I have taken a few months worth of photos, imported them into Lightroom so that all the photos of a given day are in a folder, and edited a small fraction of the photos. My drive is filling up, so I would like to delete (I have backed them up) all the photos I didn't edit. Is there a way to do this in bulk? I could open each folder in Lightroom and delete the ones in the Library that are not edited, but it would be easier if the software will find the unedited ones and save me from opening each folder.
Not sure if this is an option you have already tried or not, but this might help speed things up for you.
In the Library module, choose the "Attribute" filter option from the filter bar across the top, and you can choose the "unedited photo" filter ... that will then show all the unedited photos in that folder. Once you've got them all in one view like that, you can do a mass selection and delete them all at once.