Hopefully this will help. Note the callback occurs about halfway up the stack. Traceback (most recent call last): File "index.py", line 107, in <module> rslt_tree = trans(in_tree, mobile="'" + mobile_str + "'") File "xslt.pxi", line 582, in lxml.etree.XSLT.__call__ (src/lxml/lxml.etree.c:139795) File "lxml.etree.pyx", line 294, in lxml.etree._ExceptionContext._raise_if_stored (src/lxml/lxml.etree.c:9359) File "xsltext.pxi", line 195, in lxml.etree._callExtensionElement (src/lxml/lxml.etree.c:144738) File "index.py", line 100, in execute output_parent.append(results) File "readonlytree.pxi", line 475, in lxml.etree._AppendOnlyElementProxy.append (src/lxml/lxml.etree.c:69888) File "readonlytree.pxi", line 481, in lxml.etree._AppendOnlyElementProxy.append (src/lxml/lxml.etree.c:69807) File "readonlytree.pxi", line 534, in lxml.etree._roNodeOf (src/lxml/lxml.etree.c:70448) TypeError: invalid argument type <type 'list'> On 05/06/2013 04:01 PM, Simon Sapin wrote:

Le 06/05/2013 21:51, Eric Levy a écrit :

...

I may have put the issue in a confusing way, because I used the term "string", but I am actually trying to capture a an entire results tree (or the first item if there is a list of results), and if possible, recursively apply XSLT templates to those results. Consequently, I cannot use the XPath text() function because this flattens the results, rather than keeping them as a tree. I should also note that in the line reading "results = self.apply_templates(context, string)", I tried changing "string" to "string[0]", but the effect was the same.

I hope this makes clearer what I am trying to do.

Ok, so forget the part about strings and text. Can you copy the full traceback you get with string[0]?

Cheers,