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

Finding endpoints


We have created three nodes: one containing eggs, one ham, and another spam. The eggs node points to the ham node, which in turn points to the spam node. But what does the spam node point to? Since this is the last element in the list, we need to make sure its next member has a value that makes this clear.

If we make the last element point to nothing then we make this fact clear. In python, we will use the special value None to denote nothing:

The last node has its next point pointing to None. As such it is the last node in the chain of nodes.

Node

Here is a simple node implementation of what we have discussed so far:

    class Node: 
        def __init__(self, data=None): 
            self.data = data 
            self.next = None 

Note

Do not confuse the concept of a node with Node.js, a server-side technology implemented in JavaScript.

The next pointer is initialized to None, meaning that unless you change the value of next, the node is going to be an end-point. This is a good...