Generic synchronous task queue with concurrency in Python3

synchronous_task_queue.py

from threading import Thread
import queue
import time
import random
import string

class Task(object):
    def __init__(self,*args,**kwargs):
        self.fn = kwargs.pop('fn')
        self.args = args
        self.kwargs = kwargs

    def execute(self):
        self.fn(*self.args,**self.kwargs)

class TaskQueue(object):
    def __init__(self,default_task_function=None):
        self.queue = queue.Queue()
        self.thread = Thread(target=self.worker)
        self.thread.daemon = True
        self.default_task_fn = default_task_function or self._task_fn
        self.thread.start()

    def enqueue(self,*args,**kwargs):
        kwargs.setdefault('fn',self.default_task_fn)
        self.queue.put(Task(*args,**kwargs))

    @staticmethod
    def task_fn(*args,**kwargs):
        raise Exception("No task function defined!  Either override this method or pass a function to the TaskQueue.")

    def worker(self):
        while True:
            task = self.queue.get()
            if task is None:
                self.queue.task_done()
                break
            task.execute()
            self.queue.task_done()

    def finish(self):
        self.queue.put(None)
        self.queue.join()
        self.thread.join()

def main():
    def generate_task_id():
        return ''.join(random.choices(string.ascii_uppercase + string.digits, k=8))

    def task_fn(task_id,wait_time):
        print("task thread: task id %s will sleep %s seconds" % (task_id,wait_time))
        time.sleep(wait_time)
        print("task thread: task id %s has finished." % task_id)

    tq = TaskQueue(default_task_function=task_fn)

    for i in range(10):
        task_id = generate_task_id()
        wait_time = random.randint(1,5)
        print("main thread: enqueuing task ID %s." % task_id)
        tq.enqueue(task_id,wait_time)

    print("main thread: do stuff.")
    for i in range(5):
        main_wait = random.randint(1,3)
        print("main thread: sleeping %s seconds" % main_wait)
        time.sleep(main_wait)
    print("main thread: awaiting task queue to finish...")
    tq.finish()

if __name__ == '__main__':
    main()