Expert Python Programming - Third Edition

PEP 420 - implicit namespace packages

If you use and target only Python 3, then there is good news for you. PEP 420 (Implicit Namespace Packages) introduced a new way to define namespace packages. It is part of the standards track and became an official part of the language since version 3.3. In short, every directory that contains Python packages or modules (including namespace packages too) is considered a namespace package if it does not contain the __init__.py file. So, the following are examples of file structures presented in the previous section:

$ tree acme.sql/acme.sql/├── acme│   └── sql│       └── __init__.py└── setup.py2 directories, 2 files$ tree acme.templating/acme.templating/├── acme│   └── templating│       └── __init__.py└── setup.py2 directories, ...