Resettable timer in python repeats until cancelled

问题

I have copied the code from this webaddress http://code.activestate.com/recipes/577407-resettable-timer-class-a-little-enhancement-from-p/

To create a resettable timer, and it works nicely but once it has finished it ends. I would like to start it again but I'm new and couldn't work out how to do it.

I tired creating a new instance of itself at the bottom of the run() function after the line:

print "Time: %s - timer finished!" % time.asctime()

but python didn't seem to like it.

The copy pasted code created by Eddy Jacob is this :

from threading import Thread, Event, Timer
import time

def TimerReset(*args, **kwargs):
    """ Global function for Timer """
    return _TimerReset(*args, **kwargs)


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

    t = TimerReset(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()
        self.resetted = True

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

    def run(self):
        print "Time: %s - timer running..." % time.asctime()

        while self.resetted:
            print "Time: %s - timer waiting for timeout in %.2f..." % (time.asctime(), self.interval)
            self.resetted = False
            self.finished.wait(self.interval)

        if not self.finished.isSet():
            self.function(*self.args, **self.kwargs)
        self.finished.set()
        print "Time: %s - timer finished!" % time.asctime()

    def reset(self, interval=None):
        """ Reset the timer """

        if interval:
            print "Time: %s - timer resetting to %.2f..." % (time.asctime(), interval)
            self.interval = interval
        else:
            print "Time: %s - timer resetting..." % time.asctime()

        self.resetted = True
        self.finished.set()
        self.finished.clear()

I ran my timer using :

tim = TimerReset(10, AddBlank)
tim.start()

The function AddBlank does something but I would like the timer to be called again but only after it has ended. Really appreciate help with this, I know copying code without understanding it is bad practice but I really just wanted a simple resettable timer to call a function repeatedly unless reset and this almost does that.

回答1:

Change the run function to:

def run(self):
    while not self.finished.isSet():
        print "Time: %s - timer running..." % time.asctime()

        self.resetted = True
        while self.resetted:
            print "Time: %s - timer waiting for timeout in %.2f..." % (time.asctime(), self.interval)
            self.resetted = False
            self.finished.wait(self.interval)

        if not self.finished.isSet():
            self.function(*self.args, **self.kwargs)
    print "Time: %s - timer finished!" % time.asctime()

This will cause it to run indefinitely until finished is set.

来源：https://stackoverflow.com/questions/15651931/resettable-timer-in-python-repeats-until-cancelled