Hi,
I don't want to be rude but take a look at this:
http://stackoverflow.com/questions/12591/using-an-xml-catalog-with-pythons-lxml
I have tried for an internet disconnected machine to lxml parse with xsd validation
even using no_network=True I still get an insistence that "connection refused".
I do not have lots of experience with python and most of the code is from lxml.de .
Sincerely,
JC Magras