GPIO-封装-西湖歌舞几时休

对系统的GPIO库进行封装，对上层屏蔽直接设置IO口的操作，只暴露high和low两个接口

#!/usr/bin/python3 
#encoding=utf-8

import time

try: 
    import RPi.GPIO as _GPIO 
except Exception as e: 
    class _GPIO(): 
        OUT = 0 
        LOW = 0 
        HIGH = 0 
        BOARD = 0

        @staticmethod 
        def setup(index, inout): 
            pass

        @staticmethod 
        def output(index, high): 
            pass

        @staticmethod 
        def setmode(x): 
            pass

class GPIO(object): 
    BCM     = _GPIO.BCM 
    BOARD   = _GPIO.BOARD 
    LOW     = _GPIO.LOW 
    HIGH    = _GPIO.HIGH

    def __init__(self, index, inout=_GPIO.OUT): 
        self.__index = index 
        _GPIO.setup(self.__index, inout, initial = GPIO.LOW)

    def high(self): 
        _GPIO.output(self.__index, GPIO.HIGH)

    def low(self): 
        _GPIO.output(self.__index, GPIO.LOW)

    @staticmethod 
    def init(mode): 
        _GPIO.setmode(mode)

    @staticmethod 
    def cleanup(): 
        _GPIO.cleanup()

def main(): 
    GPIO.init(GPIO.BCM) 
    led = GPIO(21) 
    led.high() 
    time.sleep(1) 
    GPIO.cleanup()

if '__main__' == __name__: 
    main()