Book Image

Software Architecture with Python

By : Anand Balachandran Pillai
Book Image

Software Architecture with Python

By: Anand Balachandran Pillai

Overview of this book

This book starts by explaining how Python fits into an application's architecture. As you move along, you will get to grips with architecturally significant demands and how to determine them. Later, you’ll gain a complete understanding of the different architectural quality requirements for building a product that satisfies business needs, such as maintainability/reusability, testability, scalability, performance, usability, and security. You will also use various techniques such as incorporating DevOps, continuous integration, and more to make your application robust. You will discover when and when not to use object orientation in your applications, and design scalable applications. The focus is on building the business logic based on the business process documentation, and understanding which frameworks to use and when to use them. The book also covers some important patterns that should be taken into account while solving design problems, as well as those in relatively new domains such as the Cloud. By the end of this book, you will have understood the ins and outs of Python so that you can make critical design decisions that not just live up to but also surpassyour clients’ expectations.
Table of Contents (18 chapters)
Software Architecture with Python
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Fundamentals of Modifiability – Cohesion & Coupling


Let us now get back to the main topic of modifiability, and discuss the two fundamental aspects that affect modifiability of code—namely, cohesion and coupling.

We've already discussed these concepts briefly in the first chapter. Let us do a quick review here.

The cohesion refers to how tightly the responsibilities of a module are related to each other. A module which performs a specific task or group of related tasks has high cohesion. A module in which a lot of functionality is dumped without a thought as to the core functionality would have low cohesion.

The coupling is the degree to which the functionality of two modules A and B are related. Two modules are strongly coupled if their functionality overlaps strongly at the code level—in terms of function or method calls. Any changes in module A would probably require changes in module B.

Strong coupling is always prohibitory for modifiability, as it increases the cost of maintaining...