PyGame - moving player and shooting bullets

#
# https://www.reddit.com/r/learnpython/comments/4uy0rn/new_to_python_having_problems_with_pygame_and/
#

import pygame

# --- constants - Uppercase ---

# Colors used in the game
BLACK   = (   0,   0,   0)
WHITE   = ( 255, 255, 255)
GREEN   = (   0, 255,   0)
RED     = ( 255,   0,   0)

# Size of the window / open window
SIZE = (700, 500)

# --- classes --- CamelCase ---

class Bullet(pygame.sprite.Sprite):

    def __init__(self, position):
        super().__init__()

        self.image = pygame.Surface([4,10])
        self.image.fill(WHITE)

        self.rect = self.image.get_rect()
        self.rect.center = position

    def update(self):
        self.rect.y -= 5


class Player(pygame.sprite.Sprite):

    def __init__(self):
        super().__init__()

        self.image = pygame.image.load("player1.png").convert()
        # Make color transparent
        self.image.set_colorkey(BLACK)

        self.rect = self.image.get_rect()

    def draw(self, screen):
        screen.blit(self.image, self.rect)

    def move(self, position):
        self.rect.center = position


# --- main ---

# Setup
pygame.init()

screen = pygame.display.set_mode(SIZE)
screen_rect = screen.get_rect() # to center background

# Window Title
pygame.display.set_caption("Andrew's Cool Game")

background_image = pygame.image.load("space1.jpg").convert()
background_image_rect = background_image.get_rect(center=screen_rect.center) # to center background

#click_sound = pygame.mixer.Sound("laser5.ogg")

# Hide mouse cursor
pygame.mouse.set_visible(False)

# Bullet List
bullet_list = pygame.sprite.Group()

# Player
player = Player()

# ---------------- MAIN PROGRAM LOOP ----------------

# Loop until user closes program
done = False

# Manages how fast screen updates
clock = pygame.time.Clock()

while done == False: # User did something

    # ----- PROCESSING -----

    for event in pygame.event.get(): # If user clicks close

        if event.type == pygame.QUIT:
            done = True

        # I like to use ESC to close example
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_ESCAPE:
                done = True

        # Moving player
        elif event.type == pygame.MOUSEMOTION:
            player.move(event.pos)

        # Play sound when mouse button is clicked
        elif event.type == pygame.MOUSEBUTTONDOWN:
            #click_sound.play()
            print ("Testing", event.pos)

            bullet = Bullet(event.pos)

            print(bullet.rect)
            bullet_list.add(bullet)

    # ----- PROCESSING END -----


    # ----- GAME LOGIC -----

    for bullet in bullet_list:

        if bullet.rect.y < -10:
            bullet_list.remove(bullet)

    bullet_list.update()

    # ----- GAME LOGIC END -----


    # ----- DRAW -----

    screen.blit(background_image, background_image_rect) # to center background

    player.draw(screen)

    bullet_list.draw(screen)

    # Update the screen with DRAW
    pygame.display.flip()

    # ----- DRAW END -----

    # Limit fps
    clock.tick(60)

# --- The End ---

pygame.quit()