how to use python xml.etree.ElementTree to parse eBay API response?

I am trying to use xml.etree.ElementTree to parse responses from eBay finding API, findItemsByProduct. After lengthy trial and error, I came up with this code开发者_StackOverflow中文版 which prints some data:

import urllib
from xml.etree import ElementTree as ET

appID = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
isbn = '3868731342'

namespace = '{http://www.ebay.com/marketplace/search/v1/services}'

url = 'http://svcs.ebay.com/services/search/FindingService/v1?' \
    + 'OPERATION-NAME=findItemsByProduct' \
    + '&SERVICE-VERSION=1.0.0' \
    + '&GLOBAL-ID=EBAY-DE' \
    + '&SECURITY-APPNAME=' + appID \
    + '&RESPONSE-DATA-FORMAT=XML' \
    + '&REST-PAYLOAD' \
    + '&productId.@type=ISBN&productId=' + isbn

root = ET.parse(urllib.urlopen(url)).getroot()

for parts in root:
    if parts.tag == (namespace + 'searchResult'):
        for item in list(parts):
            for a in list(item):
                if a.tag == (namespace + 'itemId'):
                    print 'itemId: ' + a.text
                if a.tag == (namespace + 'title'):
                    print 'title: ' + a.text

But that seems not very elegant, how can I get the 'itemId' and 'title' without looping over all attributes and checking if it is the one I want? I tried using things like .get(namespace + 'itemId') and .find(namespace + 'itemId') and .attrib.get(namespace + 'itemId') but nothing really worked.

Can someone maybe show me how to do this using some python wrapper for this API? I saw easyBay, ebay-sdk-python and pyeBay but I didn't manage to get any of them to do what I want. Is there any eBay python API which is worthwhile to use for this?

You can use ElementTree. If you want to get the items you can use findall and the path to the items, then iterate over the list of items:

items = root.findall(namespace+'searchResult/'+namespace+'item')
for item in items: 
     item.find(namespace+'itemId').text
     item.find(namespace+'title').text

To get directly to the first itemId from the root:

root.find(namespace+'searchResult/'+namespace+'item/'+namespace+'itemId')

Basically, the find method uses XPath to retrieve elements more than one level below the subelements. See also Effbot's explanation of XPath support in ElementTree