Unit Testing in Python

I want to do automated unit testing for my class that I had written in Python.
To do automated unit testing I need three items:
1. The class I want to test.
2. The unit testing class.
3. The test runner.

Step 1:
-------
I created my class and named it as controllerTesting.py.
I added functions inside the file as below:


class Test():
    def returnZero(self):
        return 0
    
    def returnNonZero(self):
        return 12

    def returnSumNumber(self, number1, number2):
        return number1 + number2


Step 2:
-------
I created the file (test.py) and add the functions to test the functions in controllerTesting.py
I added code as below:


import unittest

from controllers.controllerTesting import Test

class TestControllerTest(unittest.TestCase):
    
    def testZeroReturn(self):
        val = 0
        t = Test()
        self.assertEqual(val, t.returnZero())
        
    def testNonZeroReturn(self):
        val = 0
        t = Test()
        self.assertNotEqual(val, t.returnNonZero())
        
    def testSumNumber(self):
        total = 4
        t = Test()
        r = t.returnSumNumber(2, 2)
        self.assertEqual(total, r, 'incorrect default size')



Step 3:
-------
I created the test runner (test_runner.py) and add these code to the file.


import unittest

from test import TestControllerTest

if __name__ == '__main__':
    suite = unittest.TestLoader().loadTestsFromTestCase(TestControllerTest)
    suite = unittest.TestSuite()
    suite.addTest(unittest.makeSuite(TestControllerTest))

    
    log_file = 'unit_testing_log.txt'
    f = open(log_file, "w")
    runner = unittest.TextTestRunner(f, verbosity=2).run(suite)    
    unittest.TextTestRunner(verbosity=2).run(suite)


Step 4:
-------
I Ran the unit test using the command.

python test_runner.py

The output of the testing were printed in unit_testing_log.txt located in the same directory of the unit testing file.

Output example:


testNonZeroReturn (test.TestControllerTest) ... ok
testSumNumber (test.TestControllerTest) ... FAIL
testZeroReturn (test.TestControllerTest) ... ok
testNonZeroReturn (test1.TestControllerTest2) ... ok
testSumNumber (test1.TestControllerTest2) ... ok
testZeroReturn (test1.TestControllerTest2) ... ok

======================================================================
FAIL: testSumNumber (test.TestControllerTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test.py", line 33, in testSumNumber
    self.assertEqual(total, r, 'incorrect default size')
AssertionError: 4 != 0 : incorrect default size

----------------------------------------------------------------------
Ran 6 tests in 0.001s

FAILED (failures=1)