lxml-flow.py

from sys import exit
from lxml import etree
 
response = 'some xml response here'
 
try:
    doc = etree.XML(response.strip())
    code = doc.findtext('code')
    print code
except etree.XMLSyntaxError:
    print 'XML parsing error.'
    exit(1)

if code == '200':
    # store the id somewhere
    id = doc.findtext('id')
else:
    # handle errors, do more stuff
    print doc.findtext('error')
    exit(1)

exit(0)