Postgres Nomenklatura Client

nomenklatura.sql

CREATE OR REPLACE FUNCTION nomenklatura (key text, dataset text, api_key text)
  RETURNS text
AS $$
    import json, urllib, urllib2
    url = 'http://nomenklatura.okfnlabs.org/%s/lookup?' % dataset
    url += urllib.urlencode({'api_key': api_key, 'key': key})
    req  = urllib2.Request(url, None, {'Accept': 'application/json'})
    try:
        fh = urllib2.urlopen(req)
        data = json.loads(fh.read())
        if data.get('is_matched'):
            return data.get('value').get('value')
    except urllib2.HTTPError:
        pass
    return None
$$ LANGUAGE plpythonu;