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

An introduction to AntiPatterns


Software design principles represent a set of rules or guidelines that help software developers make design-level decisions. According to Robert Martin, there are four aspects of a bad design:

  • Immobile: An application is developed in such a way that it becomes very hard to reuse

  • Rigid: An application is developed in such a manner that any small change may in turn result in moving of too many parts of the software

  • Fragile: Any change in the current application results in breaking the existing system fairly easily

  • Viscose: Changes are done by the developer in the code or environment itself to avoid difficult architectural level changes

The above aspects of bad design, if applied, result in solutions that should not be implemented in the software architecture or development.

An AntiPattern is an outcome of a solution to recurring problems so that the outcome is ineffective and becomes counterproductive. What does this mean? Let's say that you come across a software...