timer.py

timer.py

'''
Date: 2022-06-01 13:49:12
LastEditors: ibegyourpardon
LastEditTime: 2022-06-01 13:52:47
FilePath: /undefined/Users/feiandxs/Downloads/timer.py
'''
import time

class TimerError(Exception):
    """
    A custom exception class that is raised when the timer has been
    stopped.
    """
    pass


class Timer:
    def __init__(self):
        self.start_time = None
        self.stop_time = None

    def start(self):
        """Start a new timer"""
        if self.start_time:
            raise TimerError("Timer has already been started,Use .stop() to stop it")

        self.start_time = time.perf_counter()

    def stop(self):
        """Stop the timer ,and report the elapsed time"""
        if not self.start_time:
            raise TimerError("Timer has not been started,Use .start() to start it")
        elapsed_time = time.perf_counter() - self.start_time
        self.start_time = None
        print(f"Elapsed time: {elapsed_time:0.4f} seconds")