Hi Noah, Noah Slater wrote:

I would like to extend the _ElementTree class to include some handy methods - write_xml/write_xhtml/write_html are examples.

What would be the best way to go about this. While I can extend the base class I am struggling to understand how I can replace etree.parse() to return these objects.

I would create either global functions or an external class (say, ElementTreeWriter) to implement this kind of functionality. There is no easy way to replace the internal _ElementTree class. Note that there is nothing you could do from a Python subclass that you couldn't do from an external function.

In addition, this should enable me to return extended ElementTrees instead of ResultTrees after an XSLT transform.

May I ask why you would want to do that?

While I am on the subject, what is the reason for ResultTree objects as a pose to ElementTree. Why make the distinction to the user?

There is a related FAQ entry, near the bottom of the file. http://codespeak.net/svn/lxml/trunk/doc/FAQ.txt Feel free to ask back if it is unclear or doesn't answer your questions. Stefan