PyMongo光标-修改和使用值

Question

I am encountering difficulties with my PyMongo script: My documents have a field "used" : "false" or "true". I want to iterate over the documents whose "use" fields are "false" and use their "friends" field (which is an array of _id values) to add their own _id value to the friends field of every person who is also in the current person's friends field. It should look somewhat like this:

"person_id": "Hans",
"used": "false",
"friends": {
    "Hugo",
    "Kunigunde"
}

Afterwards, Hugo and Kunigunde should have Hans as entry in their friends list and used of Hans should be true . My current approach is

cursor = db.People.find({"used": "false" })
            for document in cursor:

But I don't know how to continue this. Thanks for helping!

Answer 1

For adding Hans to Hugo and Kunigundes friendslist:

for friend in cursor_pointing_to_Hans['friends']:
    friend_list=db.People.find({'person_id':friend})['friends']
    friend_list.append(cursor_pointing_to_Hans['person_id'])
    db.People.update({'person_id':friend},{'friends':friend_list})

For setting Hans used field to true:

db.People.update({'person_id':cursor_pointing_to_Hans['person_id']}, {'used':"true"})

Furthermore as you are working in Python I´d suggest to use the boolean python values True and False instead of the Strings "true" and "false"