log.py

import paho.mqtt.client as mqtt
import csv
import json
import time

mqtt_host = "127.0.0.1"
mqtt_port = "1883"
mqtt_user = "/vendingmachine:fahmi"
mqtt_pass = "12345678"
vending_id = "VMTB001"
file_csv = "logs.csv"
file_mode = "ab"

def on_connect(client, userdata, flags, rc):
    global loop_flag
    print ("Connected with rc: " + str(rc))
    client.subscribe("vending/machine/" + vending_id + "/logs")

def on_message(client, userdata, msg):
    print ("get data")
    data = json.loads(msg.payload)
    print (msg.payload)
    print ("encode to json")
    csv_file = open(file_csv, file_mode)
    writelog = csv.writer(csv_file)
    print ("open file")
    count = 0
    for item in data:
        print ("write value to csv")
        writelog.writerow(item.values())
    csv_file.close()

def run():
    client = mqtt.Client()
    client.on_connect = on_connect
    client.on_message = on_message
    client.username_pw_set(mqtt_user, mqtt_pass)
    client.connect(mqtt_host, mqtt_port, 60)
    client.loop_forever()

try:
    run()
except:
    print("connection failed")
    time.sleep(45)
    run()