The chapters in this part explore the elements of Python’s syntax and tooling that will enable you to write well-structured, documented, tested, and reproducible programs. I’ll show you how to solve 14 challenges from Rosalind.info. These problems are short and focused and allow for many different solutions that will help you explore Python. I’ll also teach you how to write a program, step-by-step, using tests to guide you and to let you know when you’re done. I encourage you to read the Rosalind page for each problem, as I do not have space to recapitulate all the background and information there.