Chapter 6. Sequences: Strings, Lists, and Tuples

Chapter Topics

• Introduction to Sequences

• Strings

• Lists

• Tuples

The next family of Python types we will be exploring are those whose items are ordered sequentially and accessible via index offsets into its set of elements. This group, known as sequences, includes the following types: strings (regular and unicode), lists, and tuples.

We call these sequences because they are made up of sequences of "items" making up the entire data structure. For example, a string consists of a sequence of characters (even though Python does not have an explicit character type), so the first character of a string "Hello" is 'H', the second character is 'e', and so on. Likewise, lists and tuples are sequences of various Python objects.

We will first introduce all operators and built-in functions (BIFs) that apply to all sequences, then cover each type individually. For each sequence type, we will detail the following:

• Introduction

• Operators

• Built-in functions

• Built-in methods (if applicable)

• Special features (if applicable)

• Related modules (if applicable)

We will conclude this chapter with a reference chart that summarizes all of the operators and functions applicable to all sequences. Let us begin by taking a high-level overview.