there are a couple of alternative (and eventually ObsPy will hopefully
ship with that capability) discussed here:
The sfile_util section of EQcorrscan might be useful, currently out doesn’t include focal mechanism information though. It is mentioned the pull request Lion sent you, and are hoping to include it in obspy soon. Before I include I plan on including the focal mechanism information though. You can install EQcorrscan via pip.
If you do use the EQcorrscan tool, could you let me know if there is anything else you would like to see in it? Working on it at the moment. All the functionality included is tested though.
Hope it helps,