豆瓣OAuth2用户认证登录， Flask应用。

douban_user_login.py

from sqlalchemy.exc import IntegrityError
from flask import g, request, session, redirect, flash
import urllib
import urllib2

from app import models

@app.route('/douban/login')
def get_auth_code():
	return redirect("https://www.douban.com/service/auth2/auth?client_id=0fb837361a070e2d2f28a5a24e152a87&redirect_uri=https://douping.sinaapp.com/auth&response_type=code")

@app.route('/auth')
def auth():
	"""
		Douban OAuth2 authorization 
		Get the auth code and retrive the user info 
	"""
	if request.args.has_key('error'):
		return redirect("http://douping.sinaapp.com")
	
	auth_code = request.args['code']

	params = urllib.urlencode({'client_id': '0fb837361a070e2d2f28a5a24e152a87', 
							   'code':auth_code,
	 						   'client_secret':'########', 
	 						   'redirect_uri':'http://douping.sinaapp.com',
	 						   'grant_type': 'authorization_code'
	})
	
	try:
		f = urllib.urlopen("https://www.douban.com/service/auth2/token", params)
	except urllib2.URLError as e:
		flash(e.reason)
		return redirect("http://douping.sinaapp.com")

	content = json.loads(f.read())
	#POST
	header = {"Authorization": "Bearer " + content["access_token"]}
	req = urllib2.Request(url = "https://api.douban.com/v2/user/~me", headers = header)
	try:
		result = json.loads(urllib2.urlopen(req).read())
	except urllib.URLError as e:
		return redirect("http://douping.sinaapp.com")

	user = models.User.query.filter_by(douban_id = result['id']).first()

	if not user:
		if result['avatar'].split('/')[-1] != 'user_normal.jpg':
			avatar = "http://img3.douban.com/icon/ul" + result['avatar'].split('/')[-1].split('u')[-1]
		else:
			avatar = result['avatar']
		
		try:
			user = models.User(result['id'], result['name'], avatar, result['alt'])
			db.session.add(user)
			db.session.commit()
		except IntegrityError:
			db.session.rollback()
			flash('Database error.')
			return redirect("http://douping.sinaapp.com")
	
	session['user_id'] = user.id
	return redirect("http://douping.sinaapp.com")