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
About the Author
About the Reviewer

A UML class diagram for the MVC design pattern

Let's now understand more about the MVC pattern with the help of the following UML diagram.

As we discussed in the previous sections, the MVC pattern has the following main participants: the Model, View, and Controller class.

In the UML diagram, we can see three main classes in this pattern:

  • The Model class: This defines the business logic or operations attached to certain tasks from the client.

  • The View class: This defines the view or representation that is viewed by the client. The model presents the data to the view based on the business logic.

  • The Controller class: This is essentially an interface that is between the view and model. When the client takes certain actions, the controller directs the query from the view to model.

The following is a code example to understand the pattern with all the participants involved:

class Model(object):
    def logic(self):
        data = 'Got it!'
        print("Model: Crunching data as per business logic"...