Affiliated Packages

A major part of the Astropy Project is the concept of “Astropy affiliated packages”. An affiliated package is an astronomy-related Python package that is not part of the astropy core package, and is not managed by the project but is a part of the Astropy Project community. These packages demonstrate a commitment to Astropy’s goals of improving reuse, interoperability, and interface standards for Python astronomy and astrophysics packages. In many (but not all) cases, affiliated packages also follow similar development processes and package templates as for the core package.
If you are a developer interested in signing up as an affiliated package, details are in the Becoming an Affiliated Package section.
A related concept is that of “Astropy coordinated packages”. Coordinated packages are similar to affiliated packages, but the Astropy Project as a whole maintains them. In practice this means the Astropy coordination committee has administrative control of a coordinated package repository (delegated to the maintainers), and that maintainers of these packages have formal roles in the Astropy Project. The most prominent of these coordinated packages is the Astropy core package itself. In some cases these are packages identified by the core team as needing development separate from the core (either they are experimental or problem space-focused), while others started as affiliated packages but have become so important to the ecosystem that they grew to become coordinated.
One final related category are the “Astropy infrastructure packages”. These packages are those that are necessary infrastructure for Astropy packages - e.g. testing and documentation machinery. While occasionally these have astro-specific functionality, in general they are more generic packages that are useful to packages outside of astronomy, and as a result may have some maintainers outside the Astropy project. But some are also Astropy coordinated packages, with maintainers drawn from the infrastructure roles.
All packages should be available on PyPI. Some are available via conda, particularly through the conda-forge channel. That said, affiliated packages are developed independently of the Astropy core library. You should refer to the package’s documentation first if you encounter problems.
The following table lists all current Astropy coordinated packages.
Total number of coordinated packages:
The following table lists all currently registered affiliated packages.
NOTE: The listing is currently minimal because Astropy has just accepted APE 22 in January 2024. We are in the midst of transitioning to the new process in partnership with pyOpenSci, so we really appreciate your patience.
Total number of post-APE 22 affiliated packages:
All accepted pyOpenSci packages available here.
All currently under review packages via pyOpenSci available here.
This section contains the listing of Astropy Affiliated Packages that pre-dated APE 22. This section is frozen as of March 6, 2024.
Total number of pre-APE 22 affiliated packages:
Astropy uses the pyOpenSci peer review process to vet affiliated packages. If you are a developer of an astronomy package and would like your package to become affiliated with the Astropy Project, you submit your package directly to pyOpenSci. Astropy will be involved in the review, which will allow your package to become an affiliated package through that review process. You can also opt to be fast tracked through JOSS if desired. Read the pyOpenSci author guide to learn how to get started with submitting a package to pyOpenSci through their affiliated partner program Guidebook.
In addition to pyOpenSci criteria, we also apply Astropy-specific guidelines for reviewing affiliated packages. This will give you a sense of whether your package is ready for review. Broadly speaking, your package should:
Comply with general pyOpenSci review standards. Please see Peer Review Guide for Python Open Source Authors for more details.
Be potentially useful to astronomers. This can mean useful to a specific sub-domain of astronomy, or more broadly useful to a large fraction of astronomy (or beyond, as long as it is also useful for astronomy).
Specifically use, interface with, or provide complementary capabilities to other Astropy packages.
Use classes and functions from the astropy core package wherever possible and appropriate, and (as much as possible) avoid duplication with other packages in the Astropy ecosystem. This facilitates re-use of code and sharing of resources.
Be open to contributions from others. While this most straightforwardly means it follows a Github-based open development model (like the Astropy core package), alternative approaches are perfectly valid as long as they are consistent with basic principles of open source; e.g., an OSI-approved license.
Include instructions to users on how to cite your package. This is commonly done with a CITATION file. This file could include a Zenodo record (highly recommended), acknowledgement text, and/or journal article(s). Where possible, full BibTeX entries of these citations are recommended.
Include citations to other relevant papers and software following leading practices for citing astronomy software.
In addition, you should make an effort to connect with the Astropy developer community, including developers from the core astropy package or any related affiliated packages. If your package is determined to meet the above standards, it will be accepted and added to the affiliated package registry. Note however that if packages become unmaintained or do not meet the standards anymore, they may be removed from the list of affiliated packages, as per pyOpenSci policy.
If you are considering creating a new astronomy package and would like it to be an Astropy affiliated package, you can use the OpenAstronomy packaging guide to make it much easier to meet these standards. It reflects up-to-date Python packaging techniques to generate documentation like that used