我有一个编译错误“未定义”，尽管有定义

Question

  from gasp import *
GRID_SIZE = 30
MARGIN = GRID_SIZE

BACKGROUND_COLOR = color.BLACK    # Colors we use
WALL_COLOR = (0.6 * 255, 0.9 * 255, 0.9 * 255)

# The shape of the maze.  Each character
# represents a different type of object
#   % - Wall
#   . - Food
#   o - Capsule
#   G - Ghost
#   P - Chomp
# Other characters are ignored


the_layout = [
  "%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%",    
  "%.....%.................%.....%",
  "%o%%%.%.%%%.%%%%%%%.%%%.%.%%%o%",
  "%.%.....%......%......%.....%.%",
  "%...%%%.%.%%%%.%.%%%%.%.%%%...%",
  "%%%.%...%.%.........%.%...%.%%%",
  "%...%.%%%.%.%%% %%%.%.%%%.%...%",
  "%.%%%.......%GG GG%.......%%%.%",
  "%...%.%%%.%.%%%%%%%.%.%%%.%...%",
  "%%%.%...%.%.........%.%...%.%%%",
  "%...%%%.%.%%%%.%.%%%%.%.%%%...%",
  "%.%.....%......%......%.....%.%",
  "%o%%%.%.%%%.%%%%%%%.%%%.%.%%%o%",
  "%.....%........P........%.....%",
  "%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%"]


class Immovable:
    def is_a_wall(self):
        return False

class Nothing(Immovable):
    pass

class Maze:
    def __init__(self):
        self.have_window = False
        self.game_over = False
        self.set_layout(the_layout)
        set_speed(20)

    def set_layout(self, layout):
        height = len(layout)                   
        width = len(layout[0])                
        self.make_window(width, height)
        self.make_map(width, height)         
        max_y = height - 1
        for x in range( width ):     
            for y in range(height):
                char = layout[max_y - y][x]   
                self.make_object((x, y), char) 

    def make_window(self, width, height):
        grid_width = (width -1) * GRID_SIZE
        grid_height = (height - 1) * GRID_SIZE
        screen_width = 2 * MARGIN + grid_width
        screen_height = 2 *  MARGIN + grid_height
        begin_graphics(screen_width, screen_height,"Chomp",BACKGROUND_COLOR)

    def to_screen(self, point):
        (x,y) = point
        x = x * GRID_SIZE + MARGIN
        y = y * GRID_SIZE + MARGIN
        return(x,y)

    def make_map(self, width, height):
        self.width = width
        self.height = height
        self.map = []
        for y in range(width):
            new_row = []
            for x in range(width):
                new_row.append(Nothing())
            self.map.append(new_row)

    def make_object(self,point,charactor):
        (x,y) = point
        if charactor == "%":
            self.map[y][x] = Wall(self,point)

    def finished(self):
        return self.game_over

    def play(self):
        update_when('next_tick')

    def done(self):
        end_graphics()
        self.map = []

    def object_at(self,point):
        (x,y) = point
        if y < 0 or y >= self.height:
            return Nothing()
        if x < 0 or x >= self.width:
            return Nothing()
        return self.map[y][x]




class Wall(Immovable):
    def __init__(self, maze, point):
        self.place = point                          # Store our position
        self.screen_point = maze.to_screen(point)
        self.maze = maze                            # Keep hold of Maze
        self.draw()

    def draw(self):
        (screen_x, screen_y) = self.screen_point
        dot_size = GRID_SIZE * 0.2
        Circle(self.screen_point, dot_size,   
                color = WALL_COLOR, filled = 1)
        (x, y) = self.place
        neighbors = [ (x+1, y), (x-1, y)]
        for neighbor in neighbors:
            self.check_neighbor(neighbor)

    def check_neighbor(self,neighbor):
        maze = self.maze
        object = maze.object_at(neighbor)

        if object.is_a_wall():
            here = self.screen_point
            there = maze.to_screen(neighbor)
            Line(here, there, color = WALL_COLOR,thickness = 2)

    def is_a_wall(self):
        return True

the_maze = Maze()

while not the_maze.finished():
    the_maze.play()
    the_maze.done()

我遇到了这个错误..

Traceback (most recent call last):  
File "chomp.py", line 110, in class Wall(Immovable):
File "chomp.py", line 124, in Wall for neighbor in neighbors:
NameError: name 'neighbors' is not defined

我花了很多时间还是找不到问题出在哪里，需要一些帮助。

Answer 1

我一下子看不出哪里出错了。你最近有没有移动过文件，导致某个导入的代码其实没有运行你新的代码，而是运行了一个.pyc文件？比如说，你最近是不是引入了一个和某个Python文件同名的包？

.
\- main.py           Has an "import stuff"
\- stuff.py          This is the code you think is being run.
\- stuff
   \- __init__.py    This code is being run.

Answer 2

你提到的未完成的 Circle() 调用，可能是因为在格式化代码时出现了错误。请确认你发布的代码是你实际运行的代码，并且错误信息是你真实得到的（这里面有一些信息缺失！）。

在错误信息中（格式很糟糕），提到在这一行 for neighbor in neighbors: 中，neighbors 是未定义的。编译器绝对不可能在中间的行中顺利通过而没有其他错误。

(x, y) = self.place
neighbors = [ (x+1, y), (x-1, y)]

没有其他错误的话，它是不会继续执行的。

注意：上面的内容是对另一个问题的回应，而那个问题在我回答的时候已经被关闭了。 我把它留在这里是为了让你知道，你在那个问题上得到的建议是错误的。

我怀疑在你提到的 第一个问题 中（在 for x in range( width ): 这一行中 width 没有定义），你没有修复所有的缩进错误，而在 Q2 和 Q3 中的 for neighbor in neighbors: 这一行应该向右移动 4 个空格。

你的源文件中有没有制表符？如果有，赶紧去掉它们。 如果你不确定怎么保持文件中没有制表符，可以单独提问，说明你使用的编辑器和操作系统，或许有人能帮你。

如何在源文件中查找制表符：

C:\junk>\python27\python -c "print[x for x in enumerate(open('sometabs.py'),1)if'\t'in x[1]]"
[(1, 'foo\tbar\n'), (3, '\t\toof\n')]