Set proper log-level.

    :arg Optional[int, str] level: Level to be set. If None, use proper log
    level from command line option. Default value is ``logging.INFO``.

def set_loglevel(level: Union[int, str, None] = None) -> None:
    """Set proper log-level.

    :arg Optional[int, str] level: Level to be set. If None, use proper log
    level from command line option. Default value is ``logging.INFO``.
    """
    if level is not None:
        lv = level_to_int(level)
    elif config.logging:
        lv = level_to_int(config.logging)
    elif config.debug:
        lv = logging.DEBUG
    else:
        lv = logging.INFO
    root_logger.setLevel(lv)
    _log_handler.setLevel(lv)