Getting an error message in pygame - python-3.x

Question

import pygame
import random
from os import path
img_dir = path.join(path.dirname(__file__), 'img')
snd_dir = path.join(path.dirname(__file__), 'sound')
WIDTH = 800
HEIGHT = 600
FPS = 50
WHITE=(255, 255, 255)
BLACK=(0, 0, 0)
RED=(255, 0, 0)
GREEN=(0, 255, 0)
BLUE=(0, 0, 255)
YELLOW=(255, 255, 0)
pygame.init()
pygame.mixer.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("My Game")
clock = pygame.time.Clock()
font_name = pygame.font.match_font('arial')
end = True
def start_screen():
draw_text(screen, "SPACE SHOOTING", 70, WIDTH/2, HEIGHT/4)
draw_text(screen, "INSTRUCTIONS", 25, WIDTH/2, HEIGHT/2)
draw_text(screen, "Press Left arrow key to move left", 20, WIDTH/2, HEIGHT*2/3.5)
draw_text(screen, "Press Right arrow key to move right", 20, WIDTH/2, HEIGHT*2/3.3)
draw_text(screen, "Spacebar to shoot", 20, WIDTH/2, HEIGHT*2/3.1)
draw_text(screen, "Press a key to begin", 20, WIDTH/2, HEIGHT*3/4)
pygame.display.flip()
wait = True
while wait:
clock.tick(FPS)
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
if event.type == pygame.KEYUP:
if event.key == pygame.K_SPACE:
wait = False
def draw_text(surf, text, size, x, y):
font = pygame.font.Font(font_name, size)
text_surface = font.render(text, True, WHITE)
text_rect = text_surface.get_rect()
text_rect.midtop = (x, y)
surf.blit(text_surface, text_rect)
class Player(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.transform.scale(player_img, (50, 38))
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
self.radius = 20
self.rect.centerx = WIDTH/2
self.rect.bottom = HEIGHT - 10
self.speedx = 0
def update(self):
self.speedx = 0
keystate = pygame.key.get_pressed()
if keystate[pygame.K_LEFT]:
self.speedx = -5
if keystate[pygame.K_RIGHT]:
self.speedx = 5
self.rect.x += self.speedx
if self.rect.right > WIDTH:
self.rect.right = WIDTH
if self.rect.left < 0:
self.rect.left = 0
def shoot(self):
bullet = Bullets(self.rect.centerx, self.rect.top)
all_sprites.add(bullet)
bullets.add(bullet)
class Aliens(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = aliens_img
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
self.radius = int(self.rect.width*.85/2)
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(-100, -40)
self.speedy = random.randrange(1, 8)
def update(self):
self.rect.y += self.speedy
if self.rect.top > HEIGHT + 10 or self.rect.left < -25 or self.rect.right > WIDTH + 20:
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(-100, -40)
self.speedy = random.randrange(1, 8)
class SuperAliens(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = superaliens_img
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
self.radius = int(self.rect.width*.85/2)
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(-100, -40)
self.speedy = random.randrange(1, 8)
self.speedx = random.randrange(-3, 3)
def update(self):
self.rect.x += self.speedx
self.rect.y += self.speedy
if self.rect.top > HEIGHT + 10 or self.rect.left < -25 or self.rect.right > WIDTH + 20:
self.rect.x = random.randrange(WIDTH - self.rect.width)
self.rect.y = random.randrange(-100, -40)
self.speedy = random.randrange(1, 8)
def shoot1(self):
sbullet = SBullets(self.rect.centerx, self.rect.bottom)
all_sprites.add(sbullet)
bullets.add(sbullet)
class SBullets(pygame.sprite.Sprite):
def __init__(self, x, y):
pygame.sprite.Sprite.__init__(self)
self.image = sbullet_img
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
self.rect.bottom = y
self.rect.centerx = x
self.speedy = +10
def update(self):
self.rect.y += self.speedy
if self.rect.top < 0:
self.kill()
class Bullets(pygame.sprite.Sprite):
def __init__(self, x, y):
pygame.sprite.Sprite.__init__(self)
self.image = bullet_img
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
self.rect.bottom = y
self.rect.centerx = x
self.speedy = -10
def update(self):
self.rect.y += self.speedy
if self.rect.bottom < 0:
self.kill()
class Explode(pygame.sprite.Sprite):
def __init__(self, center, size):
pygame.sprite.Sprite.__init__(self)
self.size = size
self.image = explode[self.size][0]
self.rect = self.image.get_rect()
self.rect.center = center
self.frame = 0
self.last_update = pygame.time.get_ticks()
self.frame_rate = 2
def update(self):
now = pygame.time.get_ticks()
if now - self.last_update > self.frame_rate:
self.last_update = now
self.frame += 1
if self.frame == len(explode[self.size]):
self.kill()
else:
center = self.rect.center
self.image = explode[self.size][self.frame]
self.rect = self.image.get_rect()
self.rect.center = center
background = pygame.image.load(path.join(img_dir, "back.png")).convert()
background_rect = background.get_rect()
player_img = pygame.image.load(path.join(img_dir, "playerShip2_blue.png")).convert()
superaliens_img = pygame.image.load(path.join(img_dir, "enemyBlack4.png")).convert()
aliens_img = pygame.image.load(path.join(img_dir, "enemyBlack1.png")).convert()
bullet_img = pygame.image.load(path.join(img_dir, "laserRed16.png")).convert()
sbullet_img = pygame.image.load(path.join(img_dir, "laserRed11.png")).convert()
explode = {}
explode['super']=[]
explode['small']=[]
for i in range(9):
filename = 'regularExplosion02.png'.format(1)
img = pygame.image.load(path.join(img_dir, filename)).convert()
img.set_colorkey(BLACK)
img_super = pygame.transform.scale(img, (75, 75))
explode ['super'].append(img_super)
img_small = pygame.transform.scale(img, (32, 32))
explode ['small'].append(img_small)
#pygame.mixer.music.load(path.join(snd_dir, 'Orbital.mp3'))
#pygame.mixer.music.set_volume(0.4)
#pygame.mixer.music.play(loops=-1)
end_game = True
running = True
while running:
if end_game:
start_screen()
end_game = False
all_sprites = pygame.sprite.Group()
aliens = pygame.sprite.Group()
superaliens = pygame.sprite.Group()
bullets = pygame.sprite.Group()
sbullets = pygame.sprite.Group()
player = Player()
all_sprites.add(player)
for i in range(5):
m = Aliens()
all_sprites.add(m)
aliens.add(m)
for j in range(1):
n = SuperAliens()
all_sprites.add(n)
superaliens.add(n)
score = 0
clock.tick(FPS)
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
player.shoot()
all_sprites.update()
hits = pygame.sprite.groupcollide(aliens, bullets, True, True)
for hit in hits:
score += 1
m = Aliens()
expl = Explode(hit.rect.center, 'small')
all_sprites.add(expl)
all_sprites.add(m)
aliens.add(m)
hits = pygame.sprite.groupcollide(superaliens, bullets, True, True)
for hitt in hits:
score += 5
n = SuperAliens()
expl1 = Explode(hitt.rect.center, 'super')
all_sprites.add(expl1)
all_sprites.add(n)
superaliens.add(n)
hits = pygame.sprite.spritecollide(player, aliens, True)
for hit in hits:
expl = Explode(hit.rect.center, 'small')
all_sprites.add(expl)
if hits:
end_game = True
hits = pygame.sprite.spritecollide(player, superaliens, True)
for hitt in hits:
expl1 = Explode(hitt.rect.center, 'super')
all_sprites.add(expl1)
if hits:
end_game = True
screen.fill(BLACK)
screen.blit(background, background_rect)
all_sprites.draw(screen)
draw_text(screen,"SCORE" +str(score), 22, WIDTH/2, 10)
#after drwing everything flip the display
pygame.display.flip()
pygame.quit()
Sorry for the bad formatting but couldn't upload it with the proper formatting. Its my first pygame, so im not good in it. The program is working good, but every time when i close the window, its is showing me this error.
Traceback (most recent call last):
File "/Users/Documents/game.py", line 221, in
start_screen()
File "/Users/Documents/game.py", line 41, in start_screen
for event in pygame.event.get():
pygame.error: video system not initialized
I was also trying to make the super aliens shoot randomly towards the player, and that thing is not working as well.A little help would be appreciated. Thanks

Answer 1

After the line:
pygame.quit()
put:
exit()
Basically, pygame.quit() tells pygame that you are done with it. After you call it in your event loop, pygame no longer can draw things to the screen, but you still try to make it do so later in your program. Calling exit() makes python exit so that pygame is not told to draw anything.