Getting Started

These extensions allows for supported trigger and input types in Python Function Apps to recognize and bind to client types from the Azure SDK.

Supported binding types include:

• Blob Triggers
• Blob Input

Getting started with Blobs

Prerequisites

• Python 3.9 or later is required to use this package.

• You must have an Azure subscription and an Azure storage account to use this package.

Install the package

Install the Azure Functions Extension Blob library for Python with pip:

pip install azure-functions-extension-blob

Create a storage account

If you wish to create a new storage account, you can use the Azure Portal, Azure PowerShell, or Azure CLI:

# Create a new resource group to hold the storage account -
# if using an existing resource group, skip this step
az group create --name my-resource-group --location westus2

# Create the storage account
az storage account create -n my-storage-account-name -g my-resource-group

Bind to the SDK-type

The Azure Functions Extension Blob library for Python allows you to create a function app with a Blob Trigger or Blob Input and define the type as a BlobClient, ContainerClient, or StorageStreamDownloader. Instead of receiving an InputStream, when the function is executed, the type returned will be the defined SDK-type and have all of the properties and methods available as seen in the Azure Storage Blob library for Python.

import logging
import azure.functions as func
import azure.functions.extension.blob as blob

@app.blob_trigger(arg_name="client",
                  path="PATH/TO/BLOB",
                  connection="AzureWebJobsStorage")
def blob_trigger(client: blob.BlobClient):
    logging.info(f"Python blob trigger function processed blob \n"
                 f"Properties: {client.get_blob_properties()}\n"
                 f"Blob content: {client.download_blob(encoding="utf-8").readall()}")


@app.route(route="file")
@app.blob_input(arg_name="client",
                path="PATH/TO/BLOB",
                connection="AzureWebJobsStorage")
def blob_input(req: func.HttpRequest, client: blob.BlobClient):
    logging.info(f"Python blob input function processed blob \n"
                 f"Properties: {client.get_blob_properties()}\n"
                 f"Blob content: {client.download_blob(encoding="utf-8").readall()}")

Troubleshooting

General

The SDK-types raise exceptions defined in Azure Core.

This list can be used for reference to catch thrown exceptions. To get the specific error code of the exception, use the error_code attribute, i.e, exception.error_code.

Next steps

More sample code

Get started with our Blob samples.

Several samples are available in this GitHub repository. These samples provide example code for additional scenarios commonly encountered while working with Storage Blobs:

• blob_samples_blobclient - Examples for using the BlobClient type:

  • From BlobTrigger
  • From BlobInput

• blob_samples_containerclient - Examples for using the ContainerClient type:

  • From BlobTrigger
  • From BlobInput

• blob_samples_storagestreamdownloader - Examples for using the StorageStreamDownloader type:

  • From BlobTrigger
  • From BlobInput

Additional documentation

For more information on the Azure Storage Blob SDK, see the Azure Blob storage documentation on docs.microsoft.com and the Azure Storage Blobs README.