This document is for Kombu's development version, which can be significantly different from previous releases. Get the stable docs here: 5.3.

# Carrot Compatibility - `kombu.compat`

Carrot compatibility interface.

See https://pypi.org/project/carrot/ for documentation.

## Publisher

Replace with `kombu.Producer`.

class kombu.compat.Publisher(connection, exchange=None, routing_key=None, exchange_type=None, durable=None, auto_delete=None, channel=None, **kwargs)

  Carrot compatible producer.

  auto_declare = True

    By default, if a default exchange is set, that exchange will be declare when publishing a message.

  auto_delete = False
  property backend
  property channel
  close()
  compression = None

    Default compression method. Disabled by default.

  property connection
  declare()

    Declare the exchange.

    ### Note:

    > This happens automatically at instantiation when the `auto_declare` flag is enabled.

  durable = True
  exchange = ''

    Default exchange

  exchange_type = 'direct'
  maybe_declare(entity, retry=False, **retry_policy)

    Declare exchange if not already declared during this session.

  on_return = None

    Basic return callback.

  publish(body, routing_key=None, delivery_mode=None, mandatory=False, immediate=False, priority=0, content_type=None, content_encoding=None, serializer=None, headers=None, compression=None, exchange=None, retry=False, retry_policy=None, declare=None, expiration=None, timeout=None, confirm_timeout=None, **properties)

    Publish message to the specified exchange.

    ### Arguments:

    > body (Any): Message body. routing_key (str): Message routing key. delivery_mode (enum): See `delivery_mode`. mandatory (bool): Currently not supported. immediate (bool): Currently not supported. priority (int): Message priority. A number between 0 and 9. content_type (str): Content type. Default is auto-detect. content_encoding (str): Content encoding. Default is auto-detect. serializer (str): Serializer to use. Default is auto-detect. compression (str): Compression method to use. Default is none. headers (Dict): Mapping of arbitrary headers to pass along

    > > with the message body.

    > exchange (kombu.entity.Exchange, str): Override the exchange.

    >   Note that this exchange must have been declared.

    > declare (Sequence[EntityT]): Optional list of required entities

    >   that must have been declared before publishing the message. The entities will be declared using `maybe_declare()`.

    > retry (bool): Retry publishing, or declaring entities if the

    >   connection is lost.

    > retry_policy (Dict): Retry configuration, this is the keywords

    >   supported by `ensure()`.

    > expiration (float): A TTL in seconds can be specified per message.

    >   Default is no expiration.

    > timeout (float): Set timeout to wait maximum timeout second

    >   for message to publish.

    > confirm_timeout (float): Set confirm timeout to wait maximum timeout second

    >   for message to confirm publishing if the channel is set to confirm publish mode.

    > **properties (Any): Additional message properties, see AMQP spec.

  release()
  revive(channel)

    Revive the producer after connection loss.

  routing_key = ''

    Default routing key.

  send(*args, **kwargs)
  serializer = None

    Default serializer to use. Default is JSON.

## Consumer

Replace with `kombu.Consumer`.

class kombu.compat.Consumer(connection, queue=None, exchange=None, routing_key=None, exchange_type=None, durable=None, exclusive=None, auto_delete=None, **kwargs)

  Carrot compatible consumer.

  exception ContentDisallowed

    Consumer does not allow this content-type.

    add_note(note, /)

      Add a note to the exception

    args
    with_traceback(tb, /)

      Set self.__traceback__ to tb and return self.

  accept = None

    List of accepted content-types.

    An exception will be raised if the consumer receives a message with an untrusted content type. By default all content-types are accepted, but not if `kombu.disable_untrusted_serializers()` was called, in which case only json is allowed.

  add_queue(queue)

    Add a queue to the list of queues to consume from.

    ### Note:

    > This will not start consuming from the queue, for that you will have to call `consume()` after.

  auto_declare = True

    By default all entities will be declared at instantiation, if you want to handle this manually you can set this to `False`.

  auto_delete = False
  callbacks = None

    List of callbacks called in order when a message is received.

    The signature of the callbacks must take two arguments: (body, message), which is the decoded message body and the `Message` instance.

  cancel()

    End all active queue consumers.

    ### Note:

    > This does not affect already delivered messages, but it does mean the server will not send any more messages for this consumer.

  cancel_by_queue(queue)

    Cancel consumer by queue name.

  channel = None

    The connection/channel to use for this consumer.

  close()

    End all active queue consumers.

    ### Note:

    > This does not affect already delivered messages, but it does mean the server will not send any more messages for this consumer.

  property connection
  consume(no_ack=None)

    Start consuming messages.

    Can be called multiple times, but note that while it will consume from new queues added since the last call, it will not cancel consuming from removed queues ( use `cancel_by_queue()`).

    ### Arguments:

    > no_ack (bool): See `no_ack`.

  consuming_from(queue)

    Return `True` if currently consuming from queue’.

  declare()

    Declare queues, exchanges and bindings.

    ### Note:

    > This is done automatically at instantiation when `auto_declare` is set.

  discard_all(filterfunc=None)
  durable = True
  exchange = ''
  exchange_type = 'direct'
  exclusive = False
  fetch(no_ack=None, enable_callbacks=False)
  flow(active)

    Enable/disable flow from peer.

    This is a simple flow-control mechanism that a peer can use to avoid overflowing its queues or otherwise finding itself receiving more messages than it can process.

    The peer that receives a request to stop sending content will finish sending the current content (if any), and then wait until flow is reactivated.

  iterconsume(limit=None, no_ack=None)
  iterqueue(limit=None, infinite=False)
  no_ack = None

    Flag for automatic message acknowledgment. If enabled the messages are automatically acknowledged by the broker. This can increase performance but means that you have no control of when the message is removed.

    Disabled by default.

  on_decode_error = None

    Callback called when a message can’t be decoded.

    The signature of the callback must take two arguments: (message, exc), which is the message that can’t be decoded and the exception that occurred while trying to decode it.

  on_message = None

    Optional function called whenever a message is received.

    When defined this function will be called instead of the `receive()` method, and `callbacks` will be disabled.

    So this can be used as an alternative to `callbacks` when you don’t want the body to be automatically decoded. Note that the message will still be decompressed if the message has the `compression` header set.

    The signature of the callback must take a single argument, which is the `Message` object.

    Also note that the `message.body` attribute, which is the raw contents of the message body, may in some cases be a read-only `buffer` object.

  prefetch_count = None

    Initial prefetch count

    If set, the consumer will set the prefetch_count QoS value at startup. Can also be changed using `qos()`.

  process_next()
  purge()

    Purge messages from all queues.

    ### Warning:

    > This will delete all ready messages, there is no undo operation.

  qos(prefetch_size=0, prefetch_count=0, apply_global=False)

    Specify quality of service.

    The client can request that messages should be sent in advance so that when the client finishes processing a message, the following message is already held locally, rather than needing to be sent down the channel. Prefetching gives a performance improvement.

    The prefetch window is Ignored if the `no_ack` option is set.

    ### Arguments:

    > prefetch_size (int): Specify the prefetch window in octets.

    >   The server will send a message in advance if it is equal to or smaller in size than the available prefetch size (and also falls within other prefetch limits). May be set to zero, meaning “no specific limit”, although other prefetch limits may still apply.

    > prefetch_count (int): Specify the prefetch window in terms of

    >   whole messages.

    > apply_global (bool): Apply new settings globally on all channels.

  queue = ''
  property queues
  receive(body, message)

    Method called when a message is received.

    This dispatches to the registered `callbacks`.

    ### Arguments:

    > body (Any): The decoded message body. message (~kombu.Message): The message instance.

    raises NotImplementedError:

      If no consumer callbacks have been: registered.

  recover(requeue=False)

    Redeliver unacknowledged messages.

    Asks the broker to redeliver all unacknowledged messages on the specified channel.

    ### Arguments:

    > requeue (bool): By default the messages will be redelivered

    >   to the original recipient. With requeue set to true, the server will attempt to requeue the message, potentially then delivering it to an alternative subscriber.

  register_callback(callback)

    Register a new callback to be called when a message is received.

    ### Note:

    > The signature of the callback needs to accept two arguments: (body, message), which is the decoded message body and the `Message` instance.

  revive(channel)

    Revive consumer after connection loss.

  routing_key = ''
  wait(limit=None)

## ConsumerSet

Replace with `kombu.Consumer`.

class kombu.compat.ConsumerSet(connection, from_dict=None, consumers=None, channel=None, **kwargs)
  exception ContentDisallowed

    Consumer does not allow this content-type.

    add_note(note, /)

      Add a note to the exception

    args
    with_traceback(tb, /)

      Set self.__traceback__ to tb and return self.

  accept = None

    List of accepted content-types.

    An exception will be raised if the consumer receives a message with an untrusted content type. By default all content-types are accepted, but not if `kombu.disable_untrusted_serializers()` was called, in which case only json is allowed.

  add_consumer(consumer)
  add_consumer_from_dict(queue, **options)
  add_queue(queue)

    Add a queue to the list of queues to consume from.

    ### Note:

    > This will not start consuming from the queue, for that you will have to call `consume()` after.

  auto_declare = True

    By default all entities will be declared at instantiation, if you want to handle this manually you can set this to `False`.

  callbacks = None

    List of callbacks called in order when a message is received.

    The signature of the callbacks must take two arguments: (body, message), which is the decoded message body and the `Message` instance.

  cancel()

    End all active queue consumers.

    ### Note:

    > This does not affect already delivered messages, but it does mean the server will not send any more messages for this consumer.

  cancel_by_queue(queue)

    Cancel consumer by queue name.

  channel = None

    The connection/channel to use for this consumer.

  close()

    End all active queue consumers.

    ### Note:

    > This does not affect already delivered messages, but it does mean the server will not send any more messages for this consumer.

  property connection
  consume(no_ack=None)

    Start consuming messages.

    Can be called multiple times, but note that while it will consume from new queues added since the last call, it will not cancel consuming from removed queues ( use `cancel_by_queue()`).

    ### Arguments:

    > no_ack (bool): See `no_ack`.

  consuming_from(queue)

    Return `True` if currently consuming from queue’.

  declare()

    Declare queues, exchanges and bindings.

    ### Note:

    > This is done automatically at instantiation when `auto_declare` is set.

  discard_all()
  flow(active)

    Enable/disable flow from peer.

    This is a simple flow-control mechanism that a peer can use to avoid overflowing its queues or otherwise finding itself receiving more messages than it can process.

    The peer that receives a request to stop sending content will finish sending the current content (if any), and then wait until flow is reactivated.

  iterconsume(limit=None, no_ack=False)
  no_ack = None

    Flag for automatic message acknowledgment. If enabled the messages are automatically acknowledged by the broker. This can increase performance but means that you have no control of when the message is removed.

    Disabled by default.

  on_decode_error = None

    Callback called when a message can’t be decoded.

    The signature of the callback must take two arguments: (message, exc), which is the message that can’t be decoded and the exception that occurred while trying to decode it.

  on_message = None

    Optional function called whenever a message is received.

    When defined this function will be called instead of the `receive()` method, and `callbacks` will be disabled.

    So this can be used as an alternative to `callbacks` when you don’t want the body to be automatically decoded. Note that the message will still be decompressed if the message has the `compression` header set.

    The signature of the callback must take a single argument, which is the `Message` object.

    Also note that the `message.body` attribute, which is the raw contents of the message body, may in some cases be a read-only `buffer` object.

  prefetch_count = None

    Initial prefetch count

    If set, the consumer will set the prefetch_count QoS value at startup. Can also be changed using `qos()`.

  purge()

    Purge messages from all queues.

    ### Warning:

    > This will delete all ready messages, there is no undo operation.

  qos(prefetch_size=0, prefetch_count=0, apply_global=False)

    Specify quality of service.

    The client can request that messages should be sent in advance so that when the client finishes processing a message, the following message is already held locally, rather than needing to be sent down the channel. Prefetching gives a performance improvement.

    The prefetch window is Ignored if the `no_ack` option is set.

    ### Arguments:

    > prefetch_size (int): Specify the prefetch window in octets.

    >   The server will send a message in advance if it is equal to or smaller in size than the available prefetch size (and also falls within other prefetch limits). May be set to zero, meaning “no specific limit”, although other prefetch limits may still apply.

    > prefetch_count (int): Specify the prefetch window in terms of

    >   whole messages.

    > apply_global (bool): Apply new settings globally on all channels.

  property queues
  receive(body, message)

    Method called when a message is received.

    This dispatches to the registered `callbacks`.

    ### Arguments:

    > body (Any): The decoded message body. message (~kombu.Message): The message instance.

    raises NotImplementedError:

      If no consumer callbacks have been: registered.

  recover(requeue=False)

    Redeliver unacknowledged messages.

    Asks the broker to redeliver all unacknowledged messages on the specified channel.

    ### Arguments:

    > requeue (bool): By default the messages will be redelivered

    >   to the original recipient. With requeue set to true, the server will attempt to requeue the message, potentially then delivering it to an alternative subscriber.

  register_callback(callback)

    Register a new callback to be called when a message is received.

    ### Note:

    > The signature of the callback needs to accept two arguments: (body, message), which is the decoded message body and the `Message` instance.

  revive(channel)

    Revive consumer after connection loss.