Hi, the other day I had to pickle objectified trees. I just thought to share my findings. Pickling is about serialization. IMHO the natural serialization of an objectified tree is its XML representation. So the following basically does that: -------------------------- import copy_reg import lxml.etree import lxml.objectify def treeFactory(state): """Un-Pickle factory.""" return lxml.objectify.fromstring(state) copy_reg.constructor(treeFactory) def reduceObjectifiedElement(object): """Reduce function for lxml.objectify trees. See http://docs.python.org/lib/pickle-protocol.html for details. """ return (treeFactory, (lxml.etree.tostring(object), )) copy_reg.pickle(lxml.objectify.ObjectifiedElement, reduceObjectifiedElement, treeFactory) ----------------------------------------- You might consider just registering the reduce function in lxml itself. Shouldn't hurt, should it. -- Christian Zagrodnick gocept gmbh & co. kg · forsterstrasse 29 · 06112 halle/saale www.gocept.com · fon. +49 345 12298894 · fax. +49 345 12298891