Question

我正在努力练习学习Python，我收到的错误是：

Traceback (most recent call last):
File "c:\python26\lib\site-packages\nose-1.2.0-py2.6.egg\nose
97, in runTest
self.test(*self.arg)
File "E:\project\ex47\tests\ex47_tests.py", line 27, in test_
assert_equal(start.go('down').go('up'),start)
AssertionError: None != <ex47.game.Room object at 0x0191BFD0>

#while executing the below code: 

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

我在Google上搜索并发现它在调试时被引发但是也可能导致我的game.py文件位于bin文件夹中

整体结构就像这样

项目/ ex47 /箱/
/文档
/tests/ex47_tests.py,_ _ init_ _ .py
/ex47/game.py

谁能帮帮我，告诉我为什么会收到这个错误？

这是game.py文件。

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)

Answer 1

您从未向up会议室添加down路径。

down = Room("Dungeon","It's dark down here, you can go up.")

所以你的失败就在这条线上

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

start.go('down')返回down Room对象，该对象没有up的路径。它会从None调用返回get()，并再次比较start对象。因为None != start

而引发了断言

看起来你需要这一行：

down.add_paths({'up', start})

Answer 2

您没有显示您正在测试的实际代码，但某些地方可能缺少return语句。

在进行LPTHW练习时得到断言错误

2 个答案: