python-测试代码

1. 测试函数

get_name.py

def combination(first, last):
    '''将姓名组合在一起'''
    name = first + ' ' + last
    return name.title()

hello_world.py

from get_name import combination

print("Enter 'q' to quit!")
while True:
    first = input('Please input your first name: ')
    if first == 'q':
        break
    last = input('Please input your last name: ')
    if last == 'q':
        break
    name = combination(first, last)
    print(name)

# Enter 'q' to quit!
# Please input your first name: tom
# Please input your last name: riddle
# Tom Riddle
# Please input your first name: q

1.1. 单元测试和测试用例

• 单元测试：用于核实函数的某个方面没有问题。

• 测试用例：是一组单元测试，这些单元测试一起核实函数在各种情形下的行为都符号要求。

• 全覆盖式侧式用例：包含一整套单元测试，涵盖了各种可能的函数使用方式。

1.1.1 可通过的测试

注意：

• 导入模块unittest以及要测试的函数

• 创建一个继承unittest.TestCase的类，编写一系列方法对函数行为的不同方面进行测试

• 方法名使用test_或test，会在我们运行.py时自动运行这个方法

• 断言方法，即调用unittest的方法assertEqual(测试的结果，期望的结果)

• 在最后加上 if name=='main' : unittest.main()

get_name.py

def combination(first, last):
    '''将姓名组合在一起'''
    name = first + ' ' + last
    return name.title()

hello_world.py

from get_name import combination

print("Enter 'q' to quit!")
while True:
    first = input('Please input your first name: ')
    if first == 'q':
        break
    last = input('Please input your last name: ')
    if last == 'q':
        break
    name = combination(first, last)
    print(name)

# Enter 'q' to quit!
# Please input your first name: tom
# Please input your last name: riddle
# Tom Riddle
# Please input your first name: q

test_name.py

import unittest
from get_name import combination

class TestName(unittest.TestCase):
    def test_name(self):
        result_name = combination('harry', 'potter')
        self.assertEqual(result_name, 'Harry Potter')

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

# Ran 1 test in 0.008s
# OK

1.1.2 不能通过的测试

get_name.py

def combination(first, middle, last):
    '''将姓名组合在一起'''
    name = first + ' ' + middle + ' ' + last
    return name.title()

再次运行test_name.py，运行结果如下：

1.1.3 测试未通过时进行处理

修改get_name.py

def combination(first, last, middle=''):
    '''将姓名组合在一起'''
    if middle:
        name = first + ' ' + middle + ' ' + last
    else:
        name = first + ' ' + last
    return name.title()

test_name.py运行结果：

1.1.4 添加新测试

注意：测试类中的函数名要带有描述性，这样才能明白测试未通过时的输出

test_name.py

import unittest
from get_name import combination

class TestName(unittest.TestCase):
    def test_name(self):
        result_name = combination('harry', 'potter')
        self.assertEqual(result_name, 'Harry Potter')

    def test_middle_name(self):
        result_name = combination('li', 'xiao', 'ming')
        self.assertEqual(result_name, 'Li Ming Xiao')

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

# Ran 2 tests in 0.002s
# OK

2. 测试类

2.1. 各种断言方法

unittest.TestCase类中提供了很多断言的方法：

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

assertIn(item,list)

核实item在list中

assertNotIn(item,list)

核实item不在list中

2.2. 一个要测试的类

investigate.py

class Investigation():
    '''调查问卷'''

    def __init__(self, question):
        self.question = question
        self.responses = []

    def show_question(self):
        print(self.question)

    def store_new_response(self, new_response):
        self.responses.append(new_response)

    def show_results(self):
        for response in self.responses:
            print(response)

language_investigate.py

from investigate import Investigation

question = '你喜欢哪种编程语言？'
my_investigate = Investigation(question)
my_investigate.show_question()
print("Enter 'q' to quit!")
while True:
    response = input('Language: ')
    if response == 'q':
        break
    my_investigate.store_new_response(response)
my_investigate.show_results()
# 你喜欢哪种编程语言？
# Enter 'q' to quit!
# Language: Python
# Language: C
# Language: q
# Python
# C

2.3. 测试Investigation类

investigate_test.py

import unittest
from investigate import Investigation

class TestInvestigate(unittest.TestCase):
    def test_store_single_response(self):
        question = '你喜欢哪种编程语言？'
        my_investigate = Investigation(question)
        my_investigate.store_new_response('Python')
        self.assertIn('Python', my_investigate.responses)

if __name__ == '__main__':
    unittest.main()
# Ran 1 test in 0.002s
# OK

investigate_test.py（针对多个回答做测试）

import unittest
from investigate import Investigation

class TestInvestigate(unittest.TestCase):
    def test_store_single_response(self):
        question = '你喜欢那种编程语言？'
        my_investigate = Investigation(question)
        my_investigate.store_new_response('Python')
        self.assertIn('Python', my_investigate.responses)

    def test_store_three_responses(self):
        question = '你喜欢哪些编程语言？'
        my_investigate = Investigation(question)
        responses = ['C', 'Java', 'Python']
        for response in responses:
            my_investigate.store_new_response(response)
        for response in responses:
            self.assertIn(response, my_investigate.responses)

if __name__ == '__main__':
    unittest.main()
# Ran 2 tests in 0.002s
# OK

2.4. setUp方法

注意：

• unittest.TestCase类包含setUp方法，这样我们只需创建一次对象，并在各个测试方法中使用它。

• Python会先运行setUp方法，再运行以test_打头的方法，因此我们编写的每个测试方法就都可以使用在setUp中创建的对象了。

import unittest
from investigate import Investigation

class TestInvestigate(unittest.TestCase):
    def setUp(self):
        question = '你喜欢什么编程语言？'
        self.investigate = Investigation(question)
        self.responses = ['C', 'Python', 'Java']

    def test_store_single_response(self):
        self.investigate.store_new_response(self.responses[1])
        self.assertIn(self.responses[1], self.investigate.responses)

    def test_store_three_responses(self):
        for response in self.responses:
            self.investigate.store_new_response(response)
        for response in self.responses:
            self.assertIn(response, self.investigate.responses)

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

# Ran 2 tests in 0.002s
# OK