什么是错误消息 - (AttributeError:蠕虫实例没有属性'vx')意味着我该如何解决?

时间:2011-10-22 01:31:09

标签: python pygame

我一直关注a tutorial,但一直收到以下错误 AttributeError: Worm instance has no attribute 'move'
我不确定它究竟是什么意思或如何解决它。该错误指的是第44行朝向底部,该行为w.move() (此解决方案如下所示)

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)

----------改变--------

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 个答案:

答案 0 :(得分:3)

AttributeError表示您试图访问未在对象的类定义中定义的对象上的属性或方法。

看起来您在教程代码中没有取得足够的进展来定义Worm.move()方法。它出现在本教程的第43行,就在Worm.draw()之前。您将前往AttributeError方法的另一个draw(),因为您尚未定义该方法。只需将这两个添加到Worm类定义中。

 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))

<强>更新

您现在收到AttributeError上的Worm.vx,因为您错过了vy的该属性(也是Worm.__init__())。将您的代码与教程页面上改进游戏标题下的代码进行比较。当您遇到更多错误时,请将您的班级定义与教程进行比较。

添加到__init__()

def __init__(self, surface):
    ...
    ...
    self.vx = 0
    self.vy = -1
    ...
    ...

答案 1 :(得分:0)

dir_xdir_y是vx和vy你应该改变它们......到vx和vy ......