错误信息-(AttributeError: Worm实例没有属性'vx')是什么意思，我该如何修复？
我一直在跟着一个教程学习，但总是遇到以下错误
AttributeError: Worm instance has no attribute 'move'
我不太明白这是什么意思，也不知道该怎么解决。这个错误提到的是第44行，具体是w.move()(这个问题已经解决，见下文)
import pygame
class Worm:
"""A Worm."""
def __init__(self, surface, x, y, length):
self.surface = surface
self.x = x
self.y = y
self.length = length
self.dir_x = 0
self.dir_y = -1
self.body = []
self.crashed = False
def key_event(self, event):
"""Handle Key events that affect the worm."""
if event.key == pygame.K_UP:
self.dir_x = 0
self.dir_y = -1
elif event.key == pygame.K_DOWN:
self.dir_x = 0
self.dir_y = 1
elif event.key == pygame.K_DOWN:
self.dir_x = -1
self.dir_y = 0
elif event.key == pygame.K_DOWN:
self.dir_x = 1
self.dir_y = 0
def draw(self):
for x, y in self.body:
self.surface.set_at((x, y), (255, 255, 255))
width = 640
height = 400
screen = pygame.display.set_mode((width, height))
clock = pygame.time.Clock()
running = True
w = Worm(screen, width/2, height/2, 200)
while running:
screen.fill((0, 0, 0))
w.move()
w.draw()
if w.crashed or w.x <= 0 or w.x >= width -1 or w.y <= 0 or w.y >= height -1:
print "crash"
running = False
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
elif event.type == pygame.KEYDOWN:
w.key_event(event)
pygame.display.flip()
clock.tick(240)
----------更改 --------
代码：
import pygame
class Worm:
"""A Worm."""
def __init__(self, surface, x, y, length):
self.surface = surface
self.x = x
self.y = y
self.length = length
self.dir_x = 0
self.dir_y = -1
self.body = []
self.crashed = False
def key_event(self, event):
"""Handle Key events that affect the worm."""
if event.key == pygame.K_UP:
self.dir_x = 0
self.dir_y = -1
elif event.key == pygame.K_DOWN:
self.dir_x = 0
self.dir_y = 1
elif event.key == pygame.K_DOWN:
self.dir_x = -1
self.dir_y = 0
elif event.key == pygame.K_DOWN:
self.dir_x = 1
self.dir_y = 0
def draw(self):
for x, y in self.body:
self.surface.set_at((x, y), (255, 255, 255))
def move(self):
"""move worm."""
self.x += self.vx
self.y += self.vy
if (self.x, sel.y) in self.body:
self.crashed = True
self.body.insert(0, (self.x, self.y))
if len(self.body) > self.length:
self.body.pop()
def draw(self):
#for x, y self.body:
# self.surface.set_at((x, y),self.color)
x, y = self.body[0]
self.surface.set_at((x, y), self.color)
x, y = self.body[-1]
self.surface.set_at((x, y), (0, 0, 0))
width = 640
height = 400
screen = pygame.display.set_mode((width, height))
clock = pygame.time.Clock()
running = True
w = Worm(screen, width/2, height/2, 200)
while running:
screen.fill((0, 0, 0))
w.move()
w.draw()
if w.crashed or w.x <= 0 or w.x >= width -1 or w.y <= 0 or w.y >= height -1:
print "crash"
running = False
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
elif event.type == pygame.KEYDOWN:
w.key_event(event)
pygame.display.flip()
clock.tick(240)
和错误 -
Traceback (most recent call last):
File "C:/Users/Enrique/Dropbox/Public/snakegametutorial.py", line 65, in <module>
w.move()
File "C:/Users/Enrique/Dropbox/Public/snakegametutorial.py", line 34, in move
self.x += self.vx
AttributeError: Worm instance has no attribute 'vx'
2 个回答
0
dir_x 和 dir_y 其实就是 vx 和 vy，你应该把它们改成 vx 和 vy...
3
AttributeError 是一种错误，表示你试图访问一个对象中没有定义的属性或方法。
看起来你在教程的代码中还没有走得够远，所以还没有定义 Worm.move() 这个方法。这个方法在教程的第43行，正好在 Worm.draw() 之前。你还会遇到另一个 AttributeError，因为你还没有定义 draw() 方法。只需要把这两个方法添加到 Worm 类的定义中。
43 def move(self):
44 """ Move the worm. """
45 self.x += self.vx
46 self.y += self.vy
47
48 if (self.x, self.y) in self.body:
49 self.crashed = True
50
51 self.body.insert(0, (self.x, self.y))
52
53 if (self.grow_to > self.length):
54 self.length += 1
55
56 if len(self.body) > self.length:
57 self.body.pop()
58
59 def draw(self):
60 #for x, y in self.body:
61 # self.surface.set_at((x, y), self.color)
62 x, y = self.body[0]
63 self.surface.set_at((x, y), self.color)
64 x, y = self.body[-1]
65 self.surface.set_at((x, y), (0, 0, 0))
更新
现在你在 Worm.vx 上遇到了 AttributeError，因为你在 Worm.__init__() 中缺少了这个属性（还有 vy）。你可以把你的代码和教程页面上改进后的游戏部分的代码进行对比。当你遇到其他错误时，也可以把你的类定义和教程中的进行对比。
添加到 __init__()
def __init__(self, surface):
...
...
self.vx = 0
self.vy = -1
...
...