计时器在 Python 中停止后无法重新启动 [英] Timer cannot restart after it is being stopped in Python

问题描述

我使用的是 Python 2.7.我有一个计时器，它不断重复计时器回调动作，直到它停止.它使用一个 Timer 对象.问题是它被停止后，无法重新启动.Timer对象代码如下；

I am using Python 2.7. I have a timer that keeps repeating a timer callback action until it has been stopped. It uses a Timer object. The problem is that after it has been stopped, it cannot be restarted. The Timer object code is as follows;

from threading import Timer

class RepeatingTimer(object):
    def __init__(self,interval, function, *args, **kwargs):
        super(RepeatingTimer, self).__init__()
        self.args = args
        self.kwargs = kwargs
        self.function = function
        self.interval = interval

    def start(self):
        self.callback()

    def stop(self):
        self.interval = False       

    def callback(self):
        if self.interval:
            self.function(*self.args, **self.kwargs)
            Timer(self.interval, self.callback, ).start()

要启动定时器，运行下面的代码；

To start the timer, the code below is run;

repeat_timer = RepeatingTimer(interval_timer_sec, timer_function, arg1, arg2)
repeat_timer.start()    

停止定时器，代码为；

repeat_timer.stop() 

停止后，我尝试通过调用 repeat_timer.start() 重新启动计时器，但计时器无法启动.定时器停止后如何重新启动?

After it is stopped, I tried to restart the timer by calling repeat_timer.start() but the timer is unable to start. How can the timer be made to restart after it has been stopped?

谢谢.

推荐答案

这是一个更正的版本:

from __future__ import print_function


from threading import Timer


def hello():
    print("Hello World!")


class RepeatingTimer(object):

    def __init__(self, interval, f, *args, **kwargs):
        self.interval = interval
        self.f = f
        self.args = args
        self.kwargs = kwargs

        self.timer = None

    def callback(self):
        self.f(*self.args, **self.kwargs)
        self.start()

    def cancel(self):
        self.timer.cancel()

    def start(self):
        self.timer = Timer(self.interval, self.callback)
        self.timer.start()


t = RepeatingTimer(3, hello)
t.start()

示例运行:

$ python -i foo.py
>>> Hello World!

>>> Hello World!

>>> t.cancel()

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