code: def hydrophobic_atoms(self, all_atoms):
          
          atom_set = []
          data = namedtuple('hydrophobic', 'atom orig_atom orig_idx')
          atm = [a for a in all_atoms if a.atomicnum == 6 and set([natom.GetAtomicNum() for natom
                                                                   in pybel.ob.OBAtomAtomIter(a.OBAtom)]).issubset(
              {1, 6})]
          for atom in atm:
              orig_idx = self.Mapper.mapid(atom.idx, mtype=self.mtype, bsid=self.bsid)
              orig_atom = self.Mapper.id_to_atom(orig_idx)
              if atom.idx not in self.altconf:
                  atom_set.append(data(atom=atom, orig_atom=orig_atom, orig_idx=orig_idx))
          return atom_set
docs: Select all carbon atoms which have only carbons and/or hydrogens as direct neighbors.