在Websockets上发送JSON

我有一个简单的Python tornado Websockets服务器,从JavaScript客户端接收消息。我试图发送JSON数据,我找到的唯一解决方案是将JSON对象转换为字符串JSON,发送它,另一方面通过服务器将字符串解析回JSON。这是我的Json文件:

{
  "events": [
    {
      "id": 0,
      "new": {
        "description": "blabla bla keyyys",
        "keys": [
          "keyyys",
          "key "
        ],
        "start": "2.000000",
        "end": "7.000000",
        "priority": "normal"
      }
    },
    {
      "id": 1,
      "new": {
        "description": "anything key ",
        "keys": [
          "keyyys",
          "key "
        ],
        "start": "0.761077",
        "end": "10.026667",
        "priority": "high"
      }
    }
  ]
}

在发送之前,我在Json中添加了另一个元素:

var messageValue = {}; 
var sendings;
messageValue["messageType"] = "mainfest";
$.getJSON("file.json", function(json) {
    messageValue["data"]= json;
    console.log(messageValue);
    sendings =  jsonToStringConvertor(messageValue);
    });

var socket = new WebSocket('ws://localhost:9000/');

socket.onopen = function(event){
    socket.send(sendings);
}

.

function jsonToStringConvertor(obj)
{
var re = JSON.stringify(obj);
return re;
}

我可以从服务器接收消息并打印出来:

到目前为止很好。但是当我试图像这样解析回Json时

JsonFormattedMessage = json.loads(message)[0]

我得到了这个错误:

ERROR:tornado.application:Uncaught exception in /
Traceback (most recent call last):
  File "/usr/local/lib/python3.4/dist-packages/tornado/websocket.py", line 494, in _run_callback
    result = callback(*args, **kwargs)
  File "index.py", line 27, in on_message
    JsonFormattedMessage = json.loads(message)[0]
KeyError: 0