code: def external_editor(self, filename, goto=-1):
          
          editor_path = CONF.get('internal_console', 'external_editor/path')
          goto_option = CONF.get('internal_console', 'external_editor/gotoline')
          try:
              args = [filename]
              if goto > 0 and goto_option:
                  args.append('%s%d'.format(goto_option, goto))
              programs.run_program(editor_path, args)
          except OSError:
              self.write_error("External editor was not found:"
                               " %s\n" % editor_path)
docs: Edit in an external editor
          Recommended: SciTE (e.g. to go to line where an error did occur)