A python script that sends g-code to Arduino loaded with GRBL2 arduino

test GRBL.py

import serial
import time

ser=serial.Serial('COM5', 9600)
counter = 0

ser.write('g0x0\n')

time.sleep(1)

time.sleep(1)

while counter <50:
    current = str(int(counter))
    print current
    a = 'g0x' + current + '\n'
    ser.write(a)
    print a
    time.sleep(2.5)
    counter += 2.5

time.sleep(2.5)

while counter >.2:
    current = str(int(counter))
    print current
    a = 'g0x' + current + '\n'
    ser.write(a)
    print a
    time.sleep(2.5)
    counter -= 2.5

time.sleep(2.5)
time.sleep(2.5)
ser.write('g0x0\n')

time.sleep(5)

ser.write('g0x0\n')

time.sleep(1)

time.sleep(1)

while counter <50:
    current = str(int(counter))
    print current
    a = 'g0x' + current + '\n'
    ser.write(a)
    print a
    time.sleep(2.5)
    counter += 1

time.sleep(2.5)

while counter >.2:
    current = str(int(counter))
    print current
    a = 'g0x' + current + '\n'
    ser.write(a)
    print a
    time.sleep(2.5)
    counter -= 1

time.sleep(2.5)
time.sleep(2.5)
ser.write('g0x0\n')

time.sleep(5)