python-unittest(1)

绿色的麦田

<div id="cnblogs_post_body">一个非常简单的python的测试用例，取自电子书：《Python Testing Cookbook》第一章内容，里面说的足够简单明了，将之摘出来，对照代码，应该很容易理解。
The basic concept of an automated unittest test case is to instantiate part of our code,
subject it to operations, and verify certain results using assertions.
1. If the results are as expected, unittest counts it as a test success
2. If the results don't match, an exception is thrown and unittest counts it as a
test failure
With these steps, we will code a simple program and then write some automated tests
using unittest:
1. Create a new file called recipe1.py in which to put all of this recipe's code. Pick a
class to test. This is known as the class under test. For this recipe, we'll pick a class
that uses a simplistic Roman numeral converter:
2. Write a new class and give it the same name with Test appended to the end,
subclassing unittest.TestCase. Appending a test class with Test is a common
convention, but not a requirement. Extending unittest.TestCase is a requirement
needed to hook into unittest's standard test runner.
3. Create several methods whose names start with test, so they are automatically
picked up by the test number of unittest.
4. Make the entire script runnable and then use unittest's test runner.
if __name__ == "__main__":
unittest.main()
5. Run the file from the command line.
  
附测试代码：
  <div class="cnblogs_code">Code<span style="display: none" id="Code_Open_Text_437531"># !usr/bin/env python 2.7# coding: utf-8# filename: recipe1.pyclass RomanNumeralConverter(object):    def __init__(self, roman_numeral):        self.roman_numeral = roman_numeral        self.digit_map = {"M":1000, "D":500, "C":100, "L":50, "X":10, "V":5, "I":1}    def convert_to_decimal(self):        val = 0        for char in self.roman_numeral:            val += self.digit_map[char]        return valimport unittestclass RomanNumeralConverterTest(unittest.TestCase):    def test_parsing_millenia(self):        value = RomanNumeralConverter("M")        self.assertEquals(1000, value.convert_to_decimal())    def test_parsing_century(self):        value = RomanNumeralConverter("C")        self.assertEquals(100, value.convert_to_decimal())    def test_parsing_half_century(self):        value = RomanNumeralConverter("L")        self.assertEquals(50, value.convert_to_decimal())    def test_parsing_decade(self):        value = RomanNumeralConverter("X")        self.assertEquals(10, value.convert_to_decimal())    def test_parsing_half_decade(self):        value = RomanNumeralConverter("V")        self.assertEquals(5, value.convert_to_decimal())    def test_parsing_one(self):        value = RomanNumeralConverter("I")        self.assertEquals(1, value.convert_to_decimal())    def test_empty_roman_numeral(self):        value = RomanNumeralConverter("")        self.assertTrue(value.convert_to_decimal() == 0)        self.assertFalse(value.convert_to_decimal() > 0)    def test_no_roman_numeral(self):        value = RomanNumeralConverter(None)        self.assertRaises(TypeError, value.convert_to_decimal)if __name__ == "__main__":    unittest.main()