Semaphore

Components.py

import RPi.GPIO as GPIO
import time

class LED:
    def __init__(self,gpio,pin):
        gpio.setmode(GPIO.BCM)
        gpio.cleanup(pin)
        gpio.setup(pin,GPIO.OUT)
        self.__gpio = gpio
        self.__pin = pin

    def on(self):
        self.__gpio.output(self.__pin,True)

    def off(self):
        self.__gpio.output(self.__pin,False)

class Semaphore:
    def __init__(self,gpio,red_pin,yellow_pin,green_pin):
        gpio.setmode(GPIO.BCM)
        self._led_red = LED(gpio,red_pin)
        self._led_yellow = LED(gpio,yellow_pin)
        self._led_green = LED(gpio,green_pin)

    def reset(self):
        self._led_red.off()
        self._led_yellow.off()
        self._led_green.off()

    def __led(self,color,led_time):
        led = getattr(self,'_led_{0}'.format(color))
        if isinstance(led,LED):
            led.on()
            time.sleep(led_time)
            led.off()

    def start(self,red_time,yellow_time,green_time):
        while True:
            self.__led('red',red_time)
            self.__led('yellow',yellow_time)
            self.__led('green',green_time)

main.py

import RPi.GPIO as pins
from components import Semaphore

s = Semaphore(pins,red_pin,yellow_pin,green_pin)
s.start(10,2,10)