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azure-storage-queue

README.md

Azure Storage Queues client library for Python

Azure Storage Queues is a service for storing large numbers of messages that can be accessed from anywhere in the world via authenticated calls using HTTP or HTTPS. A single queue message can be up to 64 KB in size, and a queue can contain millions of messages, up to the total capacity limit of a storage account.

Common uses of Queue storage include:

  • Creating a backlog of work to process asynchronously
  • Passing messages between different parts of a distributed application

Source code | Package (PyPi) | API reference documentation | Product documentation | Samples

Getting started

Install the package

Install the Azure Storage Queue client library for Python with pip:

pip install azure-storage-queue --pre

Prerequisites: You must have an Azure subscription, and a Storage Account to use this package.

To create a Storage Account, you can use the Azure Portal, Azure PowerShell or Azure CLI:

az storage account create -n MyStorageAccountName -g MyResourceGroupName

Requires Python 2.7, 3.5 or later to use this package.

Authenticate the client

Interaction with Storage Queues starts with an instance of the QueueServiceClient class. You need an existing storage account, its URL, and a credential to instantiate the client object.

Get credentials

To authenticate the client you have a few options:

  1. Use a SAS token string
  2. Use an account shared access key
  3. Use a token credential from azure.identity

Alternatively, you can authenticate with a storage connection string using the from_connection_string method. See example: Client creation with a connection string.

You can omit the credential if your account URL already has a SAS token.

Create client

Once you have your account URL and credentials ready, you can create the QueueServiceClient:

from azure.storage.queue import QueueServiceClient

service = QueueServiceClient(account_url="https://<my-storage-account-name>.queue.core.windows.net/", credential=credential)

Key concepts

The Queue service contains the following components:

  • The storage account
  • A queue which contains a set of messages
  • A message, in any format, of up to 64 KB

Clients

The Storage Queues SDK provides two different clients to interact with the Queues Service:

  1. QueueServiceClient - this client interacts with the Queue Service at the account level. It provides operations to retrieve and configure the account properties as well as list, create, and delete queues within the account. For operations relating to a specific queue, a client for that entity can also be retrieved using the get_queue_client function.
  2. QueueClient - this client represents interaction with a specific queue, although that queue need not exist yet. It provides operations to create, delete, or configure queues and includes operations to enqueue, receive, peak, delete, and update messages in the queue.

Messages

Once you've initialized a Client, you can use the following operations to work with the messages in the queue:

  • Enqueue - Adds a message to the queue and optionally sets a visibility timeout for the message.
  • Receive - Retrieves a message from the queue and makes it invisible to other consumers.
  • Peek - Retrieves a message from the front of the queue, without changing the message visibility.
  • Update - Updates the visibility timeout of a message and/or the message contents.
  • Delete - Deletes a specified message from the queue.
  • Clear - Clears all messages from the queue.

Examples

The following sections provide several code snippets covering some of the most common Storage Queue tasks, including:

Client creation with a connection string

Create the QueueServiceClient using the connection string to your Azure Storage account.

from azure.storage.queue import QueueServiceClient

service = QueueServiceClient.from_connection_string(conn_str="my_connection_string")

Create a queue

Create a queue in your storage account.

from azure.storage.queue import QueueClient

queue = QueueClient.from_connection_string(conn_str="my_connection_string", queue="myqueue")
queue.create_queue()

Create a queue asynchronously.

from azure.storage.queue.aio import QueueClient

queue = QueueClient.from_connection_string(conn_str="my_connection_string", queue="myqueue")
await queue.create_queue()

Enqueue messages

Enqueue a message in your queue.

from azure.storage.queue import QueueClient

queue = QueueClient.from_connection_string(conn_str="my_connection_string", queue="myqueue")
queue.enqueue_message("I'm using queues!")
queue.enqueue_message("This is my second message")

Enqueue messages with an async client

from azure.storage.queue.aio import QueueClient

queue = QueueClient.from_connection_string(conn_str="my_connection_string", queue="myqueue")
await asyncio.gather(
    queue.enqueue_message("I'm using queues!"),
    queue.enqueue_message("This is my second message"))

Receive messages

Receive messages from your queue.

from azure.storage.queue import QueueClient

queue = QueueClient.from_connection_string(conn_str="my_connection_string", queue="myqueue")
response = queue.receive_messages()

for message in response:
    print(message.content)
    queue.delete_message(message)

# Printed messages from the front of the queue
# >>I'm using queues!   
# >>This is my second message

Receive messages by batch.

queue = QueueClient.from_connection_string(conn_str="my_connection_string", queue="myqueue")
response = queue.receive_messages(messages_per_page=10)

for message_batch in response.by_page():
    for message in message_batch:
        print(message.content)
        queue.delete_message(message)

Receive messages asynchronously:

from azure.storage.queue.aio import QueueClient

queue = QueueClient.from_connection_string(conn_str="my_connection_string", queue="myqueue")
response = queue.receive_messages()

async for message in response:
    print(message.content)
    await queue.delete_message(message)

Troubleshooting

Storage Queue clients raise exceptions defined in Azure Core.

All Queue service operations will throw a StorageErrorException on failure with helpful error codes.

Next steps

More sample code

Get started with our Queue samples.

Several Storage Queues Python SDK samples are available to you in the SDK's GitHub repository. These samples provide example code for additional scenarios commonly encountered while working with Storage Queues:

Additional documentation

For more extensive documentation on the Azure Storage Queues, see the Azure Storage Queues documentation on docs.microsoft.com.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.