Returning the ids of the top-10 most retweeted tweets

grouped, top-n query in MongoDB.py

def get_retweets(hashtag):
    db = create_connection()
    tweets = db.conftweets
    regexp = re.compile(hashtag, re.IGNORECASE)
    grpd = tweets.group( key = {'retweeted_status.id': True},
        condition = {'entities.hashtags.text': regexp,
            'retweeted_status.id': {'$ne': None}},
        initial = {'count': 0},
        reduce = 'function(doc, prev) {prev.count += 1}')
    return grpd

n = 10
srtd = sorted(mongotools.get_retweets('df10'),key=itemgetter('count'),reverse=True)
top_retweets = srtd[0:n]