class RandomThread(Thread):
    def __init__(self):
        self.delay = 1
        super(RandomThread, self).__init__()

    def randomNumberGenerator(self):
        """
        Generate a random number every 1 second and emit to a socketio instance (broadcast)
        Ideally to be run in a separate thread?
        """
        #infinite loop of magical random numbers
        print("Making random numbers")
        while not thread_stop_event.isSet():
            number = round(random()*10, 3)
            print(number)
            socketio.emit('newnumber', {'number': number}, namespace='/test')
            sleep(self.delay)

    def run(self):
        self.randomNumberGenerator()

$(document).ready(function() {
  //connect to the socket server.
  var socket = io.connect('http://' + document.domain + ':' + location.port + '/test');
  var numbers_received = [];


  //receive details from server
  socket.on('newnumber', function(msg) {
   .....
  });

//CHART
        Plotly.plot('chart',[{
            y:[numbers_received[1]],
            type:'line'
            }]);

            console.log('TEST' + numbers_received[0]);

            var cnt = 0;
            setInterval(function(){
            Plotly.extendTraces('chart',{ y:[[numbers_received[0]]]}, [0]);

            cnt++;

            if(cnt >10000000) {
                Plotly.relayout('chart',{
                    xaxis: {
                        range: [cnt-9,cnt]
                        }
                    });
                }
        },15);

    });