How do I parse the JSON array when trying to load facebook friends into Google App Engine facebook example?

I am just starting out on an idea of a Google App engine app that interacts with Facebook. All my coding experience is number crunching in Matlab, which is so high level, a lot of real coders haven't even heard of it. I am attempting to extend the example provided by facebook here. So far, the only thing I've tried to add is reading in a list of the user's friends. I've put comments ahead of the lines I added in my version of the code below. The code succeeds in loading in the user from facebook. I can access the various user properties and display them. However, the friends property that I tried to add is always a blank list. I think the difference is that things like name and id are JSON strings that can be handled like Python strings but graph.get_connections returns an array of JSON objects as the list of friends. I think I should be turning this JSON array into a python dictionary but I don't know how. Of course, I may be completely wrong about that.

I would really appreciate a tip as to how I can get the user's list of friends into a python list of some kind that I can manipulate.

Thanks,

Dessie

#!/usr/bin/env python
#
# Copyright 2010 Facebook
#

"""A barebones AppEngine application that uses Facebook for login."""

FACEBOOK_APP_ID = "my_facebook_app_id"
FACEBOOK_APP_SECRET = "my_facebook_app_secret"

import facebook
import os.path
import wsgiref.handlers 
import logging
import platform

from google.appengine.ext import db
from google.appengine.ext import webapp
from google.appengine.ext.webapp import util
from google.appengine.ext.webapp import template


class User(db.Model):
    id = db.StringProperty(required=True)
    created = db.DateTimeProperty(auto_now_add=True)
    updated = db.DateTimeProperty(auto_now=True)
    name = db.StringProperty(required=True)
    profile_url = db.StringProperty(required=True)
    access_token = db.StringProperty(required=True)
    #Following line added by me 
    friends = db.StringListProperty()

class BaseHandler(webapp.RequestHandler):
    """Provides access to the active Facebook user in self.current_user

    The property is lazy-loaded on first access, using the cookie saved
    by the Facebook JavaScript SDK to determine the user ID of the active
    user. See http://developers.facebook.com/docs/authentication/ for
    more information.
    """

    @property
    def current_user(self):
        if not hasattr(self, "_current_user"):
            self._current_user = None
            cookie = facebook.get_user_from_cookie(
                self.request.cookies, FACEBOOK_APP_ID, FACEBOOK_APP_SECRET)
            if cookie:
                # Store a local instance of the user data so we don't need
                # a round-trip to Facebook on every request
                user = User.get_by_key_name(cookie["uid"])
                if not user:
                    graph = facebook.GraphAPI(cookie["access_token"])
                    profile = graph.get_object("me")
            id=str(profile["id"]
            #Following 2 lines added by me  
            fs=graph.get_connections("me","friends")
            logging.info(fs)    
                    user = User(key_name=str(profile["id"]),
                                id=str(profile["id"]),
                                name=profile["name"],
                                profile_url=profile["link"],
                                access_token=cookie["access_token"],
                #Following line added by me 
                friends=fs)
                    user.put()
                elif user.access_token != cookie["access_token"]:
     开发者_开发百科               user.access_token = cookie["access_token"]
                    user.put()
                self._current_user = user

        return self._current_user


class HomeHandler(BaseHandler):
    def get(self):
    #Following line added by me 
    logging.info(self.current_user.friends)
        path = os.path.join(os.path.dirname(__file__), "example.html")
        args = dict(current_user=self.current_user,
                    facebook_app_id=FACEBOOK_APP_ID)
        self.response.out.write(template.render(path, args))

def main():
    util.run_wsgi_app(webapp.WSGIApplication([(r"/", HomeHandler)]))


if __name__ == "__main__":
    main()

I think I should be turning this JSON array into a python dictionary but I don't know how.

simplejson is included in app-engine, in django's utils package.

from django.utils import simplejson as json

def your_method(ars):
   # do what ever you are doing...
   dict_of_friends = json.loads(json_string)

Having trouble with commenting tool, the time limit is throwing me off. Robert's answer seems right but it didn't work in my script. I finally got it to work with a different approach

import re
import urllib2

#after I created the user
url = "https://graph.facebook.com/" + user.id + "/friends?access_token=" + user.access_token
response = urllib2.urlopen(url)
fb_response = response.read()
x = re.findall(r'"\d+"',fb_response)
friend_list = [a.strip('"') for a in x]
user.friends = friend_list
user.put()  

You don't have to convert explicitly from json at facebook python library.

just start from fs["data"], for example if you want to count the number of friends.

fs=graph.get_connections("me","friends")
friends_count = len(fs["data"])