Python习题——2018-04-09作业

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的字符串，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

def city_country(city, country):
    city_country_name = city + ', ' + country
    return city_country_name.title()

test_cities.py

import unittest
from city_functions import city_country

class TestCityCountry(unittest.TestCase):
    def test_city_country(self):
        city_country_name = city_country('santiago', 'chile')
        self.assertEqual(city_country_name, 'Santiago, Chile')

unittest.main()

输出：

.
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK

　
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。

city_functions.py

def city_country(city, country, population):
    city_country_name = city + ', ' + country + ' - '
    city_country_name = city_country_name.title() + 'population '
    city_country_name = city_country_name + str(population)
    return city_country_name

输出：

E
======================================================================
ERROR: test_city_country (__main__.TestCityCountry)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_cities.py", line 7, in test_city_country
    city_country_name = city_country('santiago', 'chile')
TypeError: city_country() missing 1 required positional argument: 'population'

----------------------------------------------------------------------
Ran 1 test in 0.000s

FAILED (errors=1)

修改上述函数，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。

city_functions.py

def city_country(city, country, population = ''):
    if population:
        city_country_name = city + ', ' + country + ' - '
        city_country_name = city_country_name.title() + 'population '
        city_country_name = city_country_name + str(population)
    else:
        city_country_name = city + ', ' + country
        city_country_name = city_country_name.title()
    return city_country_name

输出：

.
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK

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。

test_cities.py

import unittest
from city_functions import city_country


class TestCityCountry(unittest.TestCase):
    def test_city_country(self):
        city_country_name = city_country('santiago', 'chile')
        self.assertEqual(city_country_name, 'Santiago, Chile')

    def test_city_country_population(self):
        city_country_population = city_country('santiago', 'chile', 5000000)
        correct_name = 'Santiago, Chile - population 5000000'
        self.assertEqual(city_country_population, correct_name)


unittest.main()

输出：

..
----------------------------------------------------------------------
Ran 2 tests in 0.000s

OK

　
11-3 雇员：编写一个名为Employee的类，其方法__init__()接受名、姓和年薪，并将它们都存储在属性中。编写一个名为give_raise()的方法，它默认将年薪增加5000美元，但也能够接受其他的年薪增加量。

为Employee编写一个测试用例，其中包含两个测试方法：test_give_default_raise()和test_give_custom_raise()。使用方法setUp()，以免在每个测试方法中都创建新的雇员实例。运行这个测试用例，确认两个测试都通过了。

employee.py

class Employee():
    def __init__(self, first_name, last_name, annual_salary):
        self.first_name = first_name
        self.last_name = last_name
        self.annual_salary = annual_salary

    def give_raise(self, money = 5000):
        self.annual_salary += money

test_employee.py

import unittest
from employee import Employee


class TestEmployee(unittest.TestCase):
    def setUp(self):
        self.my_employee = Employee('Hello', 'World', 66666)

    def test_give_default_raise(self):
        self.assertEqual(self.my_employee.first_name, 'Hello')
        self.assertEqual(self.my_employee.last_name, 'World')
        self.assertEqual(self.my_employee.annual_salary, 66666)

    def test_give_custom_raise(self):
        self.my_employee.give_raise(23333)
        self.assertEqual(self.my_employee.annual_salary, 89999)


unittest.main()

输出：

..
----------------------------------------------------------------------
Ran 2 tests in 0.000s

OK