Python的list对象不允许索引值更改

Question

我正在用Python和Pygame创建我的第一个游戏。它由落在地上的物体和由玩家控制的物体组成。 然而，当坠落物体撞击地面时，它给了我一个例外：

Traceback (most recent call last):
  File "/home/me/Chest/game.py", line 79, in <module>
    resetShirtPosition()
  File "/home/me/Chest/game.py", line 35, in resetShirtPosition
    shirtPosition[0] = random.randint(0, DISPLAY_WIDTH - shirt_size[0])
TypeError: 'tuple' object does not support item assignment

似乎不允许向量按索引改变。我觉得很奇怪，因为我不是用元组来赋值shirtPosition，而是用list。除此之外，我正在以相同的方式更改chestPosition，它移动时不会崩溃。你知道吗

这是我的密码：

import pygame, random, os

pygame.init()

DISPLAY_WIDTH, DISPLAY_HEIGHT = 1600, 900

clock   = pygame.time.Clock()
gamedisplay = pygame.display.set_mode((DISPLAY_WIDTH, DISPLAY_HEIGHT))

chest_imag  = pygame.image.load(os.path.join("catcher.png"))
shirt_red   = pygame.image.load(os.path.join("shirt_red.png"))
background  = pygame.image.load(os.path.join("background.png"))
shirt_blue  = pygame.image.load(os.path.join("shirt_blue.png"))
shirt_green = pygame.image.load(os.path.join("shirt_green.png"))

shirt = shirt_blue

chest_size = chest_imag.get_size()
chestPosition = [DISPLAY_WIDTH / 2, DISPLAY_HEIGHT - chest_size[1]]

shirt_blue_size = shirt_blue.get_size()
shirt_size      = shirt_blue_size

shirtPosition = [random.randint(0, DISPLAY_WIDTH - shirt_size[0]), 0]

dX, dY = 0, 20
score = 0
fallWidth = fallHeight = 100
COLLISION_LEVEL_LINE = DISPLAY_HEIGHT - chest_size[1]

onGame = True
collide = False

# **************** Exception happens here *******************
def resetShirtPosition():
    shirtPosition[0] = random.randint(0, DISPLAY_WIDTH - shirt_size[0])
    shirtPosition[1] = 0

def hitCollisionLevelLine():
    return (shirtPosition[1] + shirt_size[1]) >= COLLISION_LEVEL_LINE

def hitGround():
    return (shirtPosition[1] + shirt_size[1]) >= DISPLAY_HEIGHT

def hitHorizontalEdge():
    willTouchLeftEdge = (chest_size[0] + dX) < 0
    willTouchRightEdge = (chest_size[0] + dX) > (DISPLAY_WIDTH  - chest_size[0])
    return willTouchLeftEdge or  willTouchRightEdge

def collides():
    touchFromLeft = shirtPosition[0] > (chestPosition[0] - shirt_size[0])
    touchFromRight = shirtPosition[0] < (chestPosition[0] + chest_size[0])
    return touchFromLeft and touchFromRight

while onGame:
    clock.tick(60)

    # action
    for event in pygame.event.get():
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_a:
                dX = -20
            elif event.key == pygame.K_d:
                dX = 20
        elif event.type == pygame.KEYUP:
            dX = 0
        elif event.type == pygame.QUIT:
            onGame = false

    # logic
    if hitCollisionLevelLine():
        hasCollided = collides()
        if hasCollided:
            collide = False
            score = score + 1
            print score
            resetShirtPosition()

    if hitGround():
        resetShirtPosition()

    if hitHorizontalEdge():
        dX = 0

    # update positions and draw
    chestPosition = (chestPosition[0] + dX, chestPosition[1])
    shirtPosition = (shirtPosition[0], shirtPosition[1] + dY)

    gamedisplay.blit(background , (0, 0))
    gamedisplay.blit(shirt_blue, shirtPosition)
    gamedisplay.blit(chest_imag, chestPosition)

    pygame.display.flip()

我已经发布了我所有的代码，因为我也希望你能给我一些提示来改进它，从代码编写到提高性能技巧。例如，我想把我的图片放到字典里，然后按它的键（名称）来获取它们。非常感谢。你知道吗

Answer 1

在以下行：

shirtPosition = (shirtPosition[0], shirtPosition[1] + dY)

您已将shirtPosition重新分配为元组，这导致了您的问题。 请将其转换为列表对象，您的问题将得到解决。你知道吗