code: def update_isbn(self):
          
          isbns = record_get_field_instances(self.record, '020')
          for field in isbns:
              for idx, (key, value) in enumerate(field[0]):
                  if key == 'a':
                      field[0][idx] = ('a', value.replace("-", "").strip())
docs: Remove dashes from ISBN.