Book Image

Metaprogramming with Python

By : Sulekha AloorRavi
Book Image

Metaprogramming with Python

By: Sulekha AloorRavi

Overview of this book

Effective and reusable code makes your application development process seamless and easily maintainable. With Python, you will have access to advanced metaprogramming features that you can use to build high-performing applications. The book starts by introducing you to the need and applications of metaprogramming, before navigating the fundamentals of object-oriented programming. Next, you will learn about simple decorators, work with metaclasses, and later focus on introspection and reflection. You’ll also delve into generics and typing before defining templates for algorithms. As you progress, you will understand your code using abstract syntax trees and explore method resolution order. This Python book also shows you how to create your own dynamic objects before structuring the objects through design patterns. Finally, you will learn simple code-generation techniques along with discovering best practices and eventually building your own applications. By the end of this learning journey, you’ll have acquired the skills and confidence you need to design and build reusable high-performing applications that can solve real-world problems.
Table of Contents (21 chapters)
1
Part 1: Fundamentals – Introduction to Object-Oriented Python and Metaprogramming
4
Part 2: Deep Dive – Building Blocks of Metaprogramming I
11
Part 3: Deep Dive – Building Blocks of Metaprogramming II

Switching metaclasses

We can now look into the concept of switching metaclasses for a class. You may think, why do we need to switch metaclasses? Switching metaclasses reinforces the reusability concept of metaprogramming and in this case, it helps in understanding how a metaclass created for use on one class can also be used for a different class without impacting the class definition.

In the example for this section, we will be creating two meta classes – IncomeStatementMetaClass and BalanceSheetMetaClass. For the Malibu branch of ABC Megamart, we will create a class to capture the information required for its financial statements. The two financial statements relevant for this example are Income Statement attributes and Balance Sheet attributes for the Malibu branch. To differentiate where a particular attribute or method of a class should go, we will be creating two metaclasses that look at the names of the attributes and tag them under Income Statement or Balance Sheet...