PyUnit

PyUnit is a unit testing framework for the Python programming language, modeled after the xUnit family of testing tools and inspired by JUnit. It provides a structured, repeatable approach to writing and running tests for Python code and is historically the precursor to Python's standard library unittest.

PyUnit introduces core concepts such as TestCase, which holds individual tests as methods; setUp and tearDown methods that run before and after each test; and TestSuite to group tests. It includes a variety of assertion helpers (for example, assertEqual, assertTrue, assertRaises) to verify expected behavior. Tests can be organized into fixtures, collected into test suites, and run by a test runner, with TextTestRunner being a common console-based runner. PyUnit supports skipping tests, expected failures, and subtests, enabling fine-grained test control and reporting.

In the Python ecosystem, PyUnit was effectively superseded by the unittest module in the Python standard library, which reimplements the PyUnit API and adds additional features, such as test discovery and more flexible runners. Today, the term PyUnit is mainly historical, but it remains referenced in discussions of Python testing history and as a port of JUnit concepts to Python.

The unittest module's API and design have been widely adopted in third-party tools and guides, and PyUnit’s influence is still acknowledged in documentation that describes analogous xUnit-style frameworks.

See also: unittest (Python's standard library).