Python PyTmx播放器运动

我遵循了本教程：

我遇到了这个问题

玩家不移动，地图移动

我不知道这个问题是从哪里来的

代码如下：

import pygame
import sys
import os

import pytmx
from pytmx.util_pygame import load_pygame

os.environ["SDL_VIDEO_CENTERED"] = "1"
pygame.init()
SCREENWIDTH = 1000
SCREENHEIGHT = 900
SCREENSIZE = [SCREENWIDTH, SCREENHEIGHT]
SCREEN = pygame.display.set_mode(SCREENSIZE)

tiled_map = load_pygame('Test2.tmx')
tilewidth = tiled_map.tilewidth
tileheight = tiled_map.tileheight

CAMERA = tiled_map.get_object_by_name("Player")

pygame.display.set_caption("My first game in pygame")
collision = tiled_map.get_layer_by_name('PlatForm')
player = pygame.image.load("p1_front.png").convert_alpha();

while True:
    for events in pygame.event.get():
        if events.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
    for layer in tiled_map.layers:
        if isinstance(layer, pytmx.TiledTileLayer):
            for x, y, tile in layer.tiles():
                if (tile):
                    SCREEN.blit(tile, [(x*tilewidth) - CAMERA.x +(SCREENWIDTH/2) , (y*tileheight) - CAMERA.y + (SCREENHEIGHT/2)])

        if isinstance(layer, pytmx.TiledObjectGroup):
            for object in layer:
                if (object.name == 'Player'):
                    SCREEN.blit(player, [object.x - CAMERA.x +(SCREENWIDTH/2), object.y - CAMERA.y + (SCREENHEIGHT/2)])

        pygame.display.update()
    pos = [0, 0]
    PRESSED = pygame.key.get_pressed()

    if PRESSED[pygame.K_LEFT]:
        pos[0] -= 10
    elif PRESSED[pygame.K_RIGHT]:
        pos[0] += 10
    if PRESSED[pygame.K_UP]:
        pos[1] -= 10
    elif PRESSED[pygame.K_DOWN]:
        pos[1] += 10

    tiled_map.get_object_by_name("Player").x += pos[0]
    tiled_map.get_object_by_name("Player").y += pos[1]

提前感谢您的帮助