import Martel
from xml.sax import saxutils

expression = Martel.Re(r"AC   (?P<ac_number>\w+);( (?P<ac_number>\w+);)*")
ac = Martel.Group("AC", expression)
parser = ac.make_parser()

parser.setContentHandler(saxutils.XMLGenerator())

parser.parseString("AC   P97430; O09081; O09082;")

>>> parser.parseString("AC   P97430; O09081; O09082;")
<?xml version="1.0" encoding="iso-8859-1"?>
<AC>AC   <ac_number>P97430</ac_number>; <ac_number>O09081</ac_number>; \
<ac_number>O09082</ac_number>;</AC>