log.py 文件源码

def enable_pretty_logging(options=None, logger=None):
    """Turns on formatted logging output as configured.

    This is called automatically by `tornado.options.parse_command_line`
    and `tornado.options.parse_config_file`.
    """
    if options is None:
        from tornado.options import options
    if options.logging is None or options.logging.lower() == 'none':
        return
    if logger is None:
        logger = logging.getLogger()
    logger.setLevel(getattr(logging, options.logging.upper()))
    if options.log_file_prefix:
        rotate_mode = options.log_rotate_mode
        if rotate_mode == 'size':
            channel = logging.handlers.RotatingFileHandler(
                filename=options.log_file_prefix,
                maxBytes=options.log_file_max_size,
                backupCount=options.log_file_num_backups)
        elif rotate_mode == 'time':
            channel = logging.handlers.TimedRotatingFileHandler(
                filename=options.log_file_prefix,
                when=options.log_rotate_when,
                interval=options.log_rotate_interval,
                backupCount=options.log_file_num_backups)
        else:
            error_message = 'The value of log_rotate_mode option should be ' +\
                            '"size" or "time", not "%s".' % rotate_mode
            raise ValueError(error_message)
        channel.setFormatter(LogFormatter(color=False))
        logger.addHandler(channel)

    if (options.log_to_stderr or
            (options.log_to_stderr is None and not logger.handlers)):
        # Set up color if we are in a tty and curses is installed
        channel = logging.StreamHandler()
        channel.setFormatter(LogFormatter())
        logger.addHandler(channel)