导航:起始页 > Dive Into Python > 测试优先编程 > roman.py, 第 3 阶段 | << >> | ||||
深入 Python :Dive Into Python 中文版Python 从新手到专家 [Dip_5.4b_CPyUG_Release] |
现在 toRoman 对于有效的输入 (1 到 3999 整数) 已能正确工作,是正确处理那些无效输入 (任何其他输入) 的时候了。
这个文件可以在例子目录下的 py/roman/stage3/ 目录中找到。
如果您还没有下载本书附带的样例程序, 可以 下载本程序和其他样例程序。
"""Convert to and from Roman numerals""" #Define exceptions class RomanError(Exception): pass class OutOfRangeError(RomanError): pass class NotIntegerError(RomanError): pass class InvalidRomanNumeralError(RomanError): pass #Define digit mapping romanNumeralMap = (('M', 1000), ('CM', 900), ('D', 500), ('CD', 400), ('C', 100), ('XC', 90), ('L', 50), ('XL', 40), ('X', 10), ('IX', 9), ('V', 5), ('IV', 4), ('I', 1)) def toRoman(n): """convert integer to Roman numeral""" if not (0 < n < 4000): raise OutOfRangeError, "number out of range (must be 1..3999)" if int(n) <> n: raise NotIntegerError, "non-integers can not be converted" result = "" for numeral, integer in romanNumeralMap: while n >= integer: result += numeral n -= integer return result def fromRoman(s): """convert Roman numeral to integer""" pass
>>> import roman3 >>> roman3.toRoman(4000) Traceback (most recent call last): File "<interactive input>", line 1, in ? File "roman3.py", line 27, in toRoman raise OutOfRangeError, "number out of range (must be 1..3999)" OutOfRangeError: number out of range (must be 1..3999) >>> roman3.toRoman(1.5) Traceback (most recent call last): File "<interactive input>", line 1, in ? File "roman3.py", line 29, in toRoman raise NotIntegerError, "non-integers can not be converted" NotIntegerError: non-integers can not be converted
fromRoman should only accept uppercase input ... FAIL toRoman should always return uppercase ... ok fromRoman should fail with malformed antecedents ... FAIL fromRoman should fail with repeated pairs of numerals ... FAIL fromRoman should fail with too many repeated numerals ... FAIL fromRoman should give known result with known input ... FAIL toRoman should give known result with known input ... ok fromRoman(toRoman(n))==n for all n ... FAIL toRoman should fail with non-integer input ... ok toRoman should fail with negative input ... ok toRoman should fail with large input ... ok toRoman should fail with 0 input ... ok
toRoman 仍然能通过已知值测试,这很令人鼓舞。所有第 2 阶段通过的测试仍然能通过,这说明新的代码没有对原有代码构成任何负面影响。 | |
更令人振奋的是所有的无效输入测试现在都通过了。testNonInteger 这个测试能够通过是因为有了 int(n) <> n 检查。当一个非整数传递给 toRoman 时,int(n) <> n 检查出问题并引发 NotIntegerError 异常,这正是 testNonInteger 所期待的。 | |
testNegative 这个测试能够通过是因为 not (0 < n < 4000) 检查引发了 testNegative 期待的 OutOfRangeError 异常。 |
====================================================================== FAIL: fromRoman should only accept uppercase input ---------------------------------------------------------------------- Traceback (most recent call last): File "C:\docbook\dip\py\roman\stage3\romantest3.py", line 156, in testFromRomanCase roman3.fromRoman, numeral.lower()) File "c:\python21\lib\unittest.py", line 266, in failUnlessRaises raise self.failureException, excName AssertionError: InvalidRomanNumeralError ====================================================================== FAIL: fromRoman should fail with malformed antecedents ---------------------------------------------------------------------- Traceback (most recent call last): File "C:\docbook\dip\py\roman\stage3\romantest3.py", line 133, in testMalformedAntecedent self.assertRaises(roman3.InvalidRomanNumeralError, roman3.fromRoman, s) File "c:\python21\lib\unittest.py", line 266, in failUnlessRaises raise self.failureException, excName AssertionError: InvalidRomanNumeralError ====================================================================== FAIL: fromRoman should fail with repeated pairs of numerals ---------------------------------------------------------------------- Traceback (most recent call last): File "C:\docbook\dip\py\roman\stage3\romantest3.py", line 127, in testRepeatedPairs self.assertRaises(roman3.InvalidRomanNumeralError, roman3.fromRoman, s) File "c:\python21\lib\unittest.py", line 266, in failUnlessRaises raise self.failureException, excName AssertionError: InvalidRomanNumeralError ====================================================================== FAIL: fromRoman should fail with too many repeated numerals ---------------------------------------------------------------------- Traceback (most recent call last): File "C:\docbook\dip\py\roman\stage3\romantest3.py", line 122, in testTooManyRepeatedNumerals self.assertRaises(roman3.InvalidRomanNumeralError, roman3.fromRoman, s) File "c:\python21\lib\unittest.py", line 266, in failUnlessRaises raise self.failureException, excName AssertionError: InvalidRomanNumeralError ====================================================================== FAIL: fromRoman should give known result with known input ---------------------------------------------------------------------- Traceback (most recent call last): File "C:\docbook\dip\py\roman\stage3\romantest3.py", line 99, in testFromRomanKnownValues self.assertEqual(integer, result) File "c:\python21\lib\unittest.py", line 273, in failUnlessEqual raise self.failureException, (msg or '%s != %s' % (first, second)) AssertionError: 1 != None ====================================================================== FAIL: fromRoman(toRoman(n))==n for all n ---------------------------------------------------------------------- Traceback (most recent call last): File "C:\docbook\dip\py\roman\stage3\romantest3.py", line 141, in testSanity self.assertEqual(integer, result) File "c:\python21\lib\unittest.py", line 273, in failUnlessEqual raise self.failureException, (msg or '%s != %s' % (first, second)) AssertionError: 1 != None ---------------------------------------------------------------------- Ran 12 tests in 0.401s FAILED (failures=6)
全面的单元测试能够告诉你的最重要的事情是什么时候停止编写代码。当一个函数的所有单元测试都通过了,停止编写这个函数。一旦整个模块的单元测试通过了,停止编写这个模块。 |
<< roman.py, 第 2 阶段 |
| 1 | 2 | 3 | 4 | 5 | |
roman.py, 第 4 阶段 >> |