python - 迭代列表的字典时出现 IndexError : string index out of range,

Question

如果这应该被认为是重复的，我很抱歉，我检查了其他几个问题，但找不到错误，因为它可能对我的情况来说很特殊......

我知道问题出在这里，我用它来绘制字典中的每个字符:

编辑:好吧，这是为了抽象一个具体的例子，我不知道哪里出了问题，所以我将发布整个代码:

import pygame, random, time, sys, string, itertools

check_errors = pygame.init()

################### Main Variables ######################

PSwith = 460
PSheight = 460
playSurface = pygame.display.set_mode((PSwith, PSheight))

rowsCount = int(PSwith/10 - 1)
columnsCount = int(PSheight/10 - 1)

print('rows: ', rowsCount)
print('columns: ', columnsCount)

alphabet = list(string.ascii_letters + string.punctuation + string.digits)

red = pygame.Color(255,0,0)
blue = pygame.Color(0,0,255)
green = pygame.Color(0,255,0)
white = pygame.Color(255,255,255)
black = pygame.Color(0,0,0)

defaultColor = green
activeColor = white

fpsController = pygame.time.Clock()

################### Important Functions ######################

def drawChar(char, x, y, color):
    CharFont = pygame.font.SysFont('hermit', 15)
    CharSurf = CharFont.render(char, True, color)
    CharRect = CharSurf.get_rect()
    CharRect.midtop = (x, y)
    playSurface.blit(CharSurf, CharRect)

CharPosMatrix = []
CharLibrary = []

def setCharPos(row):
    for column in range(1, int(PSwith/10)):
        CharPosMatrix.append((column*10, row*10))

for row in range(1, int(PSheight/10)):
    setCharPos(row)

print('CharPosMatrix: ', CharPosMatrix)
print('len CharPosMatrix:', len(CharPosMatrix))


### assembling char library, with default color ###
for i in range(rowsCount * columnsCount):
        CharLibrary.append([random.choice(alphabet), defaultColor])

print('CharLibrary: ', CharLibrary)
print('len CharLibrary:', len(CharLibrary))

#MatrixDict = dict(zip(CharLibrary, CharPosMatrix))
MatrixDict = dict(zip(CharPosMatrix,CharLibrary)) #zipping each character with a x,y coord
print('MatrixDict: ', MatrixDict)
print('len MatrixDict: ', len(MatrixDict))

################### Main Loop ######################

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

    playSurface.fill(black)

    holderlist = []
    indexCounter = 0


    for key, value in MatrixDict.items():
        drawChar(value[0], key[0], key[1], value[1])
        print(key)
        print(value)

    ### start changing random elements ###

    n = 0
    for i in range(random.randint(1, 200)):
        MatrixDict[random.choice(CharPosMatrix)]= random.choice(alphabet)
        n += 1
    print('randomly changed characters: ', n)

    randColumn = 0
    for i in range(10):
        MatrixDict[(10, 10)] = 'X'

    pygame.display.flip()

    fpsController.tick(60) 

我实际上知道错误产生的部分是:

        for key, value in MatrixDict.items():
            drawChar(value[0], key[0], key[1], value[1])
            print(key)
            print(value) 

如果我将 value[1] 更改为变量 green，即代码运行...

Answer 1

您一开始就正确设置了 MatrixDict，并且第一次迭代主 while 循环时一切正常。然而，在 while 循环的末尾有两行可以修改 MatrixDict，这会破坏 future 迭代的代码:

88: MatrixDict[random.choice(CharPosMatrix)] = random.choice(alphabet)
94: MatrixDict[(10, 10)] = 'X'

在这两种情况下，您都需要指定颜色和字符，例如:

88: MatrixDict[random.choice(CharPosMatrix)] = random.choice(alphabet), defaultColor
94: MatrixDict[(10, 10)] = 'X', defaultColor