xml.etree.ElementTreeを使います。
import xml.etree.ElementTree as etree
xml = """
<test>
<name>sample name</name>
<desc type='text'>sample desc</desc>
<option>
<value>value1</value>
</option>
<option>
<value>value2</value>
</option>
<option>
<value>value3</value>
</option>
</test>
"""
elem = etree.fromstring(xml)
self.response.out.write( '<br />name=' + elem.findtext('name') )
self.response.out.write( '<br />desc=' + elem.findtext('desc'))
self.response.out.write( '<br />desc=' + elem.find('desc').text)
self.response.out.write( '<br />desc type=' + elem.find('desc').get('type') )
for opt in elem.findall('option'):
self.response.out.write('<br />option ' + opt.find('value').text )