I would like to rename a number of files in one operation, but it does not appear that pantheon-files supports this feature.
Pantheon-files does not currently support bulk renaming, however this feature is on the wishlist.
I'm currently on Pop!_Os and planning to move to elementary OS once Juno is released. I installed the beta release on another machine to test it from time to time. Bulk renaming is one of the features is miss the most.– woutAug 27, 2018 at 16:13
You could do that by integrating into Pantheon Files' context menu an option to use the bulk-rename tool of Thunar file manager, which has many other options than by just one rename-pattern.
sudo apt-get install thunar
gedit as text editor:
[Contractor Entry] Name=Rename file(s) in Thunar Icon=thunar MimeType=application/octet-stream Exec=thunar -B %U Gettext-Domain=pantheon-files