计时器

import time as t

class MyTimer():
    def __init__(self):
        self.unit = ['年','月','天','小时','分钟','秒']
        self.prompt = '未开始计时'
        self.lasted = []
        self.begin = 0
        self.end = 0
    def __str__(self):
        return self.prompt
    __repr__ = __str__
    def __add__(self, other):
        prompt = '总共运行了'
        result = []
        for index in range(6):
            result.append(self.lasted[index] + other.lasted[index])
            if result[index]:
                prompt += (str(result[index]) + self.unit[index])
        return prompt
    #开始计时
    def start(self):
        self.begin = t.localtime()
        self.prompt = '提示：请先调用stop()停止计时'
        print('计时开始。。。')
    #停止计时
    def stop(self):
        if not self.begin:
            print('提示：请先调用start()进行计时')
        else:
            self.end = t.localtime()
            self._calc()
            print('计时结束！')

    #内部方法，计算运行时间
    def _calc(self):
        self.lasted = []
        self.prompt = '总共运行了'
        for index in range(6):
            self.lasted.append(self.end[index] - self.begin[index])
            if self.lasted[index]:
                self.prompt += str(self.lasted[index]) + self.unit[index]
        #为下一轮计时初始化变量
        self.begin = 0
        self.end = 0
        #print(self.prompt)