[Distutils] Deprecating little used file types/extensions on PyPI?

[Daniel Holth]

On Tue, Aug 16, 2016 at 12:15 PM Donald Stufft <donald at stufft.io> wrote:

> On Aug 16, 2016, at 11:51 AM, Brett Cannon <brett at python.org> wrote:
>
> One thing to remember is that Windows can't read tar files natively while
> it can for zip files. Now you can easily download tools on Windows to read
> tar files and thanks to Bash on Windows you even have it included once you
> turn that feature on.
>
>
> This is true, but I think that using .tar.gz by default still makes sense
> because it’s still the vast bulk of what people actually release to PyPI.
> So it represents the status quo and switching to zip as the default would
> break a lot of things.
>
>
> The other point is we have a zip importer in Python but not a .tar.gz one. I
> don't know how often anyone actually downloads a zip file directly from
> PyPI and then tack it on to their sys.path for importing, but that is
> currently possible.
>
>
> A sdist is not an acceptable format for adding to sys.path. While in many,
> simple cases, it will “just work”, that’s more of an implementation detail
> than anything else. There are many projects which simply do not run or
> error out if you do this. I don’t think worrying about something that sort
> of works, sometimes, is a big deal.
>
>
> I doubt either of these points are important enough to continue to support
> zip files for sdists, but I just wanted to point it out. At worst this is
> something to think about if we ever do formalize the sdist format and come
> up with a custom file extension.
>
>
> If we make a sdist 2.0 with a new format, I do think it makes sense to
> make it a zipfile like wheel already is (which reduces the internal formats
> down from 2 to 1), not for the reasons above though, just for consistency
> with wheel.
>

ZIP is a fantastically designed file format. JAR, IPA (iPhone), all are ZIP
files. The only thing I sometimes wonder about for wheel is whether it
would be worth the trouble to support greater compression with something
like .zip.xz (an uncompressed ZIP inside a wrapper, possibly another ZIP)
since ZIP compresses each file individually and does not compress its
metadata. But most packages are quite small.

ZIP's greatest weakness is also its greatest strength, as ZIP allows random
access to its members and very fast access to its metadata. This is why it
makes sense to have a ZIP importer but not a .tar.gz importer.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/distutils-sig/attachments/20160816/d8422a76/attachment-0001.html>