(IndexError: list index out of range) 我的 for 循环给了我一个错误？

Question

这是我的代码：

import game, pygame, sys
from gameobjects import *
from imageloader import *




def main():
    screen = pygame.display.set_mode( (800, 600) )
    background = Background("images/Nebula1.bmp", screen.get_width(), screen.get_height())
    letter1 = pygame.image.load("1.bmp")
    letter2 = pygame.image.load("2.bmp")
    letter3 = pygame.image.load("3.bmp")
    letter4 = pygame.image.load("4.bmp")
    letter5 = pygame.image.load("5.bmp")
    letter6 = pygame.image.load("6.bmp")
    letter7 = pygame.image.load("7.bmp")
    letter8 = pygame.image.load("8.bmp")
    letter9 = pygame.image.load("9.bmp")
    letter10 = pygame.image.load("10.bmp")
    Letters = [letter1, letter2, letter3, letter4, letter5, letter6, letter7, letter8, letter9, letter10]
    letter = 0

    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                sys.exit()

        screen.blit(background.image, (0,0))

        for i in Letters:
            screen.blit( Letters[letter], (330 + 14 * letter, 190) )
            letter += 1


        pygame.display.flip()
All the items in the Letters list are pygame.Surfaces retrieved through using pygame.image.load(). Every time I run this code, I get an error that looks like this:

    Traceback (most recent call last):
      File "main.py", line 75, in <module>
        main()
      File "main.py", line 32, in main
        screen.blit( Letters[letter], ((330 + 14 * letter, 190)) )
    IndexError: list index out of range

为什么会这样？这对我来说似乎完全有效。我究竟做错了什么？我想要做的是将屏幕上的每个字母粘贴到上一个 14 像素的位置，因为每个字母都是 14 像素宽。有什么帮助吗？ （我是python新手，所以如果我犯了一个愚蠢的错误，请原谅我。）

Answer 1

您必须为每次迭代设置letter = 0。因为它在 while 循环之外，所以 letter 仅在初始化时设置为 0。之后它在for i in letters 的第二次迭代中抛出IndexError，因为letter 现在等于letters 的长度，因为最后一次迭代！

使用enumerate() 确保安全并轻松增加：

for i,val in enumerate(Letters):
        screen.blit( Letters[i], (330 + 14 * letter, 190) )

或者，在 while 循环中包含 letter = 0：

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

    screen.blit(background.image, (0,0))

    letter = 0
    for i in Letters:
        screen.blit( Letters[i], (330 + 14 * letter, 190) )
        letter += 1