Summary  
This chapter covers using Python’s built-in unittest framework to organize and run unit tests by defining TestCase subclasses, writing methods prefixed with test_ that use assertions like assertEqual, and automatically discovering and executing those tests to verify code behavior.

General domain of usage  
Software testing

Python's `unittest` framework is the standard way to write and run unit tests in Python. It helps you organize tests for your code, check that your functions and classes behave as expected, and catch bugs early. By using `unittest`, you can automate your testing process, making it easier to maintain and improve your Python projects. The framework is inspired by other xUnit frameworks and provides a familiar structure for writing test cases, grouping related tests, and reporting results.

Get a quick introduction to Python's `unittest` framework. See how to write your first test case, organize tests using classes, and use assertions to check your code's behavior. Learn why `unittest` is the standard tool for automated testing in Python projects and how it helps you catch bugs early and keep your code reliable.

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A typical `unittest` test case is a class that inherits from `unittest.TestCase`. Inside this class, you define methods that start with `test_`, each representing a specific scenario you want to check. These methods use special assertion methods like `assertEqual` to compare the actual output of your code with the expected result. This structure allows you to organize your tests logically, making them easy to read and maintain.

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The **`unittest`** framework is included in the Python standard library, so you do not need to install any additional packages to start testing your code.

Note

Which module is used for unit testing in Python's standard library?

Learn how to write reliable Python code by testing it the right way. This short course introduces unit testing using Python’s built-in unittest framework, focusing on practical skills rather than theory. You’ll learn what unit tests are, why they matter, and how to write clear, meaningful tests for real Python functions. The course covers assertions, testing edge cases, handling exceptions, and understanding test failures. You’ll also learn how to structure test files and run tests confidently.

Get started with the basics of unit testing in Python. Learn what unit tests are, why they are important, and how they fit into the software development process.

Learn how to write clear and meaningful unit tests using assertions and by testing a variety of scenarios.

Discover how to test code that raises exceptions and how to interpret test failures.

Learn how to structure your test files and run tests efficiently.

Getting Started with unittest