监控服务器cpu使用率在python怎么实现？

def cpu():
    while True:
        time.sleep(1)
        cpu_liyonglv = psutil.cpu_percent()
        print "当前cpu利用率：\033[1;31;42m%s%%\033[0m"%cpu_liyonglv
        if cpu_liyonglv >15.0:
            baojing()

def baojing():
    i = 0
    while i < 10 :
        i += 1
        time.sleep(0.5)
        winsound.PlaySound("ALARM8",winsound.SND_ALIAS)
cpu()