Saturday, November 6, 2010

Release classifiers in distutils/pypi

Thanks to Doug Napoleone I'm now aware there is already a convention followed for the python and framework versions, but it appears that not enough people are aware of it. This post is pretty much a reposting of the second comment of the post immediately preceding this one and Doug gets full credit for this post. I'm just repeating his message:

The release classifiers in this post should be included in the standard distutils documentation. For the moment, you can see the full list of classifiers here:

For the python language version the classifier is:

Programming Language :: Python :: x.y.z

With each version on it's own line. That way you can browse the repository by python version (see the bottom of the page):

There is also support for frameworks which you can see on that page as well. There it is done with:

Framework :: Django :: x.y.z

There is Zope, Plone, and a number of other frameworks already there.

In the example you gave the proper, and supported way of writing the metadata is:

Programming Language :: Python
Programming Language :: Python :: 2.4
Programming Language :: Python :: 2.5
Programming Language :: Python :: 2.6
Programming Language :: Python :: 2.7
Framework :: Django
Framework :: Django :: 0.96
Framework :: Django :: 1.0
Framework :: Django :: 1.1
Framework :: Django :: 1.2.1
Framework :: Django :: 1.3

Now it becomes a matter of education and illumination. This should be in the standard distutils documentation and arguably the home page of PyPI (or easily found there). And Django Packages will be supporting this functionality in the near future.

A request for new pypi classifiers

This request is to help enhance Django Packages, PyPM Index, and other projects. This would also help the Python community at large.

Would it be possible that a standard be established for listing in PyPI classifiers which versions of a package is known to operate? Using James Bennett's django-registration at as an example (see my bolded, last two lines to understand what I'm trying to demonstrate):
Development Status :: 5 - Production/Stable
Environment :: Web Environment
Framework :: Django
Intended Audience :: Developers
License :: OSI Approved :: BSD License
Operating System :: OS Independent
Programming Language :: Python
Topic :: Utilities
Python Versions :: 2.4, 2.5, 2.6, 2.7
Django Versions :: 0.96, 1.0, 1.1, 1.2.1, 1.3
The metadata system I'm writing about in this blog post is specified on the distutils documentation page.

I picked a Django package but this could be for Zope, Pyramid, PyQT, or anything.

If we had something like this in place then people could quickly identify on PyPI and other resources if a tool can be of use to them or if it needs to be updated to the latest code base. If this already exists, then can someone point me at the existing specification so I can promote it?

Edit: Noah Kantrowitz suggested I take a look at the 'requires' keyword which is part of the distutils spec. However, this does not show up in the PyPI API ( and so doesn't fit our needs.