about 5.2

Software Metadata for Humans

Summary: define the metadata of your project in a single place, then make it available at setup-time and at runtime.

Let’s consider the about package as an example ; we add to our project files, in the source tree, a file named about.py that contains the metadata of the project:

about
|--- setup.py
|--- README.md
|...
|--- about
|    |--- __init__.py
|    |...
|    |--- about.py

This file contains the metadata (and a little boilerplate):

# coding: utf-8

metadata = dict(
  __name__        = "about",
  __version__     = "5.1.1",
  __license__     = "MIT License",
  __author__      = u"Sébastien Boisgérault <[e-mail]>",
  __url__         = "https://warehouse.python.org/project/about",
  __summary__     = "Software Metadata for Humans",
  __keywords__    = "Python / 2.7, OS independent, software development"
)

globals().update(metadata)

__all__ = metadata.keys()

Setup. To use this metadata, the setup.py file includes the code:

import about
import about.about

info = about.get_metadata(about.about)

# add extra information (contents, requirements, etc.).
info.update(...)

if __name__ == "__main__":
    setuptools.setup(**info)

Runtime. The metadata is stored as a collection of attributes of the about.about module. If we include in the about/__init__.py file the one-liner

from .about import *

they become available in the top-level module:

>>> import about
>>> print about.__name__
about
>>> print about.__version__
5.1.1
>>> print about.__license__
MIT License