Class ReusableTimer

example_code/item_109.py:76–87

import threading

class ReusableTimer:
    def __init__(self):
        self.timer = None

    def countdown(self, duration, callback):
        self.end()
        self.timer = threading.Timer(duration, callback)
        self.timer.start()

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


print("Example 3")