Error PyReverse / PyArgo on Windows XP Python 2.3.2

[Markus Faust]

Hi,

when processing

    pyargo BosorPost.py

I get the error

parsing project
   _ parsing file BosorPost.py
:: using minidom
--------------------------------------------------------------------------------
generating XMI UML
--------------------------------------------------------------------------------
generating diagrams definitions file
--------------------------------------------------------------------------------
writing XMI file to No_Name.xmi
Traceback (most recent call last):
   File "<string>", line 1, in ?
   File "E:\Python23\Lib\site-packages\logilab\pyreverse\pyargo.py", 
line 231, in Run
     w.write_xmi(xmi_doc)
   File "E:\Python23\Lib\site-packages\logilab\pyreverse\pyargo.py", 
line 35, in write_xmi
     from xml.dom.ext import PrettyPrint
ImportError: No module named ext


Where is the lib. with module ext?

Thanks in advance!
Markus