how to check if a field exist in facebook graph api using python? -

as facebook graph api uses json format show data.i want books name liked friends using python , facebook graph api program stops when of friend have not read book. please give me way check if field exist or not.thanks in advance.

here code :

print name of friends , books liked them. id , access token given user.

import requests import json

base_url = raw_input("enter id : ")

access_token = raw_input("paste here access token : ")

base_url = '6365047697172' access_token = 'caacedeose0cbancfk1kuosp6gzcosmqzc17v1vzcmwra5fw16pks7iuoz2zailizcfnij32rzcvzb7kah0aa6dqludloyzbi6gs30vlzay2jp7zczm0tpbcnermkrpdt2pifxxdscnbzasskypikuxsppkksncemkeugbzb3upxniy4bw0dmkkqeuhqrns5xuxcdynevtyh17pzb09lgzboipw2' base_url = 'https://graph.facebook.com/' + base_url

fields ='friends{books,name}' url = '%s?fields=%s&access_token=%s' % \ (base_url, fields, access_token,)

def get_books(): """ returns list of posts on timeline """

parameters = {'access_token': access_token} r = requests.get(url) result = json.loads(r.text) friends =  result["friends"]  frnd_data = friends["data"] frnd_name in frnd_data:     print frnd_name['name']     frnd_book = frnd_name['books'] #error when there no field name books     f_b_name = frnd_book["data"]     b_name in f_b_name:         print b_name['name'] 

get_books()

if use json module in python, method load (or loads) maps json dictionary. can treat dictionary means can ask if contains value using following code

if field in json:     ... 

i hope helps.