The proposal of this package is to provide XPath 1.0, 2.0 and 3.0 selectors for ElementTree XML data structures, both for the standard ElementTree library and for the lxml.etree library. For lxml.etree this package can be useful for providing XPath 2.0 3.0 selectors, because lxml.etree already has it's own implementation of XPath 1.0.