Python Exception in thread Thread-1 (most likely raised during interpreter shutdown)?

Question

My friend and I have been working on a large project to learn and for fun in python and PyGame. Basically it is an AI simulation of a small village. we wanted a day/night cycle so I found a neat way to change the color of an entire surface using numpy (specifically the cross-fade tutorial) - http://www.pygame.org/docs/tut/surfarray/SurfarrayIntro.html

I implemented it into the code and it WORKS, but is extremely slow, like < 1 fps slow. so I look into threading (because I wanted to add it eventually) and found this page on Queues - Learning about Queue module in python (how to run it)

I spend about 15 minutes making a basic system but as soon as I run it, the window closes and it says

Exception in thread Thread-1 (most likely raised during interpreter shutdown):

EDIT: This is literally all it says, no Traceback error

I don't know what I am doing wrong, but I assume I am missing something simple. I added the necessary parts of the code below.

q_in = Queue.Queue(maxsize=0)

q_out = Queue.Queue(maxsize=0)

def run():    #Here is where the main stuff happens
    #There is more here I am just showing the essential parts
    while True:
        a = abs(abs(world.degree-180)-180)/400.

        #Process world
        world.process(time_passed_seconds)

        blank_surface = pygame.Surface(SCREEN_SIZE)
        world.render(blank_surface)    #The world class renders everything onto a blank surface
        q_in.put((blank_surface, a))
        screen.blit(q_out.get(), (0,0))

def DayNight():
    while True:
        blank_surface, a = q_in.get()
        imgarray = surfarray.array3d(blank_surface)  # Here is where the new numpy       stuff starts (AKA Day/Night cycle)
        src = N.array(imgarray)
        dest = N.zeros(imgarray.shape)
        dest[:] = 20, 30, 120
        diff = (dest - src) * a
        xfade = src + diff.astype(N.int)

        surfarray.blit_array(blank_surface, xfade)
        q_out.put(blank_surface)
        q_in.task_done()

def main():
    MainT = threading.Thread(target=run)
    MainT.daemon = True
    MainT.start()

    DN = threading.Thread(target=DayNight)
    DN.daemon = True
    DN.start()

    q_in.join()
    q_out.join()

If anyone could help it would be greatly appreciated. Thank you.

user_8821437 · Answer

(1) This works for me. SOURCE: https://realpython.com/intro-to-python-threading/#starting-a-thread

(2) I use daemon

import logging
import threading
import time

def thread_function(name):
    logging.info("Thread %s: starting", name)
    time.sleep(2)
    logging.info("Thread %s: finishing", name)

if __name__ == "__main__":
    format = "%(asctime)s: %(message)s"
    logging.basicConfig(format=format, level=logging.INFO,
                        datefmt="%H:%M:%S")

    threads = list()
    for index in range(3):
        logging.info("Main    : create and start thread %d.", index)
        x = threading.Thread(target=thread_function, args=(index,) ,  daemon=True)
        threads.append(x)
        x.start()

    for index, thread in enumerate(threads):
        logging.info("Main    : before joining thread %d.", index)
        thread.join()
        logging.info("Main    : thread %d done", index)

Python Exception in thread Thread-1 (most likely raised during interpreter shutdown)?

2 Answers