Apologies for the cross-post, but I want to make sure that everyone who cares about Python on both Debian and Ubuntu gets a chance to weigh in. On Friday, Guido approved and I landed the implementation of PEP 3147 on the py3k trunk (what will be Python 3.2). This allows multiple versions of Python to coexist on the same system without the need for symlinks to handle pyc file incompatibility. http://www.python.org/dev/peps/pep-3147/ This will be officially supported in Python starting with 3.2. It will not however be available in upstream Python 2.7. The PEP does recognize however that distros may want to back port the feature to get its advantages now. Although I have not yet tried to do so, I think the essential elements of the PEP should be fairly easy to back port to Python 2.6, 2.7 and 3.1. The question is, should we do this? As the PEP outlines, my preference would be to back port it but *not* enable this by default in any Python < 3.2. Instead, the back port would add a -Xenablecachedir switch, and an associated $PYTHONENABLECACHEDIR environment variable that would have to be used to enable PEP 3147 pyc paths. Of course, this would have to be supported in python-support and python-central too, but I believe Piotr has started working on this. With the back port it means that any Python modules installed by apt will not need symlinks in order to share both the source and pyc locations. Normal Python developers working on their own code however would still get traditional pyc file locations by default (but of course, there would be nothing stopping them from setting the above switch/envar). It's possible that Debian and Ubuntu will come to different decisions about what to do, but it would be nice if we could reach consensus. I would be willing to do the work to back port the essential bits to earlier Pythons, or at least spend some time to see whether it is feasible. I know that given the release schedule of Python 2.7, it's possible that Ubuntu 10.10 could include 2.6, 2.7, and 3.1, though I don't think that's been decided yet. I'm not sure how Python 2.7's scheduled release date of 2010-06-26 matches Debian's release schedule. (Given that lenny was released on 2010-01-30 I'm guessing it will be a while.) Before I start working on this though, I'd like to get your opinion as to whether it is worth it. Thanks, -Barry
Attachment:
signature.asc
Description: PGP signature