Python + goo.gl の API で短縮URL

Googleの短縮URLのAPIが提供されたので、Pythonでとりあえず短縮だけしてみた。
http://code.google.com/intl/ja/apis/urlshortener/v1/getting_started.html

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import urllib2
import simplejson

API_URL = 'https://www.googleapis.com/urlshortener/v1/url'
API_KEY = None

def shorten(longUrl):
    if isinstance(longUrl, unicode):
        longUrl = longUrl.encode('utf-8')
       
    if API_KEY is None:
        data = '{longUrl:"%s"}' % (longUrl)
    else:
        data = '{longUrl:"%s", key:"%s"}' % (longUrl, API_KEY)
    req = urllib2.Request(API_URL, data)
    req.add_header('Content-Type', 'application/json')
    
    result = urllib2.urlopen(req)
    return simplejson.loads(result.read()).get('id')


if __name__ == '__main__':
    print shorten(u'http://ja.wikipedia.org/wiki/うさぎ')
    print shorten(u'http://ja.uncyclopedia.info/wiki/うさぎ')

結果

http://goo.gl/LyJjn
http://goo.gl/MBCBo