A working XML parsing example!

http://groups.google.com/group/google-appengine/browse_thread/thread/85b7d03ff0d4ff2b/9fdfec112a4c051a


SimpleXMLTreeBuilder is no longer supported in the latest SDK. Returns
"object is unsubscriptable" error.


Update: I hope this is still useful for people searching for a working
example!

I can confirm that minidom now works in SDK 1.0.2. As I understand
it, this is because pyexpat is now in the GAE whitelist of C
libraries:

http://code.google.com/appengine/kb/libraries.html

I am using SDK 1.0.2 on Windows XP, therefore for this to work I
needed to patch urlfetch_stub.py because the development server was
discarding my URL parameters.

http://code.google.com/p/googleappengine/issues/detail?id=341

You no longer need to use upload a version of the SimpleXMLTreeBuilder
(although this still works) and the code using minidom now looks like
this:

-----

from google.appengine.api import urlfetch
from xml.dom import minidom

WEATHER_URL = 'http://xml.weather.yahoo.com/forecastrss?p=%s'
WEATHER_NS = 'http://xml.weather.yahoo.com/ns/rss/1.0'

def parse( url ) :
result = urlfetch.fetch(url)
if result.status_code == 200:
       return minidom.parseString(result.content)

def weather_for_zip(zip_code):
url = WEATHER_URL % zip_code
dom = parse(url)
forecasts = []
for node in dom.getElementsByTagNameNS(WEATHER_NS, 'forecast'):
    forecasts.append({
        'date': node.getAttribute('date'),
        'low': node.getAttribute('low'),
        'high': node.getAttribute('high'),
        'condition': node.getAttribute('text')
    })
return {
    'forecasts': forecasts,
    'title': dom.getElementsByTagName('title')[0].firstChild.data
}

print 'Content-Type: text/plain'
print ''
print weather_for_zip('94089')


{'title': u'Yahoo! Weather - Sunnyvale, CA', 'forecasts': [{'date': u'22 May 2008', 'high': u'75', 'low': u'53', 'condition': u'Sunny'}, {'date': u'23 May 2008', 'high': u'73', 'low': u'53', 'condition': u'Partly Cloudy'}]}

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http://www.kharakawa.com/kh.log/archives/python/