Learning Python, 5th Edition

Chapter 7. String Fundamentals

So far, we’ve studied numbers and explored Python’s dynamic typing model. The next major type on our in-depth core object tour is the Python string—an ordered collection of characters used to store and represent text- and bytes-based information. We looked briefly at strings in Chapter 4. Here, we will revisit them in more depth, filling in some of the details we skipped earlier.

This Chapter’s Scope

Before we get started, I also want to clarify what we won’t be covering here. Chapter 4 briefly previewed Unicode strings and files—tools for dealing with non-ASCII text. Unicode is a key tool for some programmers, especially those who work in the Internet domain. It can pop up, for example, in web pages, email content and headers, FTP transfers, GUI APIs, directory tools, and HTML, XML and JSON text.

At the same time, Unicode can be a heavy topic for programmers just starting out, and many (or most) of the Python programmers I meet today still do their jobs in blissful ignorance of the entire topic. In light of that, this book relegates most of the Unicode story to Chapter 37 of its Advanced Topics part as optional reading, and focuses on string basics here.

That is, this chapter tells only part of the string story in Python—the part that most scripts use and most programmers need to know. It explores the fundamental str string type, which handles ASCII text, and works the same regardless of which version of Python you use. Despite this intentionally limited ...