[chimerax-users] Getting number of residues from a PDB contain only a fragment

Hi, I used this Python code to get the number of residues: model = run(session, 'open %s' % input_model)[0] print(model.chains[0].num_residues) It works when the input_model is a complete pdb file. However, when the input_model only contain part of the structure of the full pdb but retains the full sequence information, the code above always return the num_residues of the full structure, not the input_model only. Is there any way to get this done? Best, Huy