Python遅延シャットダウン

# -*- coding:utf8 -*-
# This program is created for auto power off my windows :)
# Author: fengxing
# Data: 2011-8-30

import sys
import os
import time
from datetime import datetime

def Usage():
	print 'Usage:', os.path.basename(__file__), '[-t HH:MM] | delata{h|m}'

# shutdown computer after time_diff seconds
def shutdown(time_diff):
	assert time_diff > 0
	time.sleep(time_diff)
	os.system('shutdown -s -f -t 60')

def main():
	timeto = -1;
	if len(sys.argv) == 2:
		dat = sys.argv[1]
		if dat.endswith('h'):
			timeto = int(dat[0:-1]) * 3600
		elif sys.argv[1].endswith('m'):
			timeto = int(dat[0:-1]) * 60
	elif len(sys.argv) == 3 and sys.argv[1] == '-t':
		tm = sys.argv[2].split(':')
		if len(tm) == 2:
			now = datetime.today()
			ends = datetime(now.year, now.month, now.day,
					int(tm[0]), int(tm[1]))
			timeto = (ends - now).seconds	#don't care about day
	
	if timeto < 0:
		Usage()
		exit(1)
	
	print 'sleep', timeto
	shutdown(timeto)

if __name__ == '__main__':
	main()