From the Preface

This is the third edition of a book introducing you to one of the world’s most popular programming languages: Python. You may be a beginning programmer, or have some experience and want to add Python to the languages you already know. Throughout the book, I’ll sometimes contrast Python with other languages, to catch assumptions about how it works, especially with subtle differences.

Computing languages are easier to learn than human languages—they’re more concise and precise. Python is recognized as one of the easiest computing languages to learn, read, and write. It consists of data (like nouns in spoken languages), as well as instructions, or code (like verbs). In alternating chapters, you’ll be introduced to Python’s basic code and data structures, learn how to combine them, and build up to more advanced ones. The programs that you read and write will get longer and more complex.

You’ll learn the language and what to do with it. We’ll begin with the core Python language and its “batteries included” standard library, and advance to finding, downloading, installing, and using some good third-party packages. My emphasis is on whatever I’ve found useful in 20 years of production Python development, rather than fringe topics or complex hacks.

Although this is an introduction, some advanced topics are included because I want to expose you to them. Areas like databases and the web are still covered, but technology changes fast. A Python programmer might now be expected to know something about machine learning, queues, or Unicode. You’ll find details here on all of these.

Python has special features that work better than adapting styles from other languages you may know. For example, using for and iterators is a more direct way of making a loop than manually incrementing a counter variable.

When you’re learning new material, it’s hard to tell which terms are specific rather than colloquial, and which concepts are truly important. In other words, “Is this on the test?” I’ll highlight terms and ideas that have specific meaning or importance in Python, but not too many at once. Real Python code is included early and often.

Python isn’t perfect. I’ll show you features that seem odd or that should be avoided—and offer alternatives you can use instead.

Audience

Although prior programming experience may be helpful, I want to make it possible for beginning programmers to benefit from this book. Python is an excellent first computing language, and you don’t need to read and understand all of this book to get started.