计算某时间戳与当前时间的时间差，输出格式为天时分秒

def timediff_to_str(timestamp):
    onlineTime = datetime.datetime.fromtimestamp(timestamp)
    localTime = datetime.datetime.now()
    result = localTime - onlineTime
    hours = int(result.seconds / 3600)
    minutes = int(result.seconds % 3600 / 60)
    seconds = result.seconds%3600%60
    return "{0}天{1}时{2}分{3}秒".format(result.days,hours,minutes,seconds)