Software testing fundamentally highlights the importance of unit testing and conclusion of development with user based acceptance test suite to allow technical and non-technical to validate system completion. The project will introduce in Python 3 the tools to adapt two models used in software development TDD and BDD. Highlighting the importance in adapting behavior-driven testing and asynchronous scenarios exploring faulty behaviors introduced by applying multithreading in Python applications, the project concluded with an asynchronous python library and solutions of common multithreading faulty behaviors.