[Python-Dev] Unicode minus sign in numeric conversions

[R. David Murray]

On Sun, 09 Jun 2013 01:39:59 +0100, MRAB <python at mrabarnett.plus.com> wrote:
> On 08/06/2013 23:30, Guido van Rossum wrote:
> > [Diverting to python-ideas, since this isn't as clear-cut as you think.]
> >
> > Why exactly is that expected behavior? What's the use case? (Surely
> > you don't have a keyboard that generates \u2212 when you hit the minus
> > key? :-)
> >
> > Is there a Unicode standard for parsing numbers? IIRC there are a
> > variety of other things marked as "digits" in the Unicode standard --
> > do we do anything with those? If we do anything we should be
> > consistent. For now, I think we *are* consistent -- we only support
> > the ASCII representation of numbers. (And that's the only
> > representation we generate as output as well -- think about symmetry
> > too.)
> >
> We already recognise at least some of the digits:
> 
>  >>> float("\N{ARABIC-INDIC DIGIT ONE}")
> 1.0
> 
> (I haven't check all of them!)
> 
> > This page scares me: http://en.wikipedia.org/wiki/Numerals_in_Unicode

http://bugs.python.org/issue6632 contains a bunch of good information 
relevant to this discussion.  It looks like the argument there was
that there is no standard for the signs, therefore we should not
support them.

As Guido said, the issue is non-trivial.

--David