Book Image

Python Data Structures and Algorithms

By : Benjamin Baka
Book Image

Python Data Structures and Algorithms

By: Benjamin Baka

Overview of this book

Data structures allow you to organize data in a particular way efficiently. They are critical to any problem, provide a complete solution, and act like reusable code. In this book, you will learn the essential Python data structures and the most common algorithms. With this easy-to-read book, you will be able to understand the power of linked lists, double linked lists, and circular linked lists. You will be able to create complex data structures such as graphs, stacks and queues. We will explore the application of binary searches and binary search trees. You will learn the common techniques and structures used in tasks such as preprocessing, modeling, and transforming data. We will also discuss how to organize your code in a manageable, consistent, and extendable way. The book will explore in detail sorting algorithms such as bubble sort, selection sort, insertion sort, and merge sort. By the end of the book, you will learn how to build components that are easy to understand, debug, and use in different applications.
Table of Contents (20 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
5
Stacks and Queues
7
Hashing and Symbol Tables

Nodes


At the heart of lists (and several other data structures) is the concept of a node. Before we go any further, let us consider this idea for a while.

To begin with, we shall create a few strings:

>>> a = "eggs"
>>> b = "ham"
>>> c = "spam"

Now you have three variables, each with a unique name, a type, and a value. What we do not have is a way of saying in which way the variables relate to each other. Nodes allow us to do this. A node is a container of data, together with one or more links to other nodes. A link is a pointer.

A simple type of node is one that only has a link to the next node.

Of course, knowing what we do about pointers, we realize that this is not entirely true. The string is not really stored in the node, but is rather a pointer to the actual string:

Thus the storage requirement for this simple node is two memory addresses. The data attribute of the nodes are pointers to the strings eggs and ham.