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

The application of metaclasses

In this section, we will look at an example where we will create a metaclass that can automatically modify the user-defined method attributes of any branch class that is newly created. To test this, let us follow these steps:

  1. Create a metaclass with the name BranchMetaclass:
    class BranchMetaclass(type):  
  2. Create a __new__ method with class instance, class name, base classes, and attributes as its arguments. In the __new__ method, import the inspect library, which can help inspect the input attributes:
        def __new__(classitself, classname, baseclasses, 
             attributes):  
            import inspect  
  3. Create a new dictionary, newattributes:
         newattributes = {}  

Iterate over the class attributes, check that the attributes...