from lxml import etree
t = etree.fromstring(gmp.send_command('<get_tasks filter="rows=-1"/>').encode())
for task in t.findall('.//task'):
    if 'first-discovery' in (task.findtext('name') or ''):
        print('id=' + task.get('id'))
        print('status=' + (task.findtext('status') or '?'))
        print('progress=' + (task.findtext('progress') or '?'))