Book Image

Learning Python Design Patterns - Second Edition - Second Edition

By : Chetan Giridhar, Gennadiy Zlobin
Book Image

Learning Python Design Patterns - Second Edition - Second Edition

By: Chetan Giridhar, Gennadiy Zlobin

Overview of this book

With the increasing focus on optimized software architecture and design it is important that software architects think about optimizations in object creation, code structure, and interaction between objects at the architecture or design level. This makes sure that the cost of software maintenance is low and code can be easily reused or is adaptable to change. The key to this is reusability and low maintenance in design patterns. Building on the success of the previous edition, Learning Python Design Patterns, Second Edition will help you implement real-world scenarios with Python’s latest release, Python v3.5. We start by introducing design patterns from the Python perspective. As you progress through the book, you will learn about Singleton patterns, Factory patterns, and Façade patterns in detail. After this, we’ll look at how to control object access with proxy patterns. It also covers observer patterns, command patterns, and compound patterns. By the end of the book, you will have enhanced your professional abilities in software architecture, design, and development.
Table of Contents (19 chapters)
Learning Python Design Patterns Second Edition
Credits
Foreword
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

The Template Method pattern in the real world


Let's take a very easy-to-understand scenario to implement the Template method pattern. Imagine the case of a travel agency, say, Dev Travels. Now how do they typically work? They define various trips to various locations and come up with a holiday package for you. A package is essentially a trip that you, as a customer, undertakes. A trip has details such as the places visited, transportation used, and other factors that define the trip itinerary. This same trip can be customized differently based on the needs of the customers. This calls for the Template Method pattern, doesn't it?

Design Considerations:

  • For the preceding scenario, based on the UML diagram, we should create an AbstractClass interface that defines a trip

  • The trip should contain multiple abstract methods that define the transportation used, places visited on day1, day2, and day3, assuming that it's a three-day long weekend trip, and also define the return journey

  • The itinerary()...