code: def find_hba(self, all_atoms):
          
          data = namedtuple('hbondacceptor', 'a a_orig_atom a_orig_idx type')
          a_set = []
          for atom in filter(lambda at: at.OBAtom.IsHbondAcceptor(), all_atoms):
              if atom.atomicnum not in [9, 17, 35, 53] and atom.idx not in self.altconf:  # Exclude halogen atoms
                  a_orig_idx = self.Mapper.mapid(atom.idx, mtype=self.mtype, bsid=self.bsid)
                  a_orig_atom = self.Mapper.id_to_atom(a_orig_idx)
                  a_set.append(data(a=atom, a_orig_atom=a_orig_atom, a_orig_idx=a_orig_idx, type='regular'))
          return a_set
docs: Find all possible hydrogen bond acceptors