[Python-Dev] 2.7 Release? 2.7 == last of the 2.x line?

[David Cournapeau]

On Tue, Nov 3, 2009 at 8:40 PM, Antoine Pitrou <solipsis at pitrou.net> wrote:
> Sturla Molden <sturla <at> molden.no> writes:
>>
>> Porting NumPy is not a trivial issue. It might take
>> a complete rewrite of the whole C base using Cython.
>
> I don't see why they would need a rewrite.

(let me know if those numpy-specific discussions are considered OT0

There is certainly no need for a full rewrite, no. I am still unclear
on the range of things to change for 3.x, but the C changes are not
small, especially since numpy uses "dark" areas of python C extension.
The long vs int, strings vs bytes will take some time.

AFAIK, the only thing which has been attempted so far is porting our
own distutils extension to python 3.x, but I have not integrated those
changes yet.

> between 2.x and 3.x. Cython itself is supposed to support both 2.x and 3.x,
> isn't it?

Yes - but no numpy code use cython ATM, except for the random
generators, which would almost certainly be trivial to convert.

The idea which has been discussed so far is that for *some* code which
need significant changes or rewrite, using cython instead of C may be
beneficial, as it would give the 3.x code "for free". Having more
cython and less C could also bring more contributors - that would
actually be the biggest incentive, as the number of people who know
the core C code of numpy is too small.

> That's interesting, because PEP 3118 was pushed mainly by a prominent member of
> the NumPy community and some of its features are almost dedicated to NumPy.

I have not been involved with PEP 3118 discussion, so cannot comment
on the reason why it is not fully supported yet by numpy.

But I think that's a different issue altogether - PEP 3118 goal is for
interoperation with other packages. We can port to PEP 3118 without
porting to 3.x, and we can port to 3.x without taking care of PEP
3118.

David