So I've been working side by side with the pygame tutorial (most of the times running ahead and confirming with a video)
Everything works fine up 'till now , BUT.

I'm at the shell explosion phase the code is :

def explosion(x, y):

    explode = True

    while explode:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:

        startPoint = x, y

        colorChoices = [red, bright_red, yellow, bright_yellow]

        magnitude = 1

        while magnitude < 50:
            exploding_bit_x = x + random.randrange(-1*magnitude, magnitude)
            exploding_bit_y = y + random.randrange(-1*magnitude, magnitude)
            pygame.draw.circle(gameDisplay, colorChoices[random.randrange(0, 4)], (exploding_bit_x, exploding_bit_y), random.randrange(1, 5))

            magnitude = magnitude + 1

        explode = False            

Now, when I'm running the code and playing the game, right after I fire the shot and it hits y = 0, the shell explodes, keeps exploding and goes on to no end, how can I fix this?