Stopping a python thread running an Infinite Loop

Question

I am new to python programming. I am trying to make a GUI with stoppable threads. I borrowed some code from https://stackoverflow.com/a/325528

class MyThread(threading.Thread):
    """Thread class with a stop() method. The thread itself has to check
    regularly for the stopped() condition."""

    def __init__(self, *args, **kwargs):
        super(MyThread, self).__init__(*args, **kwargs)
        self._stop = threading.Event()

    def stop(self):
        self._stop.set()

    def stopped(self):
        return self._stop.isSet()

I have function which creates a thread for another function in another class that runs an infinite loop.

class MyClass :

    def clicked_practice(self):

        self.practicethread = MyThread(target=self.infinite_loop_method)
        self.practicethread.start()

    def infinite_loop_method()
        while True :
            // Do something


    #This doesn't seem to work and I am still stuck in the loop

    def infinite_stop(self)
        if self.practicethread.isAlive():
        self.practicethread.stop()

I want to create a method to stop this thread . What's happening here?

Answer 1

I think you missed the 'The thread itself has to check regularly for the stopped() condition' bit of that documentation.

Your thread needs to run like this:

while not self.stopped():
    # do stuff

rather than while true. Note that it is still only going to exit at the 'start' of a loop, when it checks the condition. If whatever is in that loop is long-running, that may cause unexpected delays.