Unable to exit Pygame window

[Hesper]

Hello friends I am new to pygame and python. The thing is I am not able to exit the python program even after I click the exit button on the pygame window. Here is my code:

import pygame
import sys

pygame.init()

WIDTH = 800
HEIGHT = 600

screen = pygame.display.set_mode((WIDTH, HEIGHT))

gameOver = False

while not gameOver:
	for event in pygame.event.get():
		if event.type == pygame.QUIT:
			sys.exit()

And instead I get this as output:

Output:
Traceback (most recent call last):
  File "/home/my-dell/dev/Documents/Programming projects/Practical_Python/atbsp.py", line 16, in <module>
    sys.exit()
SystemExit

Thanks in advance. I am using Ubuntu 16.04 LTS.