this mqtt send mssg to mutiple unique subscriber

main.py

+"""
+Creates multiple Connections to a broker 
+and sends and receives messages. Support SSL and Normal connections
+uses the loop_start and stop functions just like a single client
+Shows number of thread used
+"""
+import paho.mqtt.client as mqtt
+import time
+import json
+import threading
+import logging
+
+clients = [
+    {"broker": "192.168.0.220", "port": 1883, "name": "blank", "sub_topic": "patient_1", "pub_topic": "doctor_1"},
+    {"broker": "192.168.0.220", "port": 1883, "name": "blank", "sub_topic": "patient_2", "pub_topic": "doctor_2"}
+]
+nclients = len(clients)
+message = "test message"
+
+out_queue = []  # use simple array to get printed messages in some form of order
+
+
+##########
+def multi_loop(nclients, flag=True):
+    while flag:
+        for i in range(nclients):
+            client = clients[i]
+            client.loop(0.01)
+
+
+#########
+
+def on_log(client, userdata, level, buf):
+    print(buf)
+
+
+def on_message(client, userdata, message):
+    time.sleep(1)
+    msg = "message received", str(message.payload.decode("utf-8"))
+    # print(msg)
+    out_queue.append(msg)
+
+
+def on_connect(client, userdata, flags, rc):
+    if rc == 0:
+        client.connected_flag = True  # set flag
+        for i in range(nclients):
+            if clients[i]["client"] == client:
+                topic = clients[i]["sub_topic"]
+                break
+
+        client.subscribe(topic)
+    else:
+        print("Bad connection Returned code=", rc)
+        client.loop_stop()
+
+
+def on_disconnect(client, userdata, rc):
+    pass
+    # print("client disconnected ok")
+
+
+def on_publish(client, userdata, mid):
+    time.sleep(1)
+    print("In on_pub callback mid= ", mid)
+
+
+def Create_connections():
+    for i in range(nclients):
+        cname = "client" + str(i)
+        t = int(time.time())
+        client_id = cname + str(t)  # create unique client_id
+        client = mqtt.Client(client_id)  # create new instance
+        clients[i]["client"] = client
+        clients[i]["client_id"] = client_id
+        clients[i]["cname"] = cname
+        broker = clients[i]["broker"]
+        port = clients[i]["port"]
+        try:
+            client.connect(broker, port)  # establish connection
+        except:
+            print("Connection Fialed to broker ", broker)
+            continue
+
+        # client.on_log=on_log #this gives getailed logging
+        client.on_connect = on_connect
+        client.on_disconnect = on_disconnect
+        # client.on_publish = on_publish
+        client.on_message = on_message
+        while not client.connected_flag:
+            client.loop(0.01)  # check for messages
+            time.sleep(0.05)
+
+
+mqtt.Client.connected_flag = False  # create flag in class
+no_threads = threading.active_count()
+print("current threads =", no_threads)
+print("Creating  Connections ", nclients, " clients")
+
+Create_connections()
+t = threading.Thread(target=multi_loop, args=(nclients, True))  # start multi loop
+t.start()
+print("All clients connected ")
+time.sleep(5)
+#
+count = 0
+no_threads = threading.active_count()
+print("current threads =", no_threads)
+print("Publishing ")
+Run_Flag = True
+# this is a bad example when using the loop() call as the while loop
+# as lots or sleep calls
+try:
+    while Run_Flag:
+        i = 0
+        for i in range(nclients):
+            client = clients[i]["client"]
+            pub_topic = clients[i]["pub_topic"]
+            counter = str(count).rjust(6, "0")
+            msg = "client " + str(i) + " " + counter + "XXXXXX " + message
+            if client.connected_flag:
+                client.publish(pub_topic, msg)
+                time.sleep(0.1)
+                print("publishing client " + str(i))
+            i += 1
+        time.sleep(10)  # now print messages
+        print("queue length=", len(out_queue))
+        for x in range(len(out_queue)):
+            print(out_queue.pop())
+        count += 1
+        # time.sleep(5)#wait
+except KeyboardInterrupt:
+    print("interrupted  by keyboard")
+
+# client.loop_stop() #stop loop
+for client in clients:
+    client.disconnect()
+multi_loop(flag=False)  # stop loop
+# allow time for allthreads to stop before existing
+time.sleep(10)