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

[M.-A. Lemburg]

Tim Peters wrote:
> 
> [Tim]
> > >>> unicodedata.numeric(u"\N{PLANCK CONSTANT OVER TWO PI}")
> > Traceback (most recent call last):
> >   File "<stdin>", line 1, in ?
> > ValueError: not a numeric character
> > >>> unicodedata.numeric(u"\N{EULER CONSTANT}")
> > Traceback (most recent call last):
> >   File "<stdin>", line 1, in ?
> > ValueError: not a numeric character
> > >>> unicodedata.numeric(u"\N{AIRSPEED OF AFRICAN SWALLOW}")
> > UnicodeError: Unicode-Escape decoding error: Invalid Unicode
>                 Character Name
> 
> [MAL]
> > Perhaps you should submit these for Unicode 4.0 ;-)
> 
> Note that the first two are already there; they just don't have an
> associated numerical value.  The last one was a hint that I was trying to
> write a frivolous msg while giving my "<wink>" key a break <wink>.

That's what I meant: you should submit the numeric values for
the first two and opt for addition of the last.
 
> > 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.

It is needed for Unicode 3.0 standard compliance and for whoever
wants to use this data. Since the Unicode database explicitly
contains fractions, I think adding the .rational() API would
make sense to provide a different access method to this data.

-- 
Marc-Andre Lemburg
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