python - 游戏代码中存在缩进问题

Question

import pygame, sys
from pygame.locals import *

CHARSPEED = 3

pygame.mixer.init()
pygame.mixer.music.load("nq-rotmg.mp3")
pygame.mixer.music.play(-1)

FPS = 30
fpsClock = pygame.time.Clock()

pywindow = pygame.display.set_mode((500, 500), 0, 32)
pygame.display.set_caption('God of the Mad Realm')

background = pygame.image.load("Background.jpg")
background = background.convert()
pywindow.blit(background, (0, 0))
pygame.display.flip()

Assassin = pygame.image.load("Assassin_L.png")

Assassin_R.set_colorkey((255, 255, 255))
Assassin_L.set_colorkey((255, 255, 255))
assassinx = 10
assassiny = 10
pygame.key.set_repeat(10, 10)

while True: 
    pywindow.blit(background, (0, 0))

    pywindow.blit(Assassin, (assassinx, assassiny))

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

    if event.type == KEYDOWN:
        if (event.key == K_LEFT):
            Assassin=pygame.image.load('Assassin_L.png')
        elif (event.key == K_RIGHT):  <<<-------------------------------------
            Assassin=pygame.image.load('Assassin_R.png')
        elif (event.key == K_UP):
            Assassin=pygame.image.load('Assassin_L.png')
        elif (event.key == K_DOWN):
            Assassin=pygame.image.load('Assassin_L.png')

keys_pressed = pygame.key.get_pressed()

if keys_pressed[K_LEFT]:
    assassinx -= CHARSPEED

elif keys_pressed[K_RIGHT]:
    assassinx += CHARSPEED

elif keys_pressed[K_UP]:
    assassiny -= CHARSPEED

elif keys_pressed[K_DOWN]:
    assassiny += CHARSPEED

pygame.display.update()
fpsClock.tick(FPS) 

就在我放置箭头的地方，我不断收到一条错误消息:

Traceback (most recent call last):
  File "Character.py", line 42, in <module>
    elif (event.key == K_RIGHT):
AttributeError: event member not defined

我确信这是一个愚蠢的错误，但它确实开始给我带来麻烦。

Answer 1

您的缩进还不正确。 AttributeError 的出现是由于 event 变量没有在正确的范围内定义。你的代码...

for event in pygame.event.get():# <<<--------
    if event.type==QUIT:
        pygame.quit()
        sys.exit()

if event.type == KEYDOWN:       # <<<--------
    if (event.key == K_LEFT):

if event.type == KEYDOWN 应嵌套在 for 循环下，以便 event 成为正确定义。因此，正确的代码应该是，

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

    if event.type == KEYDOWN:     #  one more indented
        if (event.key == K_LEFT): # corresponding appropriate indent
            Assassin=pygame.image.load('Assassin_L.png')
        elif (event.key == K_RIGHT):
            Assassin=pygame.image.load('Assassin_R.png')
        elif ...

此外，所有游戏执行代码都应位于 while True block 下。

while True:
    pywindow.blit(background, (0, 0))

    pywindow.blit(Assassin, (assassinx, assassiny))

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

    if event.type == KEYDOWN:
        if (event.key == K_LEFT):
            Assassin=pygame.image.load('Assassin_L.png')
        elif (event.key == K_RIGHT):
            Assassin=pygame.image.load('Assassin_R.png')
        elif (event.key == K_UP):
            Assassin=pygame.image.load('Assassin_L.png')
        elif (event.key == K_DOWN):
            Assassin=pygame.image.load('Assassin_L.png')

    keys_pressed = pygame.key.get_pressed()

    if keys_pressed[K_LEFT]:
        assassinx -= CHARSPEED

    elif keys_pressed[K_RIGHT]:
        assassinx += CHARSPEED

    elif keys_pressed[K_UP]:
        assassiny -= CHARSPEED

    elif keys_pressed[K_DOWN]:
        assassiny += CHARSPEED

    pygame.display.update()
    fpsClock.tick(FPS)