code: def tab_stop(editor, value):
      
      if value is None:
          editor.show_message('tabstop=%i' % editor.tabstop)
      else:
          try:
              value = int(value)
              if value > 0:
                  editor.tabstop = value
              else:
                  editor.show_message('Argument must be positive')
          except ValueError:
              editor.show_message('Number required after =')
docs: Set tabstop.