Python timer定时器两种常用方法解析

#! /usr/bin/python3
#! -*- conding: utf-8 -*-
import threading
import time
def fun_timer():
  print(time.strftime('%Y-%m-%d %H:%M:%S'))
  global timer
  timer = threading.Timer(2,fun_timer)
  timer.start();
timer = threading.Timer(1,fun_timer)
timer.start();
time.sleep(5)
timer.cancel()
print(time.strftime('%Y-%m-%d %H:%M:%S'))

import time

class TimerError(Exception):
  """A custom exception used to report errors in use of Timer class"""

class Timer:
  def __init__(self):
    self._start_time = None

  def start(self):
    """Start a new timer"""
    if self._start_time is not None:
      raise TimerError(f"Timer is running. Use .stop() to stop it")

    self._start_time = time.perf_counter()

  def stop(self):
    """Stop the timer, and report the elapsed time"""
    if self._start_time is None:
      raise TimerError(f"Timer is not running. 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")