The third edition of this trusted guide demonstrates the practical advantages of test-driven development (TDD) with Python and describes how to develop a real web application. You'll learn how to write and run tests before building each part of your app and then develop the minimum amount of code required to pass those tests. The result? Clean code that works. In the process, author Harry Percival teaches software and web developers the basics of Django, Selenium, Git, JavaScript, and Mock libraries, along with current web development techniques. This book-updated for Python 3.14 and Django 4-clearly demonstrates how TDD encourages simple designs and inspires confidence. Fully updated, this third edition addresses:The TDD workflow, including the unit test/code cycle and refactoringUnit tests for classes and functions and functional tests for user interactions within the browserMock objects and the pros and cons of isolated versus integrated testsTesting and automation of deployments with a staging serverTests applied to the third-party plug-ins you integrate into your siteAutomatic tests using a continuous integration environmentUsing TDD to build a REST API with a JavaScript frontend interface