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

Controlling what gets imported

When you import a module or package, or when you use a wildcard import such as from my_module import *, the Python interpreter loads the contents of the given module or package into your global namespace. If you are importing from a module, all of the top-level functions, constants, classes, and other definitions will be imported. When importing from a package, all of the top-level functions, constants, and so on defined in the package's file will be imported.

By default, these imports load everything from the given module or package. The only exception is that a wildcard import will automatically skip any function, constant, class, or other definition starting with an underscore—this has the effect of excluding private definitions from the wildcard import.

While this default behavior generally works well, there are times when you may want more control over what gets imported. To do this, you can use a special variable named __all__.

To see how the...