#### 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
Other Books You May Enjoy
Index

# Hash Tables

A hash table is a data structure that implements an associative array in which the data is stored by mapping the keys to the values as `key-value` pairs. In many applications, we mostly require different operations such as insert, search, and delete in a dictionary data structure. For example, a symbol table is a data structure based on a hash table that is used by the compiler. A compiler that translates a programming language maintains a symbol table in which keys are character strings that are mapped to the identifiers. In such situations, a hash table is an effective data structure since we can directly compute the index of the required record by applying a hash function to the key. So, instead of using the key as an array index directly, the array index is computed by applying the hash function to the key. It makes it very fast to access an element from any index from the hash table. The hash table uses the hashing function to compute the index of where the data item...