itself but the concepts may not be. > > -----Original Message----- > From: Python-list <python-list-bounces+avigross=verizon....@python.org> On > Behalf Of Grant Edwards > Sent: Wednesday, February 13, 2019 1:03 PM > To: python-list@python.org > Subject: Re: Why float('Nan') == float('Nan') is False > > On 2019-02-13, ast <n...@gmail.com> wrote: > > Hello > > > > >>> float('Nan') == float('Nan') > > False > > If you think that's odd, how about this? > > >>> n = float('nan') > >>> n > nan > >>> n is n > True > >>> n == n > False > >>> > > > Why ? > > IEEE says so. > > -- > Grant Edwards grant.b.edwards Yow! Like I always say > at -- nothing can beat > gmail.com the BRATWURST here in > DUSSELDORF!! > > -- > https://mail.python.org/mailman/listinfo/python-list > > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list