Processing Data from an MQTT stream using Paho-MQTT

I have a microcontroller that is streaming data to a MQTT broker and also a python script using the Paho-MQTT package to subscribe to the topic that my microcontroller is publishing to. In all of the examples that I see with Paho-MQTT the script is constantly looping the client as seen below:

def subscribe(client: mqtt_client):
    def on_message(client, userdata, msg):
        messageQueue = msg.payload.decode()
        print(messageQueue)

    client.subscribe(topic)
    client.on_message = on_message


def run():
    client = connect_mqtt()
    subscribe(client)
    client.loop_forever()

run()

The problem that I'm running into is that I need to actually process the data that is being sent and since loop_forever is a blocking process, I can't ever break through to do anything with the data. I've looked into multi-threading since it seemed like that would allow me to run both the MQTT client and the processing simultaneously, but it seems like there is no way to transfer variables between threads. Is there something that I'm doing wrong, or how should I manage this?

Thanks in Advance!

I've looked into multi-threading since it seemed like that would allow me to run both the MQTT client and the processing simultaneously, but it seems like there is no way to transfer variables between threads. I've also tried stopping the loop to process and then restarting the loop but that also hasn't worked in that it never gets to the parts of my code where I process the data, it just forever is listening.

source https://stackoverflow.com/questions/75138936/processing-data-from-an-mqtt-stream-using-paho-mqtt