Question

I’m doing example 47 from "Learn Python the hard way".

And this is my 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})
    down.add_paths({'up': start})

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

However, when testing this code using nosetest I get an error:

Traceback <most recent call last>:
File "c:\Python31\lib\site-packages\nose\case.py", line 197,in runtest
    self.test<*self.arg>
File "C:\path\Ex47\skeleton\tests\ex47_tests.py", line 28, in test_map
    start.add_paths<{'west': west, 'down':down>}
AttributeError: 'Room' object has no attribute 'add_paths'

---

Ran 3 tests in 0.030s

FAILED <errors=2>

This seems to be ridiculous since add_paths worked fine in test_room_paths().

I’m using Python 3.1, Windows 7.

Here is the code for game.py just in case you need it:

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

You state, “add_paths worked fine in test_room_paths()”, but you are assuming the tests are run in the order you’ve written them. They often are run in alphabetical order, meaning test_room_paths hasn’t executed yet.

Your Room code looks incorrect, you have def add_paths indented under def __init__, meaning add_paths is a function defined locally in __init__, rather than another method in your class. Be sure all the def keywords in your class are lined up.