app.py

import paho.mqtt.client as mqtt
## receiving here
TOPIC = "mqtt/kubernetes"
BROKER_ADDRESS = "broker.hivemq.com"
PORT = 1883
import re
def calulcate_result(numbers):
    num = re.findall('[0-9]+',numbers)
    result = int(num[0]) + int(num[1])
    return result

def on_message(client, userdata, message):
    msg = str(message.payload.decode("utf-8"))
    ##print("message received:", msg)
    print("result of these numbers:", calulcate_result(msg))
    ##print("message topic ", message.topic)

def on_connect(client, userdata, flags, rc):
    print("Connected to MQTT Broker: " + BROKER_ADDRESS)
    client.subscribe(TOPIC)

if __name__ == "__main__":
    client = mqtt.Client()
    client.on_connect = on_connect
    client.on_message = on_message

    client.connect(BROKER_ADDRESS,PORT, 60)

    client.loop_forever()