Currently, a search like `emerge -s @dev-python/sip` will return lots of irrelevant results from the dev-python category. The problem is that the category and package name similarities are not weighed separately, so anything in the dev-python category has an artificially high similarity.
Patch sent for review: https://archives.gentoo.org/gentoo-portage-dev/message/f2e41bcad09a943dae94413677f6265b https://github.com/gentoo/portage/pull/179
This is in the master branch: https://gitweb.gentoo.org/proj/portage.git/commit/?id=66df1d045a64f8ad6453d9668cdb66980c128b69