PEP 238 (revised)

Guido van Rossum guido at
Fri Jul 27 10:15:29 EDT 2001

paul at (Paul Boddie) writes:

> I'm really disappointed that the "migration" process hasn't been
> addressed in the PEP, since the disruptive nature of the changes to
> division constitute my principal objection to the adoption of these
> changes. I get the impression that there isn't a good solution to this
> problem, and since this situation could hinder "progress", it is being
> "swept under the carpet".

What exactly would you like to see addressed in the PEP?  Should I
spell out that you have to do a query replace of / to //,approving the
replace if the arguments are integers?  That seems pretty trivial.  I
suppose tools will be created to do most of the hard work, but I don't
really see them within the scope of the PEP.

> But possibly the first thing anyone with any investment in the
> language should be thinking upon starting to read the PEP is: "How on
> Earth am I going to know what needs changing, and how much time and
> money am I going to be spending to adapt to this?"

Again a question the PEP cannot answer for you.  All the PEP can do is
give you enough time, and assurance that the switch won't be silent.

> One could suggest (as I did before) that until such time as effective
> type inference/analysis tools are available, this change shouldn't go
> through.

Which change are you speaking of?  Adding the future division
statement and the // operator?  Or changing the default meaning of /?
The former need to be done ASAP to give people enough time to get used
to it.  The latter won't happen until Python 3.0, which is years away.

--Guido van Rossum (home page:

More information about the Python-list mailing list