Book Image

Getting Started with Python

By : Fabrizio Romano, Benjamin Baka, Dusty Phillips
Book Image

Getting Started with Python

By: Fabrizio Romano, Benjamin Baka, Dusty Phillips

Overview of this book

This Learning Path helps you get comfortable with the world of Python. It starts with a thorough and practical introduction to Python. You’ll quickly start writing programs, building websites, and working with data by harnessing Python's renowned data science libraries. With the power of linked lists, binary searches, and sorting algorithms, you'll easily create complex data structures, such as graphs, stacks, and queues. After understanding cooperative inheritance, you'll expertly raise, handle, and manipulate exceptions. You will effortlessly integrate the object-oriented and not-so-object-oriented aspects of Python, and create maintainable applications using higher level design patterns. Once you’ve covered core topics, you’ll understand the joy of unit testing and just how easy it is to create unit tests. By the end of this Learning Path, you will have built components that are easy to understand, debug, and can be used across different applications. This Learning Path includes content from the following Packt products: • Learn Python Programming - Second Edition by Fabrizio Romano • Python Data Structures and Algorithms by Benjamin Baka • Python 3 Object-Oriented Programming by Dusty Phillips
Table of Contents (31 chapters)
Title Page
Copyright and Credits
About Packt
Stacks and Queues
Hashing and Symbol Tables


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.