code: def _grid_out_property(field_name, docstring):
      
      def getter(self):
          self._ensure_file()
  
          # Protect against PHP-237
          if field_name == 'length':
              return self._file.get(field_name, 0)
          return self._file.get(field_name, None)
  
      docstring += "\n\nThis attribute is read-only."
      return property(getter, doc=docstring)
docs: Create a GridOut property.