As suggested in issue 2169549, I have now added a number of trove classifiers to PyPI to denote support for certain Python versions, namely Programming Language :: Python :: 2 Programming Language :: Python :: 2.3 Programming Language :: Python :: 2.4 Programming Language :: Python :: 2.5 Programming Language :: Python :: 2.6 Programming Language :: Python :: 2.7 Programming Language :: Python :: 3 Programming Language :: Python :: 3.0 Programming Language :: Python :: 3.1 With these, packages can indicate that they support 2.x (but not 3.x), or that they have been tested/written for specific Python releases. As a side effect, packages can now expressly state that they support Python 3000. Regards, Martin