How do you perform unit testing in Python? Have you used any testing frameworks before?

Unit testing involves testing individual units or components of code to ensure they work as expected. In Python, the unittest module provides a framework for writing and running tests. Popular third-party testing frameworks include pytest and nose. They simplify testing by offering features like automatic test discovery and more concise syntax. For instance, using pytest, you can write tests like:

def test_addition():
    assert 1 + 1 == 2

def test_subtraction():
    assert 5 - 3 == 2