Preface

This book uses the Python programming language to teach introductory computer science topics and a handful of useful applications. You’ll certainly learn a fair amount of Python as you work through this book, but along the way you’ll also learn about issues that every programmer needs to know: ways to approach a problem and break it down into parts, how and why to document your code, how to test your code to help ensure your program does what you want it to, and more.

We chose Python for several reasons:

• It is free and well documented. In fact, Python is one of the largest and best-organized open source projects going.

• It runs everywhere. The reference implementation, written in C, is used on everything from cell phones to supercomputers, and it’s supported by professional-quality installers for Windows, macOS, and Linux.

• It has a clean syntax. Yes, every language makes this claim, but during the several years that we have been using it at the University of Toronto, we have found that students make noticeably fewer “punctuation” mistakes with Python than with C-like languages.

• It is relevant. Thousands of companies use it every day: it is one of the languages used at Google, Industrial Light & Magic uses it extensively, and large portions of the game EVE Online are written in Python. It is also widely used by academic research groups.

• It is well supported by tools. Legacy editors like vi and Emacs all have Python editing modes, and several professional-quality IDEs are available. (We use IDLE, the free development environment that comes with a standard Python installation.)