piwheels
piwheels is Python package repository providing wheels (pre-built binaries) for the armv6 and armv7 architectures used by Raspberry Pi.
This repository contains the source code for building armv6 and armv7 wheels for packages found on PyPI, and the project's future will be discussed in GitHub issues. A very limited live repository is currently provided at piwheels.bennuttall.com, hosted on a Raspberry Pi 3. You shouldn't rely on this, as it's just for testing purposes at present, but feel free to try it out.
Why?
When you try to pip install a Python package which is implemented in C, it requires building for your computer's architecture. On a PC this will be x86 or x86_64. Some package maintainers provide wheels for these common architectures, which means you don't have to build the package yourself to install it. However, it's unlikely a package will provide an ARM wheel.
Some packages can take a long time to build, especially on BCM2835-based Raspberry Pi models (Pi 1 and Pi Zero). If a wheel is available (for your architecture), this makes it much easier to install, as pip simply downloads the wheel and installs it, no building required.
While Debian packages are available for some Python libraries, they are often older versions than available from PyPI, and if you're using a virtualenv, you need to pip install modules.
Who?
I'm Ben Nuttall, Raspberry Pi's Community Manager. I'm @ben_nuttall on Twitter.
How?
I have a Raspberry Pi 3 running the build script in this repository (written in Python), producing wheels and publishing them with a web server.
To manually build a wheel for a package, you simply run:
pip wheel <package>which (if successful) will produce a .whl file.
The format of the filename is: {python tag}-{abi tag}-{platform tag}. The platform tag for Raspberry Pi 1 and Zero (BCM2835) is armv6l, and for Pi 2 and 3 (BCM2836/BCM2837) is armv7l - although the Pi 3 has an ARMv8 CPU, the Raspbian OS runs in ARMv7 (32-bit) mode. Packages which do not require building will produce a wheel with a platform tag of any, and can be used on either architecture.
Usage
To install a package from piwheels, you supply the repository URL using the i or --index-url flag to the pip install command:
pip install <package> -i http://piwheels.bennuttall.com/or to use as an "extra" index:
pip install <package> --extra-index-url http://piwheels.bennuttall.com/Package maintainers
Package maintainers are able to upload wheels (from piwheels or built elsewhere) to their projects on PyPI, without needing to version-bump. It is not possible to replace existing files, but it is possible to upload additional files.
Developers
Developers wishing to work on this project should observe the following notes:
TODO
Contributing
Any help you can provide would be much appreciated! Please see the issue tracker to see where you can help.
Pull requests welcome - I'll try to write some project guidelines soon. It might be best to post an issue before starting work on a PR in case it's out of the scope of the project.
