7-TrafficLights-solution.py 文件源码

def startwalking():
    # Make the buzzer buzz on and off, half a second of
    # sound followed by half a second of silence
    print("Start walking")
    count = 1
    while count <= 4:
        print("Beep")
        buzzer.on()
        time.sleep(0.5)
        buzzer.off()
        time.sleep(0.5)
        count += 1


# Turn the buzzer off and wait for 2 seconds
# (If you have a second green 'pedestrian' LED, make it flash on and
# off for the two seconds)