There appears to be no way to search PyPI for packages that are compatible with Python 3.x. There are classifiers for 'Programming Language' including 'Programming Language :: Python :: 3' but that seems to be for implementation language since there are so many packages that specify C. There are a total of 109 packages classified with Python :: [3, 3.0, 3.1] out of a total of 4829 packages. http://pypi.python.org/pypi?:action=browse&show=all&c=214&c=533
The search box appears to search for any word entered so a search like "xml 3.0" or "xml AND 3.0" does not help. Some packages include version information in the Py Version column of their download lists or embedded in the download file names. Projects are often constrained to a particular set of Python versions so need to choose packages that will work with those versions. It would be helpful if PyPI made this information more visible and searchable. Neil -- http://mail.python.org/mailman/listinfo/python-list