When you use a user-assigned identity, you need to specify the client_id of the MSI in ManagedIdentityCredential().

credential = ManagedIdentityCredential(client_id="xxxxxxxx")

To get the client_id, navigate to your function app -> Identity -> User assigned -> click your user-assigned identity -> copy the client_id.

Use with AIThis request is not authorized to perform this operation using this permission.

If the service principal doesn't have permissions to read or perform the operations, you will get the above error. To resolve the error add storage data contributor role to the service principle to blob storage account as follows: Step1: Go to IAM of storage account, click on Add and select Add role assignment as shown below:

Step2: Search for storage data contributor role and select it as shown below:

Step3: Select the service principle as mentioned below:

After successful role assignment you will be able to read file or list the files in container using below code:

Use with AIimport io
from azure.storage.blob import BlobServiceClient
import pandas as pd
from azure.identity import ClientSecretCredential

account_url = "https://<storageAccountName>.blob.core.windows.net"
container_name = "<containerNmae>"
file_path = "<filePath>"
TENANT_ID = "<tenantId>"
CLIENT_ID = "clientId"
CLIENT_SECRET = "clientSecret"
credentials = ClientSecretCredential(TENANT_ID, CLIENT_ID, CLIENT_SECRET)
blob_service_client = BlobServiceClient(account_url=account_url, credential=credentials)
container_client = blob_service_client.get_container_client(container_name)
blobs_list = container_client.list_blobs()
for blob in blobs_list:
    print(blob.name)
blob_client = container_client.get_blob_client(file_path) 
blob_data = blob_client.download_blob()
csv_data = blob_data.content_as_text()
df = pd.read_csv(io.StringIO(csv_data))
print("Sample.CSV data:")
print(df)

When using Azure Identity client library for Python, DefaultAzureCredential attempts to authenticate via the following mechanisms in this order, stopping when one succeeds:

You could set Environment Variables to fix it.

from azure.identity import DefaultAzureCredential

credential=DefaultAzureCredential()

Or set the properties in config and use ClientSecretCredential to create credential.

from azure.identity import ClientSecretCredential

subscription_id = creds_obj["AZURE_SUBSCRIPTION_ID"]
tenant_id = creds_obj["AZURE_TENANT_ID"]
client_id = creds_obj["AZURE_CLIENT_ID"]
client_secret = creds_obj["AZURE_CLIENT_SECRET"]

credential = ClientSecretCredential(tenant_id=tenant_id, client_id=client_id, client_secret=client_secret)