Why is "Subscribing to topic topic/test" printed in console log before connect message?

[Spencer Du]

Hi 

I have code for publish and subscribe over mqtt. In the console log I have "Subscribing to topic topic/test" printed before connect message why is this? I want to this to be printed after the connect message. How do I fix this problem. Please run gui.py to test.

gui.py

import paho.mqtt.client as mqtt
from mqtt import *
import json
import time

client = mqtt.Client()
client.connect("broker.hivemq.com",1883,60)
client.on_connect = on_connect
client.on_message = on_message

client.loop_start()
print("Subscribing to topic", "topic/test")
client.subscribe("topic/test")
client.publish("topic/test", "Hello world!")
time.sleep(1)
client.loop_stop()

mqtt.py

import paho.mqtt.client as mqtt

def on_connect(client, userdata, flags, rc):
    print("Connected with result code "+str(rc))

def on_message(client, userdata, msg):
    if msg.payload.decode() == "Hello world!":
        print("Yes!")

Thanks
Spencer