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

Understanding polymorphism

Polymorphism is the concept of the OOP paradigm where we can reuse the name of a function from a parent class either by redefining or overriding an existing function or by creating two different functions for two different classes with the same name and using them separately. In this section, we will look at examples for both variations of polymorphism:

  • Polymorphism within inheritance
  • Polymorphism in independent classes

Polymorphism within inheritance

Let us look at the earlier example of the child class, NYC, which inherits from Branch. To calculate the selling price along with the local tax rate for the specific branch, we created a new method within the NYC class named calc_tax_nyc. Instead of creating a new method, we can also override the Parent method, calc_tax, with the new calculation in the child class. This concept is polymorphism within inheritance. Here is a representation of it:

Figure 2.9 –...