17.3 Why Use Package Imports?

If you're new to Python, make sure that you've mastered simple modules before stepping up to packages, as they are a somewhat advanced feature of Python. They do serve useful roles, especially in larger programs: they make imports more informative, serve as an organizational tool, simplify your module search path, and can resolve ambiguities.

First of all, because package imports give some directory information in program files, they both make it easier to locate your files, and serve as an organizational tool. Without package paths, you must resort to consulting the module search to find files more often. Moreover, if you organize your files into subdirectories for functional areas, package imports make it more obvious what role a module plays, and so make your code more readable. For example, a normal import of a file in a directory somewhere on the module search path:

import utilities

bears much less information than an import that includes path information:

import database.client.utilities

Package imports can also greatly simply your PYTHONPATH or .pth file search path settings. In fact, if you use package imports for all your cross-directory imports, and you make those package imports relative to a common root directory where all your Python code is stored, you really only need a single entry on your search path: the common root.