Data stream calculations

Hello, I’m a complete beginner at programming. I have problem with calculations with data from Binanace stream. For example how can I calculate “high” - “low” like in line 24 in my example code?

Thanks.

import websocket, datetime, pprint, json, config
import numpy as np


from binance.client import Client
client = Client(config.api_key, config.api_secret, testnet=True)

symbol = 'btcusdt'




def on_message(ws, message):
    print()
    print(str(datetime.datetime.now()) + ": ")
    #print(message) 
    json_message = json.loads(message)
  # pprint.pprint(json_message)

    high = json_message['h']
    low = json_message['l']
    print(high)
    print(low)
    range = high - low
    print(range)


    if high > low:
        print("Is higher")

    else:
        print("Is not higher")

def on_error(ws, error):
    print(error)

def on_close(ws, close_msg):
    print("### closed ###" + close_msg)

def streamKline(symbol):
    websocket.enableTrace(False)
    socket = f'wss://stream.binance.com:9443/ws/{symbol}@ticker'


    ws = websocket.WebSocketApp(socket,
                                on_message=on_message,
                                on_error=on_error,
                                on_close=on_close)
    ws.run_forever()

streamKline(symbol)
  "h": "0.0025",      // High price
  "l": "0.0010",      // Low price

I think you need to convert the string to float for the calculation to work.

Thanks, its working