Distributing Python Modules
As a popular open source development project, Python has an active
supporting community of contributors and users that also make their software
available for other Python developers to use under open source license terms.
This allows Python users to share and collaborate effectively, benefiting
from the solutions others have already created to common (and sometimes
even rare!) problems, as well as potentially contributing their own
solutions to the common pool.
This guide covers the distribution part of the process. For a guide to
installing other Python projects, refer to the
installation guide.
Note
For corporate and other institutional users, be aware that many
organisations have their own policies around using and contributing to
open source software. Please take such policies into account when making
use of the distribution and installation tools provided with Python.
Key terms
- the Python Packaging Index is a public
repository of open source licensed packages made available for use by
other Python users
- the Python Packaging Authority are the group of
developers and documentation authors responsible for the maintenance and
evolution of the standard packaging tools and the associated metadata and
file format standards. They maintain a variety of tools, documentation
and issue trackers on both GitHub and
BitBucket.
distutils is the original build and distribution system first added
to the Python standard library in 1998. While direct use of distutils
is being phased out, it still laid the foundation for the current packaging
and distribution infrastructure, and it not only remains part of the
standard library, but its name lives on in other ways (such as the name
of the mailing list used to coordinate Python packaging standards
development).
- setuptools is a (largely) drop-in replacement for
distutils first
published in 2004. Its most notable addition over the unmodified
distutils tools was the ability to declare dependencies on other
packages. It is currently recommended as a more regularly updated
alternative to distutils that offers consistent support for more
recent packaging standards across a wide range of Python versions.
- wheel (in this context) is a project that adds the
bdist_wheel
command to distutils/setuptools. This produces a cross platform
binary packaging format (called “wheels” or “wheel files” and defined in
PEP 427) that allows Python libraries, even those including binary
extensions, to be installed on a system without needing to be built
locally.
Open source licensing and collaboration
In most parts of the world, software is automatically covered by copyright.
This means that other developers require explicit permission to copy, use,
modify and redistribute the software.
Open source licensing is a way of explicitly granting such permission in a
relatively consistent way, allowing developers to share and collaborate
efficiently by making common solutions to various problems freely available.
This leaves many developers free to spend more time focusing on the problems
that are relatively unique to their specific situation.
The distribution tools provided with Python are designed to make it
reasonably straightforward for developers to make their own contributions
back to that common pool of software if they choose to do so.
The same distribution tools can also be used to distribute software within
an organisation, regardless of whether that software is published as open
source software or not.
Reading the guide
The Python Packaging User Guide covers the various key steps and elements
involved in creating a project:
How do I…?
These are quick answers or links for some common tasks.
… choose a name for my project?
This isn’t an easy topic, but here are a few tips:
- check the Python Packaging Index to see if the name is already in use
- check popular hosting sites like GitHub, BitBucket, etc to see if there
is already a project with that name
- check what comes up in a web search for the name you’re considering
- avoid particularly common words, especially ones with multiple meanings,
as they can make it difficult for users to find your software when
searching for it
… create and distribute binary extensions?
This is actually quite a complex topic, with a variety of alternatives
available depending on exactly what you’re aiming to achieve. See the
Python Packaging User Guide for more information and recommendations.