parse an XML file and build a tree. Automatic support for
      ZLIB/Compress compressed document is provided by default if
       found at compile-time.

def parseFile(filename):
    """parse an XML file and build a tree. Automatic support for
      ZLIB/Compress compressed document is provided by default if
       found at compile-time. """
    ret = libxml2mod.xmlParseFile(filename)
    if ret is None:raise parserError('xmlParseFile() failed')
    return xmlDoc(_obj=ret)