Updating CouchDB's doc with additional field

gistfile1.txt

>>> import couchdb 
>>> couch = couchdb.Server() 
>>> db = couch['catalog_users']
>>> doc = db['f893955fc22b7ff25fd5d3764a009354']
>>> doc
<Document 'f893955fc22b7ff25fd5d3764a009354'@'19-ea4b426d433b779ff9ed8267b989714e' {'home_zipcode': '', 'city': '', 'fb_user_id': '', 'zipcode': '', 'state': '', 'type': 'Publisher', 'email': 'iamsidd@gmail.com', 'media_url': '', 'status': 'active', 'bio': '', 'couchrest-type': 'Publisher', 'passwd': '97032c0a89cba64bd10f7d221c589f60', 'address1': '', 'address2': '', 'auth': '59b58778-eb69-11e0-9bea-1231390b25d1', 'dob': '', 'key': '59b58778-eb69-11e0-9bea-1231390b25d1', 'super_publisher_id': 'a36c91061da18c0c1ba1c3412409d8aa', 'created_ts': 1338361447, 'name': '', 'access_token': '', 'gender': '', 'publisher_revenue': 0.5, 'customer_type': 'storyteller', 'stories': ['273374'], 'updated_ts': 1338361470, 'published': True}>
>>> doc['internal_rating'] = 4
>>> db.save(doc)
('f893955fc22b7ff25fd5d3764a009354', '20-f5c36653f45f853570f3399793ea560f')