ElementTree iterparse strategy

Here's one possible approach: we maintain a path list and peek backwards to find the parent node(s).

path = []
for event, elem in ET.iterparse(file_path, events=("start", "end")):
    if event == 'start':
        path.append(elem.tag)
    elif event == 'end':
        # process the tag
        if elem.tag == 'name':
            if 'members' in path:
                print 'member'
            else:
                print 'nonmember'
        path.pop()

pulldom is excellent for this. You get a sax stream. You can iterate through the stream, and when you find a node that your are interested in, load that node in to a dom fragment.

import xml.dom.pulldom as pulldom
import xpath # from http://code.google.com/p/py-dom-xpath/

events = pulldom.parse('families.xml')
for event, node in events:
    if event == 'START_ELEMENT' and node.tagName=='family':
        events.expandNode(node) # node now contains a dom fragment
        family_name = xpath.findvalue('name', node)
        members = xpath.findvalues('members/name', node)
        print('family name: {0}, members: {1}'.format(family_name, members))

output:

family name: Simpson, members: [u'Hommer', u'Marge', u'Bart']
family name: Griffin, members: [u'Peter', u'Brian', u'Meg']