Dive Into Python: call for comments (long)
Steve Purcell
stephen_purcell at yahoo.com
Tue Apr 24 02:58:30 EDT 2001
Mark Pilgrim wrote:
> Chapter 4 of "Dive Into Python" ( http://diveintopython.org/ ) is almost
> done, and I would like to devote Chapter 5 to PyUnit (
> http://pyunit.sourceforge.net/ ), the new unit testing framework included in
> Python 2.1. This is a general call for help to anyone who has had
> experience writing unit tests in other platforms (or worked with PyUnit in
> particular), and anyone who has opinions about my Python coding style and
> The Pythonic Way.
Mark: I'd be happy to help out in any way I can. Just mail me privately.
I've included at the end of this mail an example of how *I* would write
romantest.py.
Some quick comments:
- You should find an example that has a clearer need for 'setUp' -- usually
setUp methods arise from the refactoring of several long test* methods
that do a lot of complicated initialisation before they start testing.
- main() is all you need to call in order to get all your tests to run
from the command-line, provided you name your test methods 'test*'
- assertEqual() already prints out a message "a != b" if it fails. I find
that writing long assertion messages is not a worthwhile effort because
the message should hopefully never appear. (More valuable are the names
of the test cases that fail.)
Best wishes,
-Steve
--
Steve Purcell, Pythangelist
Get testing at http://pyunit.sourceforge.net/
Any opinions expressed herein are my own and not necessarily those of Yahoo
---------romantest.py-------------------------
#!/usr/bin/python
"""Unit test for roman.py"""
__author__ = "Mark Pilgrim (f8dy at diveintopython.org)"
__version__ = "1.0"
__date__ = "21 April 2001"
import roman
import unittest
#-----------------
#Define test cases
#-----------------
class SanityCheck(unittest.TestCase):
"""test that fromRoman(toRoman(n))==n for all n"""
def testSanity(self):
"""test that fromRoman(toRoman(n))==n for all n"""
for n in range(1, 4000):
s = roman.toRoman(n)
fullcircle = roman.fromRoman(s)
self.assertEqual(n, fullcircle, \
"%(n)s --> %(s)s --> %(fullcircle)s" % locals())
class RomanTestCase(unittest.TestCase):
"""base class to set up tests that require a set of known values"""
knownValues = ((31, 'XXXI'),
(148, 'CXLVIII'),
(294, 'CCXCIV'),
(312, 'CCCXII'),
(421, 'CDXXI'),
(528, 'DXXVIII'),
(621, 'DCXXI'),
(782, 'DCCLXXXII'),
(870, 'DCCCLXX'),
(941, 'CMXLI'),
(1043, 'MXLIII'),
(1110, 'MCX'),
(1226, 'MCCXXVI'),
(1301, 'MCCCI'),
(1485, 'MCDLXXXV'),
(1509, 'MDIX'),
(1607, 'MDCVII'),
(1754, 'MDCCLIV'),
(1832, 'MDCCCXXXII'),
(1993, 'MCMXCIII'),
(2074, 'MMLXXIV'),
(2152, 'MMCLII'),
(2212, 'MMCCXII'),
(2343, 'MMCCCXLIII'),
(2499, 'MMCDXCIX'),
(2574, 'MMDLXXIV'),
(2646, 'MMDCXLVI'),
(2723, 'MMDCCXXIII'),
(2892, 'MMDCCCXCII'),
(2975, 'MMCMLXXV'),
(3051, 'MMMLI'),
(3185, 'MMMCLXXXV'),
(3250, 'MMMCCL'),
(3313, 'MMMCCCXIII'),
(3408, 'MMMCDVIII'),
(3501, 'MMMDI'),
(3610, 'MMMDCX'),
(3743, 'MMMDCCXLIII'),
(3844, 'MMMDCCCXLIV'),
(3940, 'MMMCMXL'))
def testConversionToKnownValues(self):
"""test toRoman with known values"""
for n, s in self.knownValues:
result = roman.toRoman(n)
self.assertEqual(s, result)
def testConversionFromKnownValues(self):
"""test fromRoman with known values"""
for n, s in self.knownValues:
result = roman.fromRoman(s)
self.assertEqual(n, result)
class ToRomanBadInput(unittest.TestCase):
"""test toRoman with a variety of bad inputs"""
def testTooLarge(self):
"""test toRoman with large input"""
self.assertRaises(roman.OutOfRangeError, roman.toRoman, 4000)
def testZero(self):
"""test toRoman with 0 input"""
self.assertRaises(roman.OutOfRangeError, roman.toRoman, 0)
def testNegative(self):
"""test toRoman with negative input"""
self.assertRaises(roman.OutOfRangeError, roman.toRoman, -1)
def testDecimal(self):
"""test toRoman with non-integer input"""
self.assertRaises(roman.NotIntegerError, roman.toRoman, 0.5)
class FromRomanBadInput(unittest.TestCase):
"""test fromRoman with a variety of bad inputs"""
def testTooManyRepeatedNumerals(self):
"""test fromRoman with too many repeated numerals"""
for s in ('MMMM', 'DD', 'CCCC', 'LL', 'XXXX', 'VV', 'IIII'):
self.assertRaises(roman.InvalidRomanNumeralError, roman.fromRoman, s)
def testRepeatedPairs(self):
"""test fromRoman with repeated pairs of numerals"""
for s in ('CMCM', 'CDCD', 'XCXC', 'XLXL', 'IXIX', 'IVIV'):
self.assertRaises(roman.InvalidRomanNumeralError, roman.fromRoman, s)
def testMalformedAntecedent(self):
"""test fromRoman with malformed antecedents"""
for s in ('IIMXCC', 'VX', 'DCM', 'CMM', 'IXIV',
'MCMC', 'XCX', 'IVI', 'LM', 'LD', 'LC'):
self.assertRaises(roman.InvalidRomanNumeralError, roman.fromRoman, s)
if __name__ == '__main__':
unittest.main()
More information about the Python-list
mailing list