1.各种断言方法

　　常用断言方法：

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

2.一个要测试的类

　　首先编写一个类：

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_quetion(self):
        """显示调查问卷"""
        print(self.question)

    def store_response(self, new_response):
        """存储单份调查答案"""
        self.responses.append(new_response)

    def show_result(self):
        """显示收集到的所有答卷"""
        print("Survey result:")
        for response in self.responses:
            print('- ' + response)

　　为证明AnonymousSurvey类可以正确的工作，编写一个使用它的程序：

language_survey.py

---

from survey import AnonymousSurvey

# 定义一个问题，并创建一个表示调查的AnonymousSurvey对象
question = "What language did you first learn to speak?"
my_survey = AnonymousSurvey(question)

# 显示并存储问题的答案
my_survey.show_quetion()
print("Enter 'q' at any time to quit.\n")
while True:
    response = input("Language: ")
    if response == 'q':
        break
    my_survey.store_response(response)

# 显示调查结果
print("\nThank you to everyone who participated in survey!")
my_survey.show_result()

　　运行结果：

What language did you first learn to speak?
Enter 'q' at any time to quit.

Language: English
Language: Spanish
Language: English
Language: Mandarin
Language: q

Thank you to everyone who participated in survey!
Survey result:
- English
- Spanish
- English
- Mandarin

3.测试AnonymousSurvey类

　　对AnonymousSurvey类行为的一个方面进行验证：如果用户面对调查问题时只提供了一个答案，这个答案也能被妥善地存储。使用方法assertIn()来核实它包含在答案列表中：

test_survey.py

---

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)


if __name__ == "__main__":
    unittest.main()

　　运行test_survey.py时，测试通过了：

Ran 1 test in 0.010s

OK

　　只能收集一个答案的调查用途不大。下面核实用户提供三个答案时，它们也将被妥善地存储。为此，在AnonymousSurvey中再添加一个方法：

import unittest
from survey import AnonymousSurvey


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

    def test_store_single_response(self):
        ...

    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)


if __name__ == "__main__":
    unittest.main()        

　　再次运行test_survey.py时，两个测试都通过了：

Ran 2 te