PyRTM contains functional python wrappers for SMARTS and SBdart, and is capable of modelling spectra in clear-sky and cloudy conditions. This would be a great set of functionality to incorporate into PVLIB. It could be a good project to either integrate the whole code base into the pvlib project (I was involved in the PyRTM project, and I think this would be great). Or, it might we worthwhile to pull in a set of functions to reference it in PVLIB, as PyRTM is already up on pip.

@uniphil any thoughts?