#### Overview of this book

Choosing the right data structure is pivotal to optimizing the performance and scalability of applications. This new edition of Hands-On Data Structures and Algorithms with Python will expand your understanding of key structures, including stacks, queues, and lists, and also show you how to apply priority queues and heaps in applications. You’ll learn how to analyze and compare Python algorithms, and understand which algorithms should be used for a problem based on running time and computational complexity. You will also become confident organizing your code in a manageable, consistent, and scalable way, which will boost your productivity as a Python developer. By the end of this Python book, you’ll be able to manipulate the most important data structures and algorithms to more efficiently store, organize, and access data in your applications.
Preface
Free Chapter
Python Data Types and Structures
Introduction to Algorithm Design
Algorithm Design Techniques and Strategies
Stacks and Queues
Trees
Heaps and Priority Queues
Hash Tables
Graphs and Algorithms
Searching
Sorting
Selection Algorithms
String Matching Algorithms
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Index

A linked list (also called a singly linked list) contains a number of nodes in which each node contains data and a pointer that links to the next node. The link of the last node in the list is `None`, which indicates the end of the list. Refer to the following linked list in Figure 4.6, in which a sequence of integers is stored.

Figure 4.6: An example of a singly linked list

Next, we discuss how to create a singly linked list, and how to traverse it.

## Creating and traversing

In order to implement the singly linked list, we can use the node class that we created in the previous section. For example, we create three nodes, `n1`, `n2`, and `n3`, that store three strings:

``````n1 = Node('eggs')
n2 = Node('ham')
n3 = Node('spam')
``````

Next, we link the nodes sequentially to form the linked list. For example, in the following code, node `n1` is pointing to node `n2`, node `n2` is pointing to node `n3`, and node `n3` is the last node, and...