Is there any way to extend threading.Timer in python

Question

For threading.Timer Object, is there any way to update the timer time after calling start method ?

for example

timer = threading.Timer(5, function)
timer.start()
#after calling start method, i want to extend the timer time before expired.

as i looked through the document of threading.Timer, there isn't way.

so do i have to call cancel method then call again start method?

Answer 1

The Timer object is really quite simple:

def Timer(*args, **kwargs):
    return _Timer(*args, **kwargs)

class _Timer(Thread):
    """Call a function after a specified number of seconds:

    t = Timer(30.0, f, args=[], kwargs={})
    t.start()
    t.cancel() # stop the timer's action if it's still waiting
    """

    def __init__(self, interval, function, args=[], kwargs={}):
        Thread.__init__(self)
        self.interval = interval
        self.function = function
        self.args = args
        self.kwargs = kwargs
        self.finished = Event()

    def cancel(self):
        """Stop the timer if it hasn't finished yet"""
        self.finished.set()

    def run(self):
        self.finished.wait(self.interval)
        if not self.finished.is_set():
            self.function(*self.args, **self.kwargs)
        self.finished.set()

It's just waiting calling wait with a timeout on a threading.Event object, then either runs the provided method or exits if cancel was called. You could implement your own version of Timer that supports extending the wait, but the default one definitely doesn't support it.