編程自己常見error（4）

編程自己常見error（4）

15、關於寫測試文件時候的路經測試

在學習練習47的時候，我按照文中的測試代碼寫了小腳本以及測試文件，但是總是有錯誤，而且我還是沒有檢查出錯誤來，隔了兩天，我終於看出來了，主要就是經驗不足的小錯誤，但還是值得學一下。
錯誤代碼：(game.py)

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)
		

測試文件（BLAH_test.py）：

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("Tress ", "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)
#def setup():
#	print "SETUP!"

#def teardown():
#	print "TEAR DOWN!"

#def test_basic():
#	print "I RAN!"

顯示結果是：

PS C:\Users\15222\lpthw\ex47\skeleton> nosetests
.EE
======================================================================
ERROR: tests.BLAH_tests.test_room_paths
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Python27\lib\site-packages\nose-1.3.7-py2.7.egg\nose\case.py", line 197, in runTest
    self.test(*self.arg)
  File "C:\Users\15222\lpthw\ex47\skeleton\tests\BLAH_tests.py", line 16, in test_room_paths
    center.add_paths({'north':north, 'south':south})
  File "C:\Users\15222\lpthw\ex47\skeleton\ex47\game.py", line 12, in add_paths
    self.paths.update(paths)
AttributeError: 'list' object has no attribute 'update'

======================================================================
ERROR: tests.BLAH_tests.test_map
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Python27\lib\site-packages\nose-1.3.7-py2.7.egg\nose\case.py", line 197, in runTest
    self.test(*self.arg)
  File "C:\Users\15222\lpthw\ex47\skeleton\tests\BLAH_tests.py", line 26, in test_map
    'down': down})
  File "C:\Users\15222\lpthw\ex47\skeleton\ex47\game.py", line 12, in add_paths
    self.paths.update(paths)
AttributeError: 'list' object has no attribute 'update'

----------------------------------------------------------------------
Ran 3 tests in 0.027s

FAILED (errors=2)
PS C:\Users\15222\lpthw\ex47\skeleton>

報的錯誤是;列表沒有update操作。於是我當時就很蒙，因爲他一直提示的是BLASH_test.py中的錯誤，我就檢查對應的行，但是就是用的花括號，是字典類型，肯定是有update操作的。檢查了一個多小時，沒有檢查出來。
今天我重新看代碼的時候，發現是game.py中的path產生了錯誤，用的是列表（是[ ]），終於發現了這個錯誤。
想法就是：報的錯誤雖然是那裏，但是可能那裏沒有錯，而是和他相關的地方錯了！！

修正後的：
正確代碼：

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)
		

測試文件：

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("Tress ", "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)
#def setup():
#	print "SETUP!"

#def teardown():
#	print "TEAR DOWN!"

#def test_basic():
#	print "I RAN!"

顯示結果：

PS C:\Users\15222\lpthw\ex47\skeleton> nosetests
...
----------------------------------------------------------------------
Ran 3 tests in 0.026s

OK
PS C:\Users\15222\lpthw\ex47\skeleton>

大功告成！！！