Pygame error: mixer system not initialized

Question

I've just started a little game project and I'm trying to make it play a sound everytime a bullet is fired but i keep getting the same error:

pygame.error: mixer system not initialized

I don't get what I've done wrong, so here is my code:

import pygame, sys
from pygame.locals import *

theClock = pygame.time.Clock()

sound = pygame.mixer.Sound("bullet.mp3")

....

if event.type == KEYDOWN:
    if event.key == K_SPACE and shot_count == 0:
        sound.play()
        shot_y = h-50
        shot_x = x
    elif event.type == K_SPACE and shot_count == 1:
        shot_y_2 = h-50
        shot_x_2 = x
    print(h, ' ', shot_y, shot_count)
if event.type == KEYUP:
    if event.key == K_SPACE and shot_count == 0:
        resetShot = 0 
    elif event.type == K_SPACE and shot_count == 1:
        resetShot = 0

Answer 1

I was looking here and found out that pygame only loads OGG ang uncompressed WAV files. Another issue is you forgot to initialize the pygame.mixer module.

pygame.mixer.init()

is the most simple way to initialize the pygame.mixer module. For more info, go to the previous link.

Answer 2

You need to pygame.init() before using mixer/sound objects.

According to documentation, you should use OGG or WAV sound files.