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

Exchanging decorators from one function to another

We now have an understanding of what a function decorator is and how a function decorator can be used for more than one function. We will look into further exploring the reusability concept of decorators by creating two different decorators to serve two different purposes and later utilizing them by interchanging the decorators between different functions.

To demonstrate this concept, we will be creating Decorator 1 for function 1 and Decorator 2 for function 2, and then we will be exchanging them from one function to another. Let us create two decorators to decorate two different functions.

Decorator 1 will be created to convert a date argument that is provided as a holiday date to the function that sets holidays for the Alabama branch of ABC Megamart.

The following figure is a representation of Decorator 1 and its Function 1.

Figure 3.2 – Date converter as a decorator

Let’s take a look...