How to Use Azure Blob Storage with Python: Simple Guide

To use Azure Blob Storage with Python, install the azure-storage-blob package, create a BlobServiceClient with your connection string, and then use it to upload or download blobs. This lets you store and retrieve files in the cloud easily from your Python code.

Syntax

Here is the basic syntax to connect and upload a file to Azure Blob Storage using Python:

• BlobServiceClient: Connects to your storage account.
• ContainerClient: Accesses a specific container (folder).
• upload_blob(): Uploads data as a blob (file).

python

from azure.storage.blob import BlobServiceClient

# Connect to the storage account
blob_service_client = BlobServiceClient.from_connection_string('<your_connection_string>')

# Get container client
container_client = blob_service_client.get_container_client('<container_name>')

# Upload a blob
with open('example.txt', 'rb') as data:
    container_client.upload_blob(name='example.txt', data=data, overwrite=True)

Example

This example shows how to upload a text file to Azure Blob Storage and then download it back to verify the content.

python

from azure.storage.blob import BlobServiceClient

connection_string = '<your_connection_string>'
container_name = 'mycontainer'
blob_name = 'sample.txt'
local_file = 'sample.txt'

def upload_blob():
    blob_service_client = BlobServiceClient.from_connection_string(connection_string)
    container_client = blob_service_client.get_container_client(container_name)
    try:
        container_client.create_container()
    except Exception:
        pass  # Container may already exist

    with open(local_file, 'rb') as data:
        container_client.upload_blob(name=blob_name, data=data, overwrite=True)
    print(f'Uploaded {blob_name} to container {container_name}')

def download_blob():
    blob_service_client = BlobServiceClient.from_connection_string(connection_string)
    container_client = blob_service_client.get_container_client(container_name)
    blob_client = container_client.get_blob_client(blob_name)

    download_stream = blob_client.download_blob()
    content = download_stream.readall().decode('utf-8')
    print(f'Downloaded blob content:\n{content}')

if __name__ == "__main__":
    upload_blob()
    download_blob()

Output

Uploaded sample.txt to container mycontainer
Downloaded blob content:
Hello Azure Blob Storage!

Common Pitfalls

• Not installing the azure-storage-blob package before running code.
• Using an incorrect or expired connection string.
• Trying to upload to a container that does not exist without creating it first.
• Not setting overwrite=True when uploading blobs to replace existing files.
• Forgetting to open files in binary mode ('rb') when uploading.

python

from azure.storage.blob import BlobServiceClient

# Wrong: Not opening file in binary mode
with open('file.txt', 'r') as data:
    container_client.upload_blob(name='file.txt', data=data)  # This will fail

# Right: Open file in binary mode
with open('file.txt', 'rb') as data:
    container_client.upload_blob(name='file.txt', data=data, overwrite=True)

Quick Reference

Keep these tips handy when working with Azure Blob Storage in Python:

• Install package: pip install azure-storage-blob
• Use BlobServiceClient.from_connection_string() to connect.
• Create container if missing: container_client.create_container().
• Upload blobs with upload_blob(name, data, overwrite=True).
• Download blobs with download_blob().readall().

Key Takeaways

Install and import the azure-storage-blob package to work with Blob Storage in Python.

Use BlobServiceClient with your connection string to connect to your storage account.

Always open files in binary mode when uploading blobs to avoid errors.

Create containers before uploading blobs if they do not exist.

Set overwrite=True to replace existing blobs when uploading.