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

Testing our reusable package

Now that we've written the code (or alternatively, downloaded it), let's take a look at how this package works. In a terminal window, set the current directory to the folder containing your quantities package directory, and type python to start the Python interpreter. Then, type the following:

>>> import quantities

If you haven't made any mistakes in typing in the source code, the interpreter should come back without any errors. If you have made any typos, you'll need to fix them before you can proceed.

Next, we have to initialize our quantities package by supplying the locale we want to use:

>>> quantities.init("international")

If you are in the United States, feel free to replace the value international with us so that you get localized spelling and units for your country.

Let's create a simple quantity, and then ask the Python interpreter to display it:

>>> q =, "km")
>>>> print(q)
24 kilometre

As you can...