Question

I am building an application for Facebook using Google App Engine. I was trying to compare friends in my user’s Facebook account to those already in my application, so I could add them to the database if they are friends in Facebook but not in my application, or not if they are already friends in both. I was trying something like this:

request = graph.request("/me/friends")
user = User.get_by_key_name(self.session.id)
list = []
for x in user.friends:
    list.append(x.user)

for friend in request["data"]:
    if User.get_by_key_name(friend["id"]):
        friendt = User.get_by_key_name(friend["id"])
        if friendt.key not in user.friends:
            newfriend = Friend(friend = user,
                               user = friendt,
                               id = friendt.id)
            newfriend.put()

graph.request returns an object with the user’s friends. How do I compare content in te two lists of retrieved objects. It doesn’t necessarily need to be Facebook related.

(I know this question may be quite silly, but it is really being a pain for me.)

Answer 1

If you upgrade to NDB, the “in” operator will actually work; NDB implements a proper eq operator on Model instances. Note that the key is also compared, so entities that have the same property values but different keys are considered unequal. If you want to ignore the key, consider comparing e1._to_dict() == e2._to_dict().