code: def update_experiments(self):
          
          # 693 Remove if 'not applicable'
          for field in record_get_field_instances(self.record, '693'):
              subs = field_get_subfields(field)
              all_subs = subs.get('a', []) + subs.get('e', [])
              if 'not applicable' in [x.lower() for x in all_subs]:
                  record_delete_field(self.record, '693',
                                      field_position_global=field[4])
              new_subs = []
              experiment_a = ""
              experiment_e = ""
              for (key, value) in subs.iteritems():
                  if key == 'a':
                      experiment_a = value[0]
                      new_subs.append((key, value[0]))
                  elif key == 'e':
                      experiment_e = value[0]
              experiment = "%s---%s" % (experiment_a.replace(" ", "-"),
                                        experiment_e)
              translated_experiments = self.get_config_item(experiment,
                                                            "experiments")
              new_subs.append(("e", translated_experiments))
              record_delete_field(self.record, tag="693",
                                  field_position_global=field[4])
              record_add_field(self.record, "693", subfields=new_subs)
docs: Experiment mapping.