[Python-ideas] [Python-Dev] Unicode minus sign in numeric conversions

[MRAB]

On 09/06/2013 17:13, Stephen J. Turnbull wrote:
> Steven D'Aprano writes:
>
>   > > But Python goes much farther.  float('٢.๑') also returns 2.1 (not to
>   > > mention that int('٢๑') returns 21).
>   >
>   > Yes. And why is this a problem? There is no ambiguity. It might
>   > look untidy to be mixing Arab and Thai numerals in the same number,
>   > but it is still well-defined.
>
> To whom?  Unicode didacts, maybe, but I doubt there are any real users
> who would consider that well-defined.  So the same arguments you made
> for not permitting non-ASCII numerals in Python source code apply
> here, although they are somewhat weaker when applied to numeric data
> expressed as text.
>
> In any case, there's not really that much use for this generality of
> numerals.  On the one hand, I think these days anyone who uses
> information technology is fluent in ASCII numeration.  On the other,
> if you want to allow people to write in other scripts, you probably
> are dealing with "naive" users who should be allowed to use grouping
> characters and the usual conventions for their locale, and int () and
> float() just aren't good enough anyway.
>
I was thinking that we could also add a function for numeric
translation/transliteration somewhere:

>>> # Translate toBengali
>>> translate_number('0123456789', 'bengali')
'০১২৩৪৫৬৭৮৯'
>>> # Translate to Oriya
>>> translate_number('0123456789', 'oriya')
'୦୧୨୩୪୫୬୭୮୯'
 >>> # Defaults to translating to ASCII range
>>> translate_number('୦୧୨୩୪୫୬୭୮୯')
'0123456789'

Non-numeric strings and mixed scripts would raise an exception.