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

Import gotchas

While modules and packages are extremely useful, there are times when Python's import machinery can leave you with subtle problems that can take a long time to figure out. In this section, we will discuss some of the more common problems that you are likely to encounter while working with modules and packages.

Using an existing name for your module or package

Imagine that you're writing a program that makes use of the Python Standard Library. For example, you might make use of the random module to do the following:

import random
print(random.choice(["yes", "no"]))

Your program is working correctly until you decide that it has too many mathematical functions in the main script, and you refactor it to move these functions into a separate module. You decide to call this module, and store it in your main program's directory. As soon as you do this, the previous code will crash with the following error:

Traceback (most recent call last):
  File "", line 5, in <module...