I know a little of dom, and would like to learn about ElementTree. Python 2.6 has a somewhat older implementation of ElementTree, but still usable. However, it looks like it
From https://docs.python.org/3/library/xml.etree.elementtree.html:
Changed in version 3.3: This module will use a fast implementation whenever available. The xml.etree.cElementTree module is deprecated.
So for Python 3.3 and higher just use:
import xml.etree.ElementTree as ET