cmd.label('CAs', 'f"{oneletter}{resi}"') Cheers, Thomas On Fri, Jul 8, 2022 at 6:09 PM sunyeping via PyMOL-users <pymol-users@lists.sourceforge.net> wrote: > > Dear all, > > I want to label residues with the resn+resi, and I tried the following command > > one_letter ...