from __past__ import integerDivision (was Re: A modest PEP0238 suggestion)

[Chris Gonnerman]

----- Original Message -----
From: "Guido van Rossum" <guido at python.org>


> missive at frontiernet.net (Lee Harr) writes:
> > we already have people importing things from the __future__,
> > how difficult would it be to let people drag things from the __past__?
>
> This has been suggested before.  It's just as easy (in fact in a sense
> it's easier, since you know what the past was, but you may be wrong
> about what the future might bring :-).  But the problem (as I see it)
> is that there will never be a point where we can throw away support
> for the past behavior, because there will always be code around that
> imports it.

I disagree here... in fact I think this is a *plus*.  That is, when version
3.0 comes out (for instance) and the code says "from __past__ import
division"
then you get an exception.  This is GOOD... obvious code breakage is much
safer than silent code breakage.  You get notified right away, when the new
version compiles the code, that this bird don't fly no more.

My proposal for

    from __numerics__ import original

is the same sort of thing.  When the "original" semantics disappear, the
user gets an obvious error message.