how to using python to unit test

Python has a built-in module called `unittest` that provides a framework for organizing and running unit tests. Here are the steps to create unit tests in Python using `unittest`:

1. Import the `unittest` module: `import unittest`
2. Create a test class that inherits from `unittest.TestCase`:

class TestMyProgram(unittest.TestCase):
    def test_function_one(self):
        # Test code goes here
        pass

    def test_function_two(self):
        # Test code goes here
        pass

3. Write test methods for each function you want to test. Each method should start with `test_` and contain assertions that validate the expected behavior of the function.
4. Run the tests using the `unittest.main()` method or by running the test file from the command line:

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

Here's an example of a test method that tests a function that adds two numbers:

def test_addition(self):
    result = add_numbers(2, 3)
    self.assertEqual(result, 5)

In this example, the `assertEqual` method is used to validate that the result of `add_numbers(2, 3)` is equal to 5. If the test fails, an error message will be displayed indicating which assertion failed.

Overall, the `unittest` module provides a simple and powerful way to write and run unit tests in Python.