如何在加载Facebook好友到Google App Engine示例时解析JSON数组？

Question

我刚开始想做一个可以和Facebook互动的Google App引擎应用。我的编程经验主要是在Matlab里做一些数字计算，这种语言比较高级，很多真正的程序员甚至都没听说过。我正在尝试扩展Facebook提供的一个示例，具体可以在这里找到。目前为止，我尝试添加的唯一功能就是读取用户的朋友列表。我在下面的代码中添加的行前面加了注释。代码成功地从Facebook加载了用户信息，我可以访问各种用户属性并显示出来。然而，我尝试添加的朋友属性总是一个空列表。我觉得问题在于，像名字和ID这样的属性是可以像Python字符串那样处理的JSON字符串，但graph.get_connections返回的是一个包含JSON对象的数组，作为朋友列表。我认为我应该把这个JSON数组转换成Python字典，但我不知道该怎么做。当然，我也可能完全错了。

如果能给我一些建议，告诉我怎么把用户的朋友列表转成我可以操作的Python列表，我会非常感激。

谢谢，

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"]:
                    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()

software development google app engine facebook api api integration programming concepts json parsing data manipulation user data retrieval

如何在加载Facebook好友到Google App Engine示例时解析JSON数组？

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