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

Deleting nodes


Another common operation that you would need to be able to do on a list is to delete nodes. This may seem simple, but we'd first have to decide how to select a node for deletion. Is it going to be by an index number or by the data the node contains? Here we will choose to delete a node by the data it contains.

The following is a figure of a special case considered when deleting a node from the list:

When we want to delete a node that is between two other nodes, all we have to do is make the previous node directly to the successor of its next node. That is, we simply cut the node to be deleted out of the chain as in the preceding image.

Here is the implementation of the delete() method may look like:

    def delete(self, data):
        current = self.tail
        prev = self.tail
        while current:
            if current.data == data:
                if current == self.tail:
                    self.tail = current.next
                else:
                    prev.next = current...