app.py 文件源码

def log_to_stderr(level, formatter=_LOG_FORMATTER,
                  handler=logging.StreamHandler):
    """Setup logging or set logging level to STDERR.

    Args:
        level:  a logging level, like logging.INFO
        formatter: a logging.Formatter object
        handler:  logging.StreamHandler (this argument is for testing)
    """
    global _STDERR_HANDLER
    _level = get_loglevel(level)
    if type(_STDERR_HANDLER) is handler:
        _STDERR_HANDLER.setLevel(_level)
    else:
        _STDERR_HANDLER = handler(stream=sys.stderr)
        _STDERR_HANDLER.setLevel(_level)
        _STDERR_HANDLER.setFormatter(formatter)
        logging.getLogger('').addHandler(_STDERR_HANDLER)
    logging.debug('Setting logging at level=%s',
                 logging.getLevelName(_level))