Pygame Shooting Bullets With Mouse

import pygame
from pygame.sprite import Sprite, Group
from types import SimpleNamespace

color = SimpleNamespace(**pygame.color.THECOLORS)

class Scene:
    def __init__(self, manager):
        self.manager = manager

    def on_draw(self, surface): pass
    def on_event(self, event): pass
    def on_update(self, delta): pass

class Manager:
    def __init__(self, caption, width, height, flags=0):
        # Basic pygame setup
        pygame.display.set_caption(caption)
        self.surface = pygame.display.set_mode((width, height), flags)
        self.rect = self.surface.get_rect()
        self.clock = pygame.time.Clock()
        self.running = False
        self.delta = 0
        self.fps = 60

        self.scene = Scene(self)

    def mainloop(self):
        self.running = True
        while self.running:
            for event in pygame.event.get():
                if event.type == pygame.QUIT:
                    self.running = False
                else:
                    self.scene.on_event(event)

            self.scene.on_update(self.delta)
            self.scene.on_draw(self.surface)
            pygame.display.flip()
            self.delta = self.clock.tick(self.fps)

class Bullet(Sprite):
    def __init__(self, image, position, direction, speed, distance):
        Sprite.__init__(self)
        self.image = image
        self.speed = speed * 0.001
        self.distance = distance
        self.direction = direction
        self.rect = image.get_rect(topleft=position)
        self.position = pygame.Vector2(self.rect.topleft)
        self.start_position = pygame.Vector2(self.rect.topleft)

    def update(self, delta):
        self.position += self.direction * self.speed * delta
        self.rect.topleft = self.position
        if self.position.distance_to(self.start_position) > self.distance:
            self.kill()

class MySprite(Sprite):
    def __init__(self, image, position, anchor="topleft"):
        Sprite.__init__(self)
        self.image = image
        self.rect = image.get_rect(**{anchor: position})

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

class Movement:
    def __init__(self, sprite, speed,
                 up = (pygame.K_UP, pygame.K_w),
                 down = (pygame.K_DOWN, pygame.K_s),
                 left = (pygame.K_LEFT, pygame.K_a),
                 right = (pygame.K_RIGHT, pygame.K_d)):

        self.sprite = sprite
        self.speed = speed * 0.001
        self.position = pygame.Vector2(sprite.rect.center)

        self.up = up
        self.down = down
        self.left = left
        self.right = right

    def move(self, delta, keys):
        direction = pygame.Vector2(0, 0)
        if any([keys[k] for k in self.up]):
            direction.y = -1
        elif any([keys[k] for k in self.down]):
            direction.y = 1

        if any([keys[k] for k in self.left]):
            direction.x = -1
        elif any([keys[k] for k in self.right]):
            direction.x = 1

        if direction != pygame.Vector2(0, 0):
            direction.normalize_ip()
            self.position += direction * self.speed * delta
            self.sprite.rect.center = self.position

class Player:
    def __init__(self, position, anchor="topleft"):
        image = pygame.Surface((20, 20))
        image.fill(color.firebrick)

        self.bullet_image = pygame.Surface((2, 2))
        self.bullet_image.fill(color.gray30)

        self.sprite = MySprite(image, position, anchor)
        self.movement = Movement(self.sprite, 50)
        self.bullets = Group()

    def draw(self, surface):
        self.sprite.draw(surface)
        self.bullets.draw(surface)

    def shoot_bullet(self, event):
        direction = (pygame.Vector2(event.pos) - self.movement.position).normalize()
        self.bullets.add(Bullet(self.bullet_image, self.movement.position, direction, 200, 300))

    def update(self, delta, keys):
        self.bullets.update(delta)
        self.movement.move(delta, keys)

class GameScene(Scene):
    def __init__(self, manager):
        Scene.__init__(self, manager)
        self.player = Player(manager.rect.center, "center")

    def on_draw(self, surface):
        surface.fill(color.black)
        self.player.draw(surface)

    def on_event(self, event):
        if event.type == pygame.MOUSEBUTTONDOWN:
            if event.button == 1:
                self.player.shoot_bullet(event)

    def on_update(self, delta):
        keys = pygame.key.get_pressed()
        self.player.update(delta, keys)

if __name__ == "__main__":
    pygame.init()
    manager = Manager("Bullet Shooting Example", 800, 600)
    manager.scene = GameScene(manager)
    manager.mainloop()