092-Python Unit Test (2)

 

 

 

 

Today we're going to learn Lesson 2 of Python Unit Testing

Let's start with an example

 

class Employee:
    raise_amt = 1.05

    def __init__(self, first, last, pay):
        self.first = first
        self.last = last
        self.pay = pay

    @property
    def email(self):
        return '{}.{}@email.com'.format(self.first, self.last)

    @property
    def fullname(self):
        return '{} {}'.format(self.first, self.last)

    def apply_raise(self):
        self.pay = int(self.pay * self.raise_amt)

 

How to deal with the three methods in this example

1.email

2.fullname

3.apply_raise

For testing,

Simply, use the assert_you've learnedEqual is OK

 

 

 

Let's write out the test code

Note that the naming must be test_xxx.py

For example, if it isEmployee.pyThen the test file is test_employee.py

import unittest
from emp import Employee


class TestEmp(unittest.TestCase):

    def test_email(self):
        emp_1 = Employee('Bill', 'Gates', 1000)
        emp_2 = Employee('Steve', 'Jobs', 2000)
        self.assertEqual(emp_1.email, 'Bill.Gates@email.com')
        self.assertEqual(emp_2.email, 'Steve.Jobs@email.com')

    def test_fullname(self):
        emp_1 = Employee('Bill', 'Gates', 1000)
        emp_2 = Employee('Steve', 'Jobs', 2000)
        self.assertEqual(emp_1.fullname, 'Bill Gates')
        self.assertEqual(emp_2.fullname, 'Steve Jobs')

    def test_apply_raise(self):
        emp_1 = Employee('Bill', 'Gates', 1000)
        emp_2 = Employee('Steve', 'Jobs', 2000)
        emp_1.apply_raise()
        emp_2.apply_raise()
        self.assertEqual(emp_1.pay, 1050)
        self.assertEqual(emp_2.pay, 2100)

They are all tested using the assertEqual method

 

 

 

 

 

In this test code, we found that

In each test method, we wrote

emp_1 = Employee('Bill', 'Gates', 1000)
emp_2 = Employee('Steve', 'Jobs', 2000)

This is obviously redundant,

How do you reuse these two lines of code to create objects in each test method?

We need to use the setUp method

 

import unittest
from emp import Employee


class TestEmp(unittest.TestCase):

    def setUp(self):
        print('setUp')
        self.emp_1 = Employee('Bill', 'Gates', 1000)
        self.emp_2 = Employee('Steve', 'Jobs', 2000)

    def test_email(self):
        print('test_email')
        self.assertEqual(self.emp_1.email, 'Bill.Gates@email.com')
        self.assertEqual(self.emp_2.email, 'Steve.Jobs@email.com')

    def test_fullname(self):
        print('test_fullname')
        self.assertEqual(self.emp_1.fullname, 'Bill Gates')
        self.assertEqual(self.emp_2.fullname, 'Steve Jobs')

    def test_apply_raise(self):
        print('test_apply_raise')
        self.emp_1.apply_raise()
        self.emp_2.apply_raise()
        self.assertEqual(self.emp_1.pay, 1050)
        self.assertEqual(self.emp_2.pay, 2100)

As in the code above, we added the setUp method.

The setUp method is executed before each test method is executed.

So before each test method is executed, self is given two Employee s

 

 

Let's run the test code

setUp
test_apply_raise
setUp
test_email
setUp
test_fullname


Ran 3 tests in 0.004s

OK

We see that,

setUp first, then test method

 

 

 

 

 

 

The setUp method is executed before each test method.

In addition to setUp, there are tearDown methods

The tearDown method is executed after each test method.

In addition, there are setUpClass and tearDownClass methods, and the difference between them is

The class method is before and after the entire class

Let's look at the code

import unittest
from emp import Employee


class TestEmp(unittest.TestCase):

    @classmethod
    def setUpClass(cls):
        print('setUpClass')

    @classmethod
    def tearDownClass(cls):
        print('tearDownClass')

    def setUp(self):
        print('setUp')
        self.emp_1 = Employee('Bill', 'Gates', 1000)
        self.emp_2 = Employee('Steve', 'Jobs', 2000)

    def tearDown(self):
        print('tearDown')

    def test_email(self):
        print('test_email')
        self.assertEqual(self.emp_1.email, 'Bill.Gates@email.com')
        self.assertEqual(self.emp_2.email, 'Steve.Jobs@email.com')

    def test_fullname(self):
        print('test_fullname')
        self.assertEqual(self.emp_1.fullname, 'Bill Gates')
        self.assertEqual(self.emp_2.fullname, 'Steve Jobs')

    def test_apply_raise(self):
        print('test_apply_raise')
        self.emp_1.apply_raise()
        self.emp_2.apply_raise()
        self.assertEqual(self.emp_1.pay, 1050)
        self.assertEqual(self.emp_2.pay, 2100)

 

 

Look at the results

setUpClass
setUp
test_apply_raise
tearDown
setUp
test_email
tearDown
setUp
test_fullname
tearDown
tearDownClass


Ran 3 tests in 0.005s

OK

Thus, the class method begins and ends with

setUp and tearDown before and after