魔术方法的简单定制

import time as t

class MyTimer():
    def __init__(self):
        self.unit = ['Year ','Month ','Day ','Hour ','Minute ','Second']
        self.prompt = "hasn't started,use start() first"
        self.lasted = []
        self.begin = 0
        self.end = 0
        
    def __str__(self):
        return self.prompt
    __repr__ = __str__

    def __add__(self,other):
        prompt = "Both lasted :"
        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

    #start timing
    def start(self):
        self.begin = t.localtime()
        self.prompt = "Use the stop() to stop"
        print("start...")

    #stop timing
    def stop(self):
        if not self.begin:
            print('Use start() first')
        else:
            self.end = t.localtime()
            self._calc()
            print("stoped!")

    #count time
    def _calc(self):
        self.lasted = []
        self.prompt = "All lasted :"
        for index in range(6):
            self.lasted.append(self.end[index] - self.begin[index])
            self.prompt += (str(self.lasted[index]) + self.unit[index])

        #init for next turn
        self.begin = 0
        self.end = 0



```  
运行结果：