我正在创建一个带有菜单的蛇Pygame，并在调试错误时进行了微调
IndexError：列表索引超出范围
打开标签本身并将光标移到它上之后，错误实际上就会出现
我对它的真正含义不甚了解，但对于python和编码我还是很陌生，所以如果有人可以解释并给出解决方案，我将不胜感激，
非常感谢，这里是代码
import pygame
import sys
import random
import time
pygame.init()
WHITE = (255, 255, 255)
YELLOW = (255, 255, 102)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
DARKRED = (125, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
screenWidth = 800
screenHeight = 800
screen = pygame.display.set_mode((screenWidth, screenHeight))
pygame.display.set_caption('Snake Game')
clock = pygame.time.Clock()
snakeBlock = 10
snakeSpeed = 15
fontTitle = pygame.font.SysFont("arial",100)
fontStyle = pygame.font.SysFont("ariel", 50)
scoreFont = pygame.font.SysFont("ariel", 35)
def score(score):
value = scoreFont.render(" Score: " + str(score), True, BLACK)
screen.blit(value, [50, 50])
def snake(snakeBlock, snake_list):
for x in snake_list:
pygame.draw.rect(screen, GREEN, [x[0], x[1], snakeBlock, snakeBlock])
def message(msg, colour):
msg = fontStyle.render(msg, True, BLACK)
screen.blit(msg, [screenWidth / 20, screenHeight / 2])
def gameLoop():
gameOver = False
gameEnd = False
instructions = False
game = True
intro = True
main = True
x1 = screenWidth / 2
y1 = screenHeight / 2
dx = 0
dy = 0
snakeList = []
snakeLength = 2
foodx = round(random.randrange(0, screenWidth - snakeBlock) / 10.0) * 10.0
foody = round(random.randrange(0, screenHeight - snakeBlock) / 10.0) * 10.0
def menu(titles):
buttonTitleFont = pygame.font.SysFont("arial", 52)
selection = []
rectWidth = 400
rectHeight = 60
x = int(screen.get_width()/2 - rectWidth/2)
y = 450
length = len(titles)
num = 0
hover = False
# creates the Rects (containers) for the buttons
for i in range (0,length,1):
choiceRect = pygame.Rect(x,y,rectWidth,rectHeight)
selection.append(choiceRect)
y += 100
#main loop in menu
menu = True
while menu:
for event in pygame.event.get():
if event.type == pygame.QUIT:
menu = False
pygame.quit()
sys.exit()
if event.type ==pygame.MOUSEMOTION: # if mouse moved
hover = False
mx, my = pygame.mouse.get_pos() # get the mouse position
for i in range (length):
if selection[i].collidepoint((mx,my)): # check if x,y of mouse is in a button
num = i
hover = True
if event.type == pygame.MOUSEBUTTONDOWN and hover == True: #if mouse is in button
menu = False # and has been clicked
# draw all buttons
for choice in selection:
pygame.draw.rect(screen,WHITE,choice,0)
# redraw selected button in another colour
pygame.draw.rect(screen,GREEN,selection[num],0)
# draw all the titles on the buttons
x = int(screen.get_width()/2 - 150)
y = 450
for i in range(0,length,1):
buttonTitle = buttonTitleFont.render(titles[i],True,BLACK)
screen.blit(buttonTitle,(x,y))
y += 100
pygame.display.update()
return num
while main:
for event in pygame.event.get(): # check for any events (i.e key press, mouse click etc.)
if event.type ==pygame.QUIT: # check to see if it was "x" at top right of screen
main = False # set the "main" variable to False to exit while loop
while intro:
for event in pygame.event.get():
if event.type == pygame.QUIT:
main = False
intro = False
screen.fill(BLACK)
menuMain = ["Launch", "Instructions","QUIT"]
mainMenu = True
mainInt = True
while mainInt:
for event in pygame.event.get():
if event.type == pygame.QUIT:
main = False
intro = False
mainInt = False
screen.fill(BLACK)
#Centers the rendered tiles
textTitle = fontTitle.render("Snake", True, GREEN )
textW = textTitle.get_width()
textH = textTitle.get_height()
xTitle = int(screenWidth/2 - textW/2)
yTitle = int(screenHeight/4 - textH/2)
screen.blit(textTitle, (xTitle,yTitle))
pygame.display.update()
# in the intro, this asks the user where they would like to go
if mainMenu ==True:
choose = menu(menuMain)
if choose == 0:
menu = False
intro = False
mainInt = False
mainMenu = False
game = True
screen.fill(BLACK)
elif choose ==1:
menu = False
instructions = True
mainMenu = False
screen.fill(BLACK)
pygame.display.update()
else:
menu = False
main = False
intro = False
mainInt = False
mainMenu = False
while game:
if gameOver == True:
game = False
while gameEnd == True:
screen.fill(DARKRED)
message("You Lost! Press C to Play Again or Q to Quit", RED)
score(snakeLength - 1)
pygame.display.update()
for event in pygame.event.get():
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_q:
gameOver = True
gameEnd = False
if event.key == pygame.K_c:
gameLoop()
for event in pygame.event.get():
if event.type == pygame.QUIT:
gameOver = True
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_LEFT:
dx = -snakeBlock
dy = 0
elif event.key == pygame.K_RIGHT:
dx = snakeBlock
dy = 0
elif event.key == pygame.K_UP:
dx = 0
dy = -snakeBlock
elif event.key == pygame.K_DOWN:
dx = 0
dy = snakeBlock
if x1 >= screenWidth or x1 < 0 or y1 >= screenHeight or y1 < 0:
gameEnd = True
x1 += dx
y1 += dy
screen.fill(WHITE)
pygame.draw.rect(screen, RED, [foodx, foody, snakeBlock, snakeBlock])
snakeHead = []
snakeHead.append(x1)
snakeHead.append(y1)
snakeList.append(snakeHead)
if len(snakeList) > snakeLength:
del snakeList[0]
for x in snakeList[:-1]:
if x == snakeHead:
gameEnd = True
snake(snakeBlock, snakeList)
score(snakeLength - 1)
pygame.display.update()
if x1 == foodx and y1 == foody:
foodx = round(random.randrange(0, screenWidth - snakeBlock) / 10.0) * 10.0
foody = round(random.randrange(0, screenHeight - snakeBlock) / 10.0) * 10.0
snakeLength += 1
clock.tick(snakeSpeed)
pygame.quit()
quit()
gameLoop()
答案 0 :(得分：3)
我看到在您的代码中，您多次引用selection[some_index]。如果查看实际选择的内容，您会发现它是一个数组，其中包含一个矩形对象：
[<rect(200, 450, 400, 60)>]
此矩形永远不会更改，因此我建议通过调用
直接引用它 selection[0]
例如，这是给您错误的代码段。
for i in range (length):
if selection[i].collidepoint((mx,my)): # check if x,y of mouse is in a button
num = i
hover = True
由于选择是一个数组，该数组具有一个永不更改的元素，因此在for循环的第一次迭代后会出现索引超出范围错误。也许这看起来很熟悉：
IndexError: list index out of range
解决此问题的方法是摆脱循环（因为这是不必要的-如果选择列表中只有一个矩形，则不应遍历索引！）并在第0个索引处提取矩形
if selection[0].collidepoint((mx,my)): # check if x,y of mouse is in a button
num = i
hover = True
这不是我在您的代码中遇到的唯一错误，但是我相信这会对您有所帮助！