model.atom_range() -- return a subset of all atoms

atom_range(start, end)

This returns a list of a subset of atoms from the model, from start to end inclusive. Both start and end must be valid atom indices (see model.atoms). For example, if 'm' is a model object, 'm.atom_range('CA:1', 'CB:10')' returns a list of all atoms from the 'CA' atom in residue '1' to the 'CB' atom in residue '10', inclusive. This sublist can be accessed in just the same way as model.atoms.