QueueClient Class

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A client to interact with a specific Queue.

For more optional configuration, please click here.

Inheritance

azure.storage.queue._shared.base_client.StorageAccountHostsMixin

QueueClient

Constructor

QueueClient(account_url: str, queue_name: str, credential: Optional[Any] = None, **kwargs: Any)

Parameters

account_url

str

Required

The URL to the storage account. In order to create a client given the full URI to the queue, use the from_queue_url classmethod.

queue_name

str

Required

The name of the queue.

credential

default value: None

The credentials with which to authenticate. This is optional if the account URL already has a SAS token. The value can be a SAS token string, an instance of a AzureSasCredential from azure.core.credentials, an account shared access key, or an instance of a TokenCredentials class from azure.identity.

api_version

str

The Storage API version to use for requests. Default value is the most recent service version that is compatible with the current SDK. Setting to an older version may result in reduced feature compatibility.

secondary_hostname

str

The hostname of the secondary endpoint.

message_encode_policy

The encoding policy to use on outgoing messages. Default is not to encode messages. Other options include TextBase64EncodePolicy, BinaryBase64EncodePolicy or None.

message_decode_policy

The decoding policy to use on incoming messages. Default value is not to decode messages. Other options include TextBase64DecodePolicy, BinaryBase64DecodePolicy or None.

Examples

Create the queue client with url and credential.

   token_auth_queue = QueueClient.from_queue_url(
       queue_url=queue.url,
       credential=sas_token
   )

Methods

clear_messages	Deletes all messages from the specified queue.
create_queue	Creates a new queue in the storage account. If a queue with the same name already exists, the operation fails with a ResourceExistsError.
delete_message	Deletes the specified message. Normally after a client retrieves a message with the receive messages operation, the client is expected to process and delete the message. To delete the message, you must have the message object itself, or two items of data: id and pop_receipt. The id is returned from the previous receive_messages operation. The pop_receipt is returned from the most recent receive_messages or update_message operation. In order for the delete_message operation to succeed, the pop_receipt specified on the request must match the pop_receipt returned from the receive_messages or update_message operation.
delete_queue	Deletes the specified queue and any messages it contains. When a queue is successfully deleted, it is immediately marked for deletion and is no longer accessible to clients. The queue is later removed from the Queue service during garbage collection. Note that deleting a queue is likely to take at least 40 seconds to complete. If an operation is attempted against the queue while it was being deleted, an <xref:azure.storage.queue.HttpResponseError> will be thrown.
from_connection_string	Create QueueClient from a Connection String.
from_queue_url	A client to interact with a specific Queue.
get_queue_access_policy	Returns details about any stored access policies specified on the queue that may be used with Shared Access Signatures.
get_queue_properties	Returns all user-defined metadata for the specified queue. The data returned does not include the queue's list of messages.
peek_messages	Retrieves one or more messages from the front of the queue, but does not alter the visibility of the message. Only messages that are visible may be retrieved. When a message is retrieved for the first time with a call to receive_messages, its dequeue_count property is set to 1. If it is not deleted and is subsequently retrieved again, the dequeue_count property is incremented. The client may use this value to determine how many times a message has been retrieved. Note that a call to peek_messages does not increment the value of dequeue_count, but returns this value for the client to read. If the key-encryption-key or resolver field is set on the local service object, the messages will be decrypted before being returned.
receive_message	Removes one message from the front of the queue. When the message is retrieved from the queue, the response includes the message content and a pop_receipt value, which is required to delete the message. The message is not automatically deleted from the queue, but after it has been retrieved, it is not visible to other clients for the time interval specified by the visibility_timeout parameter. If the key-encryption-key or resolver field is set on the local service object, the message will be decrypted before being returned.
receive_messages	Removes one or more messages from the front of the queue. When a message is retrieved from the queue, the response includes the message content and a pop_receipt value, which is required to delete the message. The message is not automatically deleted from the queue, but after it has been retrieved, it is not visible to other clients for the time interval specified by the visibility_timeout parameter. The iterator will continuously fetch messages until the queue is empty or max_messages is reached (if max_messages is set). If the key-encryption-key or resolver field is set on the local service object, the messages will be decrypted before being returned.
send_message	Adds a new message to the back of the message queue. The visibility timeout specifies the time that the message will be invisible. After the timeout expires, the message will become visible. If a visibility timeout is not specified, the default value of 0 is used. The message time-to-live specifies how long a message will remain in the queue. The message will be deleted from the queue when the time-to-live period expires. If the key-encryption-key field is set on the local service object, this method will encrypt the content before uploading.
set_queue_access_policy	Sets stored access policies for the queue that may be used with Shared Access Signatures. When you set permissions for a queue, the existing permissions are replaced. To update the queue's permissions, call get_queue_access_policy to fetch all access policies associated with the queue, modify the access policy that you wish to change, and then call this function with the complete set of data to perform the update. When you establish a stored access policy on a queue, it may take up to 30 seconds to take effect. During this interval, a shared access signature that is associated with the stored access policy will throw an <xref:azure.storage.queue.HttpResponseError> until the access policy becomes active.
set_queue_metadata	Sets user-defined metadata on the specified queue. Metadata is associated with the queue as name-value pairs.
update_message	Updates the visibility timeout of a message. You can also use this operation to update the contents of a message. This operation can be used to continually extend the invisibility of a queue message. This functionality can be useful if you want a worker role to "lease" a queue message. For example, if a worker role calls receive_messages and recognizes that it needs more time to process a message, it can continually extend the message's invisibility until it is processed. If the worker role were to fail during processing, eventually the message would become visible again and another worker role could process it. If the key-encryption-key field is set on the local service object, this method will encrypt the content before uploading.

clear_messages

Deletes all messages from the specified queue.

clear_messages(**kwargs: Any) -> None

Parameters

timeout

int

The server timeout, expressed in seconds.

Examples

Clears all messages.

   queue.clear_messages()

create_queue

Creates a new queue in the storage account.

If a queue with the same name already exists, the operation fails with a ResourceExistsError.

create_queue(**kwargs: Any) -> None

Parameters

metadata

dict(<xref:str,str>)

A dict containing name-value pairs to associate with the queue as metadata. Note that metadata names preserve the case with which they were created, but are case-insensitive when set or read.

timeout

int

The server timeout, expressed in seconds.

Returns

None or the result of cls(response)

Return type

None

Exceptions

StorageErrorException

Examples

Create a queue.

   queue.create_queue()

delete_message

Deletes the specified message.

Normally after a client retrieves a message with the receive messages operation, the client is expected to process and delete the message. To delete the message, you must have the message object itself, or two items of data: id and pop_receipt. The id is returned from the previous receive_messages operation. The pop_receipt is returned from the most recent receive_messages or update_message operation. In order for the delete_message operation to succeed, the pop_receipt specified on the request must match the pop_receipt returned from the receive_messages or update_message operation.

delete_message(message: Any, pop_receipt: Optional[str] = None, **kwargs: Any) -> None

Parameters

message

str or QueueMessage

Required

The message object or id identifying the message to delete.

pop_receipt

str

Required

A valid pop receipt value returned from an earlier call to the receive_messages or update_message.

timeout

int

The server timeout, expressed in seconds.

Examples

Delete a message.

   # Get the message at the front of the queue
   msg = next(queue.receive_messages())

   # Delete the specified message
   queue.delete_message(msg)

delete_queue

Deletes the specified queue and any messages it contains.

When a queue is successfully deleted, it is immediately marked for deletion and is no longer accessible to clients. The queue is later removed from the Queue service during garbage collection.

Note that deleting a queue is likely to take at least 40 seconds to complete. If an operation is attempted against the queue while it was being deleted, an <xref:azure.storage.queue.HttpResponseError> will be thrown.

delete_queue(**kwargs: Any) -> None

Parameters

timeout

int

The server timeout, expressed in seconds.

Return type

None

Examples

Delete a queue.

   queue.delete_queue()

from_connection_string

Create QueueClient from a Connection String.

from_connection_string(conn_str: str, queue_name: str, credential: Optional[Any] = None, **kwargs: Any) -> azure.storage.queue._queue_client.QueueClient

Parameters

conn_str

str

Required

A connection string to an Azure Storage account.

queue_name

str

Required

The queue name.

credential

Required

The credentials with which to authenticate. This is optional if the account URL already has a SAS token, or the connection string already has shared access key values. The value can be a SAS token string, an instance of a AzureSasCredential from azure.core.credentials, an account shared access key, or an instance of a TokenCredentials class from azure.identity.

credential

default value: None

Returns

A queue client.

Return type

QueueClient

Examples

Create the queue client from connection string.

   from azure.storage.queue import QueueClient
   queue = QueueClient.from_connection_string(self.connection_string, "myqueue1")

from_queue_url

A client to interact with a specific Queue.

from_queue_url(queue_url: str, credential: Optional[Any] = None, **kwargs: Any) -> azure.storage.queue._queue_client.QueueClient

Parameters

queue_url

str

Required

The full URI to the queue, including SAS token if used.

credential

Required

The credentials with which to authenticate. This is optional if the account URL already has a SAS token. The value can be a SAS token string, an instance of a AzureSasCredential from azure.core.credentials, an account shared access key, or an instance of a TokenCredentials class from azure.identity.

credential

default value: None

Returns

A queue client.

Return type

QueueClient

get_queue_access_policy

Returns details about any stored access policies specified on the queue that may be used with Shared Access Signatures.

get_queue_access_policy(**kwargs: Any) -> Dict[str, azure.storage.queue._models.AccessPolicy]

Parameters

timeout

int

The server timeout, expressed in seconds.

Returns

A dictionary of access policies associated with the queue.

Return type

dict(str, AccessPolicy)

get_queue_properties

Returns all user-defined metadata for the specified queue.

The data returned does not include the queue's list of messages.

get_queue_properties(**kwargs: Any) -> QueueProperties

Parameters

timeout

int

The timeout parameter is expressed in seconds.

Returns

User-defined metadata for the queue.

Return type

QueueProperties

Examples

Get the properties on the queue.

   properties = queue.get_queue_properties().metadata

peek_messages

Retrieves one or more messages from the front of the queue, but does not alter the visibility of the message.

Only messages that are visible may be retrieved. When a message is retrieved for the first time with a call to receive_messages, its dequeue_count property is set to 1. If it is not deleted and is subsequently retrieved again, the dequeue_count property is incremented. The client may use this value to determine how many times a message has been retrieved. Note that a call to peek_messages does not increment the value of dequeue_count, but returns this value for the client to read.

If the key-encryption-key or resolver field is set on the local service object, the messages will be decrypted before being returned.

peek_messages(max_messages: Optional[int] = None, **kwargs: Any) -> List[azure.storage.queue._models.QueueMessage]

Parameters

max_messages

int

Required

A nonzero integer value that specifies the number of messages to peek from the queue, up to a maximum of 32. By default, a single message is peeked from the queue with this operation.

timeout

int

The server timeout, expressed in seconds.

Returns

A list of QueueMessage objects. Note that next_visible_on and pop_receipt will not be populated as peek does not pop the message and can only retrieve already visible messages.

Return type

list(QueueMessage)

Examples

Peek messages.

   # Peek at one message at the front of the queue
   msg = queue.peek_messages()

   # Peek at the last 5 messages
   messages = queue.peek_messages(max_messages=5)

   # Print the last 5 messages
   for message in messages:
       print(message.content)

receive_message

Removes one message from the front of the queue.

When the message is retrieved from the queue, the response includes the message content and a pop_receipt value, which is required to delete the message. The message is not automatically deleted from the queue, but after it has been retrieved, it is not visible to other clients for the time interval specified by the visibility_timeout parameter.

If the key-encryption-key or resolver field is set on the local service object, the message will be decrypted before being returned.

receive_message(**kwargs: Any) -> azure.storage.queue._models.QueueMessage

Parameters

visibility_timeout

int

If not specified, the default value is 0. Specifies the new visibility timeout value, in seconds, relative to server time. The value must be larger than or equal to 0, and cannot be larger than 7 days. The visibility timeout of a message cannot be set to a value later than the expiry time. visibility_timeout should be set to a value smaller than the time-to-live value.

timeout

int

The server timeout, expressed in seconds.

Returns

Returns a message from the Queue.

Return type

QueueMessage

Examples

Receive one message from the queue.

   # Pop two messages from the front of the queue
   message1 = queue.receive_message()
   message2 = queue.receive_message()
   # We should see message 3 if we peek
   message3 = queue.peek_messages()[0]

   print(message1.content)
   print(message2.content)
   print(message3.content)

receive_messages

Removes one or more messages from the front of the queue.

When a message is retrieved from the queue, the response includes the message content and a pop_receipt value, which is required to delete the message. The message is not automatically deleted from the queue, but after it has been retrieved, it is not visible to other clients for the time interval specified by the visibility_timeout parameter. The iterator will continuously fetch messages until the queue is empty or max_messages is reached (if max_messages is set).

If the key-encryption-key or resolver field is set on the local service object, the messages will be decrypted before being returned.

receive_messages(**kwargs: Any) -> azure.core.paging.ItemPaged[azure.storage.queue._models.QueueMessage]

Parameters

visibility_timeout

int

If not specified, the default value is 30. Specifies the new visibility timeout value, in seconds, relative to server time. The value must be larger than or equal to 1, and cannot be larger than 7 days. The visibility timeout of a message cannot be set to a value later than the expiry time. visibility_timeout should be set to a value smaller than the time-to-live value.

timeout

int

The server timeout, expressed in seconds.

max_messages

int

An integer that specifies the maximum number of messages to retrieve from the queue.

Returns

Returns a message iterator of dict-like Message objects.

Return type

ItemPaged[QueueMessage]

Examples

Receive messages from the queue.

   # Receive messages one-by-one
   messages = queue.receive_messages()
   for msg in messages:
       print(msg.content)

   # Receive messages by batch
   messages = queue.receive_messages(messages_per_page=5)
   for msg_batch in messages.by_page():
       for msg in msg_batch:
           print(msg.content)
           queue.delete_message(msg)

send_message

Adds a new message to the back of the message queue.

The visibility timeout specifies the time that the message will be invisible. After the timeout expires, the message will become visible. If a visibility timeout is not specified, the default value of 0 is used.

The message time-to-live specifies how long a message will remain in the queue. The message will be deleted from the queue when the time-to-live period expires.

If the key-encryption-key field is set on the local service object, this method will encrypt the content before uploading.

send_message(content: Any, **kwargs: Any) -> azure.storage.queue._models.QueueMessage

Parameters

content

<xref:obj>

Required

Message content. Allowed type is determined by the encode_function set on the service. Default is str. The encoded message can be up to 64KB in size.

visibility_timeout

int

If not specified, the default value is 0. Specifies the new visibility timeout value, in seconds, relative to server time. The value must be larger than or equal to 0, and cannot be larger than 7 days. The visibility timeout of a message cannot be set to a value later than the expiry time. visibility_timeout should be set to a value smaller than the time-to-live value.

time_to_live

int

Specifies the time-to-live interval for the message, in seconds. The time-to-live may be any positive number or -1 for infinity. If this parameter is omitted, the default time-to-live is 7 days.

timeout

int

The server timeout, expressed in seconds.

Returns

A QueueMessage object. This object is also populated with the content although it is not returned from the service.

Return type

QueueMessage

Examples

Send messages.

   queue.send_message(u"message1")
   queue.send_message(u"message2", visibility_timeout=30)  # wait 30s before becoming visible
   queue.send_message(u"message3")
   queue.send_message(u"message4")
   queue.send_message(u"message5")

set_queue_access_policy

Sets stored access policies for the queue that may be used with Shared Access Signatures.

When you set permissions for a queue, the existing permissions are replaced. To update the queue's permissions, call get_queue_access_policy to fetch all access policies associated with the queue, modify the access policy that you wish to change, and then call this function with the complete set of data to perform the update.

When you establish a stored access policy on a queue, it may take up to 30 seconds to take effect. During this interval, a shared access signature that is associated with the stored access policy will throw an <xref:azure.storage.queue.HttpResponseError> until the access policy becomes active.

set_queue_access_policy(signed_identifiers: Dict[str, azure.storage.queue._models.AccessPolicy], **kwargs: Any) -> None

Parameters

signed_identifiers

dict(str, AccessPolicy)

Required

SignedIdentifier access policies to associate with the queue. This may contain up to 5 elements. An empty dict will clear the access policies set on the service.

timeout

int

The server timeout, expressed in seconds.

Examples

Set an access policy on the queue.

   # Create an access policy
   from azure.storage.queue import AccessPolicy, QueueSasPermissions
   access_policy = AccessPolicy()
   access_policy.start = datetime.utcnow() - timedelta(hours=1)
   access_policy.expiry = datetime.utcnow() + timedelta(hours=1)
   access_policy.permission = QueueSasPermissions(read=True)
   identifiers = {'my-access-policy-id': access_policy}

   # Set the access policy
   queue.set_queue_access_policy(identifiers)

set_queue_metadata

Sets user-defined metadata on the specified queue.

Metadata is associated with the queue as name-value pairs.

set_queue_metadata(metadata: Optional[Dict[str, Any]] = None, **kwargs: Any) -> None

Parameters

metadata

dict(str, str)

Required

A dict containing name-value pairs to associate with the queue as metadata.

timeout

int

The server timeout, expressed in seconds.

Examples

Set metadata on the queue.

   metadata = {'foo': 'val1', 'bar': 'val2', 'baz': 'val3'}
   queue.set_queue_metadata(metadata=metadata)

update_message

Updates the visibility timeout of a message. You can also use this operation to update the contents of a message.

This operation can be used to continually extend the invisibility of a queue message. This functionality can be useful if you want a worker role to "lease" a queue message. For example, if a worker role calls receive_messages and recognizes that it needs more time to process a message, it can continually extend the message's invisibility until it is processed. If the worker role were to fail during processing, eventually the message would become visible again and another worker role could process it.

If the key-encryption-key field is set on the local service object, this method will encrypt the content before uploading.

update_message(message: Any, pop_receipt: Optional[str] = None, content: Optional[Any] = None, **kwargs: Any) -> azure.storage.queue._models.QueueMessage

Parameters

message

str or QueueMessage

Required

The message object or id identifying the message to update.

pop_receipt

str

Required

A valid pop receipt value returned from an earlier call to the receive_messages or update_message operation.

content

<xref:obj>

Required

Message content. Allowed type is determined by the encode_function set on the service. Default is str.

visibility_timeout

int

Specifies the new visibility timeout value, in seconds, relative to server time. The new value must be larger than or equal to 0, and cannot be larger than 7 days. The visibility timeout of a message cannot be set to a value later than the expiry time. A message can be updated until it has been deleted or has expired. The message object or message id identifying the message to update.

timeout

int

The server timeout, expressed in seconds.

Returns

A QueueMessage object. For convenience, this object is also populated with the content, although it is not returned by the service.

Return type

QueueMessage

Examples

Update a message.

   # Send a message
   queue.send_message(u"update me")

   # Receive the message
   messages = queue.receive_messages()

   # Update the message
   list_result = next(messages)
   message = queue.update_message(
       list_result.id,
       pop_receipt=list_result.pop_receipt,
       visibility_timeout=0,
       content=u"updated")