Class OptionParser

python/python3/tornado/options.py:133–496

A collection of options, a dictionary with object-like access. Normally accessed via static functions in the `tornado.options` module, which reference a global instance.

class OptionParser(object):
    """A collection of options, a dictionary with object-like access.

    Normally accessed via static functions in the `tornado.options` module,
    which reference a global instance.
    """

    def __init__(self) -> None:
        # we have to use self.__dict__ because we override setattr.
        self.__dict__["_options"] = {}
        self.__dict__["_parse_callbacks"] = []
        self.define(
            "help",
            type=bool,
            help="show this help information",
            callback=self._help_callback,
        )

    def _normalize_name(self, name: str) -> str:
        return name.replace("_", "-")

    def __getattr__(self, name: str) -> Any:
        name = self._normalize_name(name)
        if isinstance(self._options.get(name), _Option):
            return self._options[name].value()
        raise AttributeError("Unrecognized option %r" % name)

    def __setattr__(self, name: str, value: Any) -> None:
        name = self._normalize_name(name)
        if isinstance(self._options.get(name), _Option):
            return self._options[name].set(value)
        raise AttributeError("Unrecognized option %r" % name)

    def __iter__(self) -> Iterator:
        return (opt.name for opt in self._options.values())

    def __contains__(self, name: str) -> bool:
        name = self._normalize_name(name)
        return name in self._options

    def __getitem__(self, name: str) -> Any:
        return self.__getattr__(name)

    def __setitem__(self, name: str, value: Any) -> None:
        return self.__setattr__(name, value)

    def items(self) -> Iterable[Tuple[str, Any]]:
        """An iterable of (name, value) pairs.

        .. versionadded:: 3.1
        """
        return [(opt.name, opt.value()) for name, opt in self._options.items()]

    def groups(self) -> Set[str]:
        """The set of option-groups created by ``define``.

        .. versionadded:: 3.1
        """