gistfile1.txt

>>> doc = db['foo']
>>> doc
{u'a': 1, u'_rev': u'1-23202479633c2b380f79507a776743d5', u'_id': u'foo'}
>>> doc.update({'a': 2})
>>> db.save_doc(doc)
>>> db['foo']
{u'a': 2, u'_rev': u'2-71173597778497e0a6aa176963f222db', u'_id': u'foo'}