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

Using modules and packages with the Python interactive interpreter

As well as calling modules and packages from a Python script, it is often useful to call them directly from the Python interactive interpreter. This is a great way of employing the rapid application development (RAD) technique for Python programming: you make a change of some sort to a Python module or package and immediately see the results of your change by calling that module or package from the Python interactive interpreter.

There are, however, a few limitations and issues to be aware of. Let's take a closer look at how you can use the interactive interpreter to speed up your development of modules and packages; we'll also see where a different approach might suit you better.

Start by creating a new Python module named, and enter the following code into this file:

import re

def extract_numbers(s):
    pattern = r'[+-]?\d+(?:\.\d+)?'
    numbers = []
    for match in re.finditer(pattern, s):