Issue with sys.exit() in pygame

Question

I am learning to use Pygame, and when I use sys.exit(), I run into a problem. Here is the code:

import pygame, sys,os
from pygame.locals import * 

pygame.init() 

window = pygame.display.set_mode((468, 60)) 
pygame.display.set_caption('Game') 
screen = pygame.display.get_surface() 

file_name = os.path.join("data","image.bmp")

surface = pygame.image.load(file_name)

screen.blit(surface, (0,0)) 
pygame.display.flip() 

def input(events): 
   for event in events: 
      if event.type == QUIT: 
         sys.exit(0) 
      else: 
         print event 

while True: 
   input(pygame.event.get()) 

It's really just the code from the pygame tutorial. The problem occurs when I actually try to exit, regardless of what event I try to use to sys.exit().

Traceback (most recent call last):
  File "C:/Python27/Lib/site-packages/pygame/examples/test.py", line 25, in <module>
    input(pygame.event.get())
  File "C:/Python27/Lib/site-packages/pygame/examples/test.py", line 20, in input
    sys.exit(0)
SystemExit: 0

... And then the program doesn't exit. What am I doing wrong here? Because I did notice that this code was for an antiquated version of Python.

Answer 1

sys.exit() 

alone is a bit unholy with pygame.. the proper way to exit a pygame app is to first break out of the mainloop then quit pygame then quit the program. ie.

while running == True:
    # catch events
    if event_type == quit:
        running = False  # breaks out of the loop

pygame.quit()  # quits pygame
sys.exit()

also it seems to me that you aren't catching the event properly.. it should be

if event.type == pygame.QUIT:

you can read more about events in pygame here.

Answer 2

sys.exit just throws an exception (a SystemExit exception). This has two unusual effects:

1. It only exits the current thread in a multithreaded application
2. The exception could have been caught.

Answer 3

I solved this problem and the right code is below:

running = True
while running == True:
    for event in pygame.event.get():
        if event.type == QUIT:
            running = False  # Exiting the while loop

    screen.blit(background, (0,0))
    pygame.display.update()

pygame.quit() # Call the quit() method outside the while loop to end the application.