[Python-Dev] Not-a-Number

[Steven D'Aprano]

Greg Ewing wrote:
> Taking a step back from all this, why does Python allow
> NaNs to arise from computations *at all*?

The real question should be, why does Python treat all NANs as 
signalling NANs instead of quiet NANs? I don't believe this helps anyone.

> +Inf and -Inf are arguably useful elements of the algebra,
> yet Python insists on raising an exception for 1.0./0.0
> instead of returning an infinity.

I would argue that Python is wrong to do so.

As I've mentioned a couple of times now, 20 years ago Apple felt that 
NANs and INFs weren't too complicated for non-programmers using 
Hypercard. There's no sign that Apple were wrong to expose NANs and INFs 
to users, no flood of Hypercard users confused by NAN inequality.



-- 
Steven