1.20 Itse1359-1080-lists part 1

Table of contents

• Preface
  • Viewing tip
    • Figures
    • Listings
• Introduction
  • What you have learned
  • Introducing lists
• A subscription
  • Description
  • The primary
  • A clarification
  • The expression_list
  • Negative integers
    • Example of a negative index
    • More negative-integer rules
    • Good and bad negative integers
  • The character type
• A sequence
• A mapping
  • A real dictionary example
    • Is this a definition or a value?
    • No mention of the Python language
  • What about the expression_list?
• Slicing
• A mutable sequence
• A list
• Some sample programs
  • Creating, indexing, and slicing lists
    • An example list
      • Print an item using a subscription
      • Print some slices
      • Program output
    • Visualize sliced lists
      • Create new lists by slicing an existing list
      • Change an item in the original list
    • Lists can be concatenated
      • A concatenation program
      • Concatenation program output
    • Visualize concatenated lists
      • Create a new list by concatenating two existing lists
      • Change an element in an original list
    • Lists are mutable
      • Replace a string with another string
      • Multiply an integer element by two
      • Replace a string by a float
      • List modification program output
  • More to come
• Miscellaneous

Preface

This module is one in a collection of modules on Python designed for teaching ITSE 1359 Introduction to Scripting Languages: Python at Austin Community College in Austin, TX. It extends our Python knowledge to a new type of datacalled a list. This type of data, along with a string , is referred to as a sequence .

Viewing tip

I recommend that you open another copy of this module in a separate browser window and use the following links to easily find and view the Figuresand Listings while you are reading about them.

(Note to blind and visually impaired students: many of the Figures and all of the Listings inthis module are presented in plain text format and should be accessible using an audio screen reader or a braille display.)

Figures

• Figure 1 . Program output.
• Figure 2 . Visualize sliced lists.
• Figure 3 . Change an item in the original list.
• Figure 4 . Concatenation program output.
• Figure 5 . Visualize concatenated lists.
• Figure 6 . Change an element in an original list.
• Figure 7 . List modification program output.

Listings

• Listing 1 . A string as a primary.
• Listing 2 . Example of a negative index.
• Listing 3 . Good and bad negative integers.
• Listing 4 . An example list.
• Listing 5 . Lists can be concatenated.
• Listing 6 . Lists are mutable.

Introduction

What you have learned

In an earlier module you learned how to index and slice strings.

Introducing lists

In this module, we will extend that knowledge to a new type of data called a list . This type of data, along with a string , is referred to as a sequence .

First, however, I will nail down some terminology from the Python Language Reference , The Python Tutorial -- 3.1.3. Lists , and The Python Standard Library -- 4.6. Sequence Types -- list, tuple, range .

A subscription

I referred to a subscription as an index in the earlier module titled Itse1359-1070-Strings Part 2 in this book .