项目需求:
秒表Timer,具有启动、停止、重设的功能。请你实现该秒表Timer类的全部功能。提示:注意Timer初始化时的参数,并考虑状态的处理。注意:请勿修改main方法中的调用。
import timeclass Timer: def __init__(self, perf_counter=time.perf_counter): self.time = 0.0 self.counter = perf_counter self._start = None def start(self): #No.1 #开始写代码,请实现秒表启动时所需进行的操作 if self._start is not None: #end_code def end(self): #No.2 #开始写代码,请实现秒表停止时所需进行的操作 if self._start is None: #end_code def reset(self): #No.3 #开始写代码,请实现秒表重设时所需进行的操作 self.time = #end_code @property def running(self): return self._start is not None def __enter__(self): self.start() return self def __exit__(self, *args): self.end() if __name__ == '__main__': def count(n): while n > 0: n -= 1 t = Timer() t.start() count(1000000) t.end() print(t.time) t.reset() t.start() count(1000000) t.end() print(t.time)