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

Creating a domain-specific data type

In this section, let’s create an even more customized data type to deal with the dress size of the fashion department of ABC Megamart. The DressSize data type we defined in the preceding section handles any integer as input and performs the operations we overloaded. When we look at the domain of the fashion industry and consider the dress size as a domain-specific variable, the DressSize data type should ideally be considering only specific values for size and not accept all integers. The dress size will be based on the size of dresses held in the inventory of ABC Megamart.

The accepted input for dress size in this example should be the list of integers, [36,38,40,42,44,46,48], or the list of strings that indicates the equivalent text values for dress size such as [XS,S,M,L,XL,XXL,XXXL]:

  1. Let’s begin by creating the DressSize class along with its methods to work as a domain-specific data type, and initialize size as its...