queue.py 文件源码

def queuify_logger(logger, queue_handler, queue_listener):
    """Replace logger's handlers with a queue handler while adding existing
    handlers to a queue listener.

    This is useful when you want to use a default logging config but then
    optionally add a logger's handlers to a queue during runtime.

    Args:
        logger (mixed): Logger instance or string name of logger to queue-ify
            handlers.
        queue_handler (QueueHandler): Instance of a ``QueueHandler``.
        queue_listener (QueueListener): Instance of a ``QueueListener``.

    """
    if isinstance(logger, str):
        logger = logging.getLogger(logger)

    # Get handlers that aren't being listened for.
    handlers = [handler for handler in logger.handlers
                if handler not in queue_listener.handlers]

    if handlers:
        # The default QueueListener stores handlers as a tuple.
        queue_listener.handlers = \
            tuple(list(queue_listener.handlers) + handlers)

    # Remove logger's handlers and replace with single queue handler.
    del logger.handlers[:]
    logger.addHandler(queue_handler)