**>db.blog.findOne()
{ "_id":"djsofjwo"
"comments":[
{
"comment":"good post",
"author":"john"
"vote":0}
{
"comment":"I thought it is too short"
"author":"bob"
"vote":3
}
{
"comment":"good"
"author":"light"
"vote":1
}
]
}
>db.blog.update({"post":post_id},{"$inc":{"comments.0.vote":1}})
这样是在shell 的环境下对comments数组中位置为0的评论修改,使投票加一。在pymongo下怎么用python代码实现同样的功能?**