Simple way to know if you have new messages on reddit

Default.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from urllib.request import Request, build_opener, HTTPCookieProcessor, HTTPHandler
from urllib.parse import urlencode
from http.cookiejar import CookieJar
import json

url = "http://www.reddit.com/"

data = bytes(urlencode({
  'user': 'login',
  'rem': False,
  'passwd': 'passwd'
}),'utf8')


#Create a CookieJar object to hold the cookies
cj = CookieJar()
#Create an opener to open pages using the http protocol and to process cookies.
opener = build_opener(HTTPCookieProcessor(cj), HTTPHandler())

#create a request object to be used to get the page.
req = Request(url+"api/login",data)
opener.open(req)

req = Request(url+"message/unread.json")
result = opener.open(req).read()

messages = json.loads(result.decode('utf8'))

messages = messages['data']['children']

if len(messages):
    print("Nouveaux messages")
else:
    print("Pas de nouveau messages")