import time
import RPi.GPIO as GPIO
print "hello world"

GPIO.setmode(GPIO.BCM)
GPIO.setup(18, GPIO.OUT)
number = 0.001
timer = 200
while 1:

        while timer != 0 :
                GPIO.output(18, True)
                time.sleep(number)
                GPIO.output(18, False)
                time.sleep(number)
                timer = timer - 1
        timer = 200
        time.sleep(0.3)