[Python-3000] PEP 3101 clarification requests

[Guido van Rossum]

On 8/20/07, Eric Smith <eric+python-dev at trueblade.com> wrote:
> Guido van Rossum wrote:
> > On 8/19/07, Eric Smith <eric+python-dev at trueblade.com> wrote:
> >> Talin wrote:
> >>> Wow, excellent feedback. I've added your email to the list of reminders
> >>> for the next round of edits.
> >> Here's something else for future edits:
> >>
> >> 1. When converting a string to an integer, what should the rules be?
> >> Should:
> >> format("0xd", "d")
> >> produce "13", or should it be an error?
> >
> > I can't see that as anything besides an error. There should be no
> > implicit conversions from strings to ints.
>
> OK.  I had been planning on implicitly converting between strings, ints,
> and floats (in all directions).  The PEP doesn't really say.
>
> So the only implicit conversions will be:
> int->float
> int->string
> float->int
> float->string
>
> Now that I look at it, % doesn't support string->float or string->int
> conversions.  Not sure where I got the idea it was needed.  I'll remove
> it and update my test cases.
>
> Converting to strings doesn't really buy you much, since we have the !s
> specifier. But I think it's needed for backward compatibility with %
> formatting.

Why? The conversion code can just generate !s:-20 instead of :-20s.

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)