Expert Python Programming - Third Edition

Modules and packages

Besides the special module __init__, the module names are in lowercase. The following are some examples from the standard library:

• os
• sys
• shutil

The Python standard library does not use underscores for module names to separate words but they are used commonly in many other projects. When the module is private to the package, a leading underscore is added. Compiled C or C++ modules are usually named with an underscore and imported in pure Python modules. Package names follow the same rules, since they act more like structured modules.

Let's discuss the naming guide in the next section.