Question

我正在通过LPTHW工作，并且遇到Ex47的属性错误。我查看了这个网站并搜索谷歌寻求帮助，但似乎找不到任何东西。

我得到的错误是：

  Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/Users/Donatron/temp/My Python Stuff/projects/ex47/tests/ex47_tests.py", line 26, in test_map
    start.add_paths({'west': west, 'down': down})
  File "/Users/Donatron/temp/My Python Stuff/projects/ex47/ex47/game.py", line 12, in add_paths
    self.paths.update(paths)
AttributeError: 'list' object has no attribute 'update'

我的游戏＆＃34;代码如下所示： -

class Room(object):


    def __init__(self, name, description):
        self.name = name
        self.description = description
        self.paths = []

    def go(self, direction):
        return self.paths.get(direction, None)

    def add_paths(self, paths):
        self.paths.update(paths)

我的＆＃34;测试＆＃34;代码如下所示： -

from nose.tools import *
from ex47.game import Room

def test_room():
    gold = Room("GoldRoom",
                """This room has gold in it you can grab. There's a
                door to the north.""")
    assert_equal(gold.name, "GoldRoom")
    assert_equal(gold.paths, [])

def test_room_paths():
    center = Room("Center", "Test room in the center.")
    north = Room("North", "Test room in the north.")
    south = Room("South", "Test room in the south.")

    center.add_paths({'north': north, 'south': south})
    assert_equal(center.go('north'), north)
    assert_equal(center.go('south'), south)

def test_map():
    start = Room("Start", "You can go west and down a hole.")
    west = Room("Trees", "There are trees here, you can go east.")
    down = Room("Dungeon", "It's dark down here, you can go up.")

    start.add_paths({'west': west, 'down': down})
    west.add_paths({'east': start})
    down.add_paths({'up': start})

    assert_equal(start.go('west'), west)
    assert_equal(start.go('west').go('east'), start)
    assert_equal(start.go('down').go('up'), start)

这是我的头！我哪里错了？

提前感谢您的帮助： - ）

Answer 1

self.paths应该是dict {}而不是列表

self.paths = {}

dicts有get和update种方法，您的self.paths是一个没有更新方法的列表[]，这就是为什么你会得到错误。

在错误的最后，您可以看到start.add_paths({'west': west, 'down': down})正在添加传递给self.paths的dict，该dict尝试调用self.paths.update方法，但因self.paths而失败，设置为list而不是dict {}。

return self.paths.get(direction, None)＃使用dict.get方法

self.paths.update(paths)＃使用dict.update方法。

如果dict.get(direction, None)中不存在None，则默认情况下

key会返回dict，您可以指定任何默认返回值来代替None。

LPTHW Ex47属性错误

1 个答案: