Updating realtime data in webpage using flask

Iam trying to make an application which will receive data from tcp server and display realtime data in webpage using flask python.
When iam running the code, iam getting {} as response in Console and no output in webpage

from flask import Flask, jsonify, render_template
import threading
import socket
import json
import time

app = Flask(__name__)

data = {}

@app.route('/sensor_data')
def index():
    global data
    print(data)
    return render_template('sensor_data.html', data=data)
    # return jsonify(data)


def update_data(data):
    global sock
    while True:
        # read data from the TCP socket
        sock.send('A\n'.encode())
        data_str = sock.recv(1024).decode()
        data_str = {'Temperature': data_str[33:38], 'Humidity': data_str[52:57]}
        data_str = json.dumps(data_str)
        # decode JSON data
        new_data = json.loads(data_str)
        # update the data on the webpage
        data.update(new_data)
        print(data)
        # wait for 1 second
        time.sleep(1)

if __name__ == '__main__':
    # establish TCP socket connection
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect(('192.168.56.1', 35000))
    # start updating data
    update_data_thread = threading.Thread(target=update_data, args=(data,))
    update_data_thread.start()
    # start the Flask server
    app.run(debug=True)
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>SocketIO Data</title>
  </head>
  <body>
    <h1>SocketIO Data</h1>
    <p>Temperature: {{ data.Temperature }} *C</p>
    <p>Humidity: {{ data.Humidity }} %H</p>
  </body>
</html>