14 best Python Unit Testing libraries in 2025

Unit testing is the first level of software testing where individual units/ components of a software are tested. The purpose is to validate that each unit of the software performs as designed. A unit is the smallest testable part of any software. It usually has one or a few inputs and usually a single output. Python Unit testing frameworks provide a solid base on which to build your test suite for any python codebase. Python Unit testing frameworks also help in automated testing, sharing test cases across multiple interfaces and monitoring code quality. Following are the best 14 best Python Unit Testing Open Source libraries including pynguin - PYthoN General UnIt Test geNerator is a testgeneration tool; unittest-xml-reporting - unit tes based test runner with Ant/JUnit like XML reporting; codepipeline-nested-cfn - CloudFormation templates, CodeBuild build specification & Python scripts to perform unit tests of a nested CloudFormation template.