[Python-Dev] unicodedata.numeric (was RE: stupid floating point question...)

[M.-A. Lemburg]

Fredrik Lundh wrote:
> 
> tim wrote:
> > > But really, I don't suspect that anyone is going to do serious
> > > character to number conversion on these esoteric characters. Plain
> > > old digits will do just as they always have ...
> >
> > Which is why I have to wonder whether there's *any* value in exposing the
> > numeric-value property beyond regular old digits.
> 
> the unicode database has three fields dealing with the numeric
> value: decimal digit value (integer), digit value (integer), and
> numeric value (integer *or* rational):
> 
>     "This is a numeric field. If the character has the numeric
>     property, as specified in Chapter 4 of the Unicode Standard,
>     the value of that character is represented with an integer or
>     rational number in this field."
> 
> here's today's proposal: let's claim that it's a bug to return a float
> from "numeric", and change it to return a string instead.

Hmm, how about making the return format an option ?

unicodedata.numeric(char, format=('float' (default), 'string', 'fraction'))
 
> (this will match "decomposition", which is also "broken" -- it really
> should return a tag followed by a sequence of unicode characters).

Same here:

unicodedata.decomposition(char, format=('string' (default), 
                                        'tuple'))

I'd opt for making the API more customizable rather than trying
to find the one and only true return format ;-)

-- 
Marc-Andre Lemburg
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