11.测试代码

测试代码

测试函数

核实一系列输入是否能得到预期的输出

name_function.py

def get_formatted_name(first, last):
    """Generate a neatly formatted full name."""
    full_name = first + ' ' + last
    return full_name.title()

name.py

from name_function import get_formatted_name

while True:
    first = input("\nPlease give me a first name: ")
    if first == 'q':
        break
    last = input("Please give me a last name: ")
    if last == 'q':
        break
    formatted_name = get_formatted_name(first, last)
    print("\tNeatly formated name: " + formatted_name + '.')

单元测试和测试用例

可通过的测试

test_name_function.py

import unittest
from name_function import get_formatted_name

class NamesTestCase(unittest.TestCase):
    """测试name_function.py"""

    def test_fist_last_name(self):
        """能够正确地处理像Janis Joplin这样的姓名吗"""
        formatted_name = get_formatted_name('janis', 'joplin')
        self.assertEqual(formatted_name, 'Janis Joplin')

unittest.main()

输出：

运行时，所有以test打头的方法都会自动运行

输出中，第一个句点表明有一个测试通过了。接下来的一行指出Python运行了一个测试，消耗的时间不到0.001秒。最好OK表明该测试用例中的所有单元测试都通过了

不能通过的测试

name_function.py

def get_formatted_name(first, middle, last):
    """生成整洁的姓名"""
    full_name = first + ' ' + middle + ' ' + last
    return full_name.title()

运行test_name_function.py输出：

E：指出测试用例中有一个单元测试导致了错误

ERROR：指出哪个单元测试出错

Traceback：指出错误的原因

测试未通过时怎么办

不要修改测试，而应修复导致测试不能通过的代码

name_function.py

def get_formatted_name(first,  last, middle=''):
    """生成整洁的姓名"""
    if middle:
        full_name = first + ' ' + middle + ' ' + last
    else:
        full_name = first + ' ' + last
    return full_name.title()

添加新测试

添加一个测试，用于测试包含中间名的姓名

import unittest
from name_function import get_formatted_name

class NamesTestCase(unittest.TestCase):
    """测试name_function.py"""

    def test_first_last_name(self):
        """能够正确地处理像Janis Joplin这样的姓名吗"""
        formatted_name = get_formatted_name('janis', 'joplin')
        self.assertEqual(formatted_name, 'Janis Joplin')

    def test_first_last_middle_name(self):
        """能够正确地处理像Wolfwang Amadeus Mozart这样的姓名吗"""
        formatted_name = get_formatted_name('wolfwang', 'mozart', 'amadeus')
        self.assertEqual(formatted_name, 'Wolfwang Amadeus Mozart')

unittest.main()

输出：

两个单元测试都通过

测试类

各种断言方法

返回值为Ture或False

方法	用途
assertEqual(a, b)	核实a == b
assertNotEqual(a, b)	核实a != b
assertTrue(x)	核实x为Ture
assertFalse(x)	核实x为False
assertIn(item, list)	核实item在list中
assertNotIn(item, list)	核实item不在list中

一个要测试的类

survey.py

class AnonymousSurvey():
    """收集匿名调查问卷的答案"""

    def __init__(self, question):
        """存储一个问题，并为存储答案做准备"""
        self.question = question
        self.responses = []

    def show_question(self):
        """显示调查问卷"""
        print(self.question)
        
    def store_response(self, new_response):
        """存储单份调查问卷"""
        self.responses.append(new_response)
        
    def show_results(self):
        """显示收集到的所有答卷"""
        print("Survey results: ")
        for response in self.responses:
            print('- ' + response)

测试AnonymousSurvey类

import unittest
from survey import AnonymousSurvey

class TestAnonymousSurvey(unittest.TestCase):
    """针对AnonymousSurvey类的测试"""

    def test_store_single_response(self):
        """测试单个答案会被妥善地存储"""
        question = "What language did you first learn to speak?"
        my_survey = AnonymousSurvey(question)
        my_survey.store_response('English')

        self.assertIn('English', my_survey.responses)

    def test_store_three_response(self):
        """测试三个答案会被妥善地存储"""
        question = "What language did you first learn to speak?"
        my_survey = AnonymousSurvey(question)
        responses = ['English', 'Spanish', 'Mandarin']
        for response in responses:
            my_survey.store_response(response)

        for response in responses:
            self.assertIn(response, my_survey.responses)

unittest.main()

方法setUp()

unittest.TestCase类包含方法setUp()

只需创建这些对象一次，并在每个测试方法中使用它们

如果TestCase类中包含方法setUp()，Python将先运行它，再运行各个以test_打头地方法

import unittest
from survey import AnonymousSurvey

class TestAnonymousSurvey(unittest.TestCase):
    """针对AnonymousSurvey类的测试"""

    def setUp(self):
        """
        创建一个调查对象和一组答案，供使用地测试方法使用
        """
        question = "What language did you first learn to speak?"
        self.my_survey = AnonymousSurvey(question)
        self.responses = ['English', 'Spanish', 'Mandarin']

    def test_store_single_response(self):
        """测试单个答案会被妥善地存储"""
        self.my_survey.store_response('English')
        self.assertIn(self.responses[0], self.my_survey.responses)

    def test_store_three_response(self):
        """测试三个答案会被妥善地存储"""
        for response in self.responses:
            self.my_survey.store_response(response)

        for response in self.responses:
            self.assertIn(response, self.my_survey.responses)

unittest.main()

能够提高效率，减少重复