Authentication-Results instead of Received-SPF

No, but there is a similar application, pypolicyd-spf-python when does support that.

I noticed pypolicyd-spf-python supported that header, but I'd really rather not switch back, as the last time I used that policy daemon, it would break every time there was an update to python.
Is it possible that support for the Authentication-Results header will be added in a future version?

Not unless someone provides patches. I'd be interested to understand your problems with the Python implementation, since I'm the primary developer for it too.

My issues with pypolicyd-spf mainly revolved around it breaking whenever I updated python. At first, when I updated python, the SPF library broke and if memory serves I didn't resolve it until I reinstalled every related library or dependency. Then another update brought Python's SPF library to 3.x, which broke compatibility with pypolicyd-spf. I haven't had a problem with the Perl version, which is why I asked if it was possible to add Authentication-Results support in a future versin

Pypolicyd-spf 1.0 is functionally identical to 1.1, but uses python instead of python3 if you prefer that.

What O/S or distribution are you using that has problems like that? On Debian or derived distros (such as Ubuntu) the system takes care of those kinds of things for you.

I'm using Gentoo. I was using the gentoo package for pypolicyd-spf though, which at time of writing is version 0.8.1 - I never tried manually installing pypolicyd-spf as I thought Gentoo had the most up-to-date package already.

Thanks Scott Kitterman, that solved my question.