Method _help_callback

python/python3/tornado/options.py:468–471

(self, value: bool)

        print(file=file)

    def _help_callback(self, value: bool) -> None:
        if value:
            self.print_help()
            sys.exit(0)

    def add_parse_callback(self, callback: Callable[[], None]) -> None:
        """Adds a parse callback, to be invoked when option parsing is done."""