Анимация спрайтов

import pygame as pg
 
TITLE = 'RETRO PALADIN!'
SIZE = WIDTH, HEIGHT = (1280, 720)
FPS = 120
ANIM_COUNT = 0
PAL_X_POS = 900
PAL_Y_POS = 485
 
pg.init()
screen = pg.display.set_mode(SIZE)
clock = pg.time.Clock()
pg.display.set_caption(TITLE)
 
 
background = pg.transform.scale(pg.image.load('assets/img/background.png').convert(), (WIDTH, HEIGHT))
 
'-----------------------------'
 
 
class Player(pg.sprite.Sprite):
    pal_anim_stay = []
    for i in range(4):
        filename = f'pal_{i}.png'
        img = pg.transform.scale(pg.image.load(f'assets/img/pal/stay/{filename}').convert_alpha(), (144, 144))
        pal_anim_stay.append(img)
    surf_stay = pal_anim_stay[ANIM_COUNT // 30]
 
    def __init__(self, group):
        pg.sprite.Sprite.__init__(self)
        self.image = Player.surf_stay
        self.rect = self.image.get_rect()
        self.add(group)
        self.rect.x = PAL_X_POS
        self.rect.y = PAL_Y_POS
        self.frame = ANIM_COUNT
        self.frame_rate = FPS
 
    def update(self):
        if self.frame + 1 >= self.frame_rate:
            self.frame = 0
        else:
            self.frame += 1
 
 
'-----------------------------'
 
sprites = pg.sprite.Group()
 
player = Player(sprites)
 
GAME_IS_DONE = False
 
while not GAME_IS_DONE:
    clock.tick(FPS)
    for event in pg.event.get():
        if event.type == pg.QUIT:
            GAME_IS_DONE = True
 
    screen.blit(background, (background.get_rect()))
    sprites.draw(screen)
    sprites.update()
 
    pg.display.update()
 
pg.quit()