#!/usr/bin/env python

import time
import serial
ser = serial.Serial(
    port='/dev/ttyACM0',
    baudrate = 9600,
    parity=serial.PARITY_NONE,
    stopbits=serial.STOPBITS_ONE,
    bytesize=serial.EIGHTBITS,
    timeout=1
)
counter=0

while 1:
    park_status = ser.readline()
    try:
        if park_status != prev_status:
            if b'1' in park_status:
                print("parking reserved.\n")
            elif b'0' in park_status:
                print("parking not reserved.\n")
    except NameError:
        print("**Not already prev variable.\n")
    prev_status = park_status