I'd like to use etree, expat or similar, though I understood etree is easier to use. But how do I install that when I already have Python 2.7.2 installed on Ubuntu 11.10?

All documentation I can find through Google suggests that xml parsing is available by default for Python. Or at least when I search for install xml parser python, or any combination of similar words, also including etree or expat I can't find what steps to take (a commandline install method).