def r_oauth(request):
  #授权
  url="https://open/weixin.qq.com/connect/oauth2/authorize"
  redirect_uri="http://pypages.gongchang.com/user/"
  redirect_uri=urllib.quote(redirect_uri)
  return redirect(url.format(app_id,redirect_uri) #format拼接url
def get_userinfo(request):
 #获取用户信息
 code=request.GET.get("code"）
 if not code:
  return HttpResponse("not find code")
 token_url="https://api.weixin.qq.com/sns/oauth2/access_token"
  # 通过code 可以获取到access_token ，但是code 只能获取道一次获取token 的时候可能要刷新，不然会获取不到token
 data=requests.get(token_url.format(app_id,app_secret,code))
 #转为json 格式的字符串
 data=json.loads(data.content.decode("utf-8"))
 #获取access_token
 access_token=data['access_token']
 open_id=data['openid']
 refresh_token=data['refresh_token']
 if not access_token or not open_id:
  return None # 判断是否有token 和open_id
 # 用户的url
 user_url="https://api.weixin.qq.com/sns/userinfo"
 d=requests.get(user_url.format(access_token,open_id)
 d=d.content.decode("utf-8")
 if not d:
  return None
 d=json.loads(d)
 if d.has_key("errcode") and d["errcode"]==40001:
  #token过期解决
  refresh_toekn_url="https://api.weixin.qq.com/sns/oauth2/refresh_token"
  r_d=requests.get(refresh_token_url.format(app_id,refresh_token))
  r_d=json.loads(r_d.content.decode("utf-8"))
  access_token=r_d["access_token"]
  d=requests.get(user_url.format(access_token,open_id))
  d=d.content.decode("utf-8")
  response=HttpResponse(json.dumps(d))
  # 设置cookie 将用户信息保存到cookie里面
  response.set_cookie("userinfo",json.dumps(d),max_age=7 * 24 * 3600) # 设置过期时间7 天
  return response

url(r'^r_oauth/$', views.r_oauth), # 授权 
 url(r'^user/$', views.get_user_info), # 获取用户信息