Reads the temperature from android and writes a json file

readTemp.py

import serial
import time
import json
from datetime import datetime

def read_from_serial(serial_device_name):
    ser = serial.Serial(serial_device_name, 9600)
    time.sleep(2)

    b = ser.readline()         # read a byte string
    string_n = b.decode()  # decode byte string into Unicode
    string = string_n.rstrip() # remove \n and \r
    obj = json.loads(string)
    now = datetime.now()
    current_time = now.strftime("%H:%M")
    print("Umidade eh "+str(obj["h"])+" e temperatura eh "+str(obj["t"])+" as " +current_time )

    ser.close()

for i in range(9):
    try:
        read_from_serial('/dev/ttyUSB'+ str(i))
        break
    except:
        continue