Book Image

Modular Programming with Python

By : Erik Westra
Book Image

Modular Programming with Python

By: Erik Westra

Overview of this book

Python has evolved over the years and has become the primary choice of developers in various fields. The purpose of this book is to help readers develop readable, reliable, and maintainable programs in Python. Starting with an introduction to the concept of modules and packages, this book shows how you can use these building blocks to organize a complex program into logical parts and make sure those parts are working correctly together. Using clearly written, real-world examples, this book demonstrates how you can use modular techniques to build better programs. A number of common modular programming patterns are covered, including divide-and-conquer, abstraction, encapsulation, wrappers and extensibility. You will also learn how to test your modules and packages, how to prepare your code for sharing with other people, and how to publish your modules and packages on GitHub and the Python Package Index so that other people can use them. Finally, you will learn how to use modular design techniques to be a more effective programmer.
Table of Contents (16 chapters)
Modular Programming with Python
About the Author
About the Reviewer

Initializing a package

To initialize a package, you place the Python code inside the package's file. This code is then executed when the package is imported. For example, imagine that you have a package named test_package, which contains an file and one module named

You can place whatever code you like inside the file, and when the package (or a module within the package) is imported for the first time, that code will be executed.

You might be wondering why you might want to do this. Initializing a module makes sense as a module contains various functions that might need to be initialized before they are used (for example, by setting global variables to an initial value). But why initialize a package, rather than just a module within that package?

The answer lies in what happens when you import a package. When you do this, anything you define in the package's file becomes available at the package level. For example, imagine that...