11-1 城市和国家 ：编写一个函数，它接受两个形参：一个城市名和一个国家名。这个函数返回一个格式为City, Country 的字串，如Santiago, Chile 。将这个函数存储在一个名为city_functions.py的模块中。创建一个名为test_cities.py的程序，对刚编写的函数进行测试（别忘了，你需要导入模块unittest 以及要测试的函数）。编写一个名为test_city_country() 的方法，核实使用类似于'santiago' 和'chile' 这样的值来调用前述函数时，得到的字符串是正确的。运行test_cities.py ，确认测试test_city_country() 通过了。
city_functions.py
# -*- coding: utf-8 -*-
def get_city_country(city,country):
"""以一定的格式显示城市名和国家名"""
name = city + ", " + country
return name.title()
test_cities.py
# -*- coding: utf-8 -*-
import unittest
from city_functions import get_city_country
class CitiesTestCase(unittest.TestCase):
"""测试city_functions"""
def test_city_country(self):
"""能否正确处理像Santiago, Chile的城市名和国家名？"""
formatted_name = get_city_country("santiago","chile")
self.assertEqual(formatted_name,"Santiago, Chile")
unittest.main()
测试结果：
.
----------------------------------------------------------------------
Ran 1 test in 0.000s
OK
Process finished with exit code 0
11-2 人口数量 ：修改前面的函数，使其包含第三个必不可少的形参population ，并返回一个格式为City, Country - population xxx 的字符串，如Santiago, Chile - population 5000000 。运行test_cities.py，确认测试test_city_country() 未通过。
修改city_functions.py
# -*- coding: utf-8 -*-
def get_city_country(city,country,population):
"""以一定的格式显示城市名和国家名"""
name = city + ", " + country + " - " + population
return name.title()
测试结果：
E
======================================================================
ERROR: test_city_country (__main__.CitiesTestCase)
能否正确处理像Santiago, Chile的城市名和国家名？
----------------------------------------------------------------------
Traceback (most recent call last):
File "D:/Python/python_work/test/test_ciyies.py", line 10, in test_city_country
formatted_name = get_city_country("santiago","chile")
TypeError: get_city_country() takes exactly 3 arguments (2 given)
----------------------------------------------------------------------
Ran 1 test in 0.001s
FAILED (errors=1)
Process finished with exit code 1
修改上述函数get_city_country，将形参population 设置为可选的。再次运行test_cities.py，确认测试test_city_country() 又通过了。
再次修改city_functions.py
# -*- coding: utf-8 -*-
def get_city_country(city,country,population = ""):
"""以一定的格式显示城市名和国家名"""
if population:
name = city + ", " + country + " - " + population
else:
name = city + ", " + country
return name.title()
测试结果：
.
----------------------------------------------------------------------
Ran 1 test in 0.000s
OK
Process finished with exit code 0
再编写一个名为test_city_country_population() 的测试，核实可以使用类似于'santiago' 、'chile' 和'population=5000000' 这样的值来调用这个函数。再次运行test_cities.py，确认测试test_city_country_population() 通过了。我们在CitiesTestCase 类中再添加一个方法：
# -*- coding: utf-8 -*-
import unittest
from city_functions import get_city_country
class CitiesTestCase(unittest.TestCase):
"""测试city_functions"""
def test_city_country(self):
"""能否正确处理像Santiago, Chile的城市名和国家名？"""
formatted_name = get_city_country("santiago","chile")
self.assertEqual(formatted_name,"Santiago, Chile")
def test_city_country_population(self):
"""能否正确处理像Santiago, Chile - 5000000？"""
formatted_name = get_city_country("santiago","chile","5000000")
self.assertEqual(formatted_name,"Santiago, Chile - 5000000")
unittest.main()
测试结果：
..
----------------------------------------------------------------------
Ran 2 tests in 0.000s
OK
Process finished with exit code 0
在上面的测试代码中，输入数字5000000需要以字符串形式输入"5000000",所以我把代码改一下，可以直接输入数字5000000
city_functions.py
# -*- coding: utf-8 -*-
def get_city_country(city,country,population = ""):
"""以一定的格式显示城市名和国家名"""
if population:
name = city + ", " + country + " - " + str(population)
else:
name = city + ", " + country
return name.title()
test_cities.py
# -*- coding: utf-8 -*-
import unittest
from city_functions import get_city_country
class CitiesTestCase(unittest.TestCase):
"""测试city_functions"""
def test_city_country(self):
"""能否正确处理像Santiago, Chile的城市名和国家名？"""
formatted_name = get_city_country("santiago","chile")
self.assertEqual(formatted_name,"Santiago, Chile")
def test_city_country_population(self):
"""能否正确处理像Santiago, Chile - 5000000？"""
formatted_name = get_city_country("santiago","chile",5000000)
self.assertEqual(formatted_name,"Santiago, Chile - 5000000")
unittest.main()
测试结果：
..
----------------------------------------------------------------------
Ran 2 tests in 0.000s
OK
Process finished with exit code 0