[Python-Dev] future_builtins

[Guido van Rossum]

On Sat, Feb 23, 2008 at 11:34 AM, Eric Smith
<eric+python-dev at trueblade.com> wrote:
> Guido van Rossum wrote:
>  > On Sat, Feb 23, 2008 at 9:01 AM, Eric Smith
>  > <eric+python-dev at trueblade.com> wrote:
>  >> Guido van Rossum wrote:
>  >>  > I don't think a -3 warning for oct or hex would do any good.
>  >>
>  >>  I'm curious as to why.  oct and hex have different behavior in 3.0,
>  >>  which is what I thought -3 was for.  hex might be overkill, as the only
>  >>  differences are the "L" and the __hex__ behavior.  But oct is always
>  >>  different.
>  >
>  > Well, yeah, but what are you going to do about it? Not use oct()? I
>  > expect that *most* programs using oct() or hex() will work just as
>  > well under 3.0; typically the output is just printed, not parsed or
>  > otherwise further processed.
>  >
>  > I think -3 should only warn about things where it's easy to modify the
>  > code so that it continues to work under 2.6 but will also work under
>  > 3.0. Forcing people to use "%o" just to get rid of the warning doesn't
>  > make sense to me.

>  My thinking wast that using code that run under -3 without warnings
>  would work exactly the same under 3.0, after running through 2to3.

That's wishful thinking. :)

> So if oct() gave me a warning, I'd switch to the future_builtins version,
>  and do whatever it took to get my program running again under 2.6 (which
>  might involve not caring that the output changed from 2.5 to 2.6).
>  Maybe it's wishful thinking.  I'm not too worried about this specific
>  case, either.

I think practicality says we should not warn about this.

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