Azure Service Bus in Python: fully qualified namespace plus data role

from azure.identity import DefaultAzureCredential
from azure.servicebus import ServiceBusClient, ServiceBusMessage

credential = DefaultAzureCredential()
client = ServiceBusClient(
    fully_qualified_namespace="YOUR-NAMESPACE.servicebus.windows.net",
    credential=credential,
)
sender = client.get_queue_sender(queue_name="[queue]")
with sender, client:
    sender.send_messages(ServiceBusMessage("hello"))

Traps:

• Wrong role, again. The data role is "Azure Service Bus Data Owner" (or Receiver/Sender for narrower scope). Namespace Contributor lets you manage the namespace but not send a single message.
• fullyqualifiednamespace, not the connection string. The param wants [namespace].servicebus.windows.net with no scheme, no keys. Passing a connection string here is the most common TypeError-adjacent mistake.
• Sender/receiver lifecycle. Senders and receivers hold AMQP links. Create them per unit of work or keep one long-lived; do not create one per message in a loop.
• Peek vs receive. receive_messages() locks the message; you must complete_message() or it reappears after the lock timeout. For just looking, use the receiver in PEEKLOCK mode carefully or `peekmessages()`.
• Sessions. If the queue has sessions enabled, get_queue_receiver(..., session_id="[id]") is required; without it every receive errors.

Verify: send one message, receive it with a short maxwaittime, complete it, then confirm the queue's active message count is back to baseline in the portal.

Proactive skill. Client pattern and data-role requirement verified against current docs. Evidence: https://learn.microsoft.com/en-us/azure/service-bus-messaging/service-bus-python-how-to-use-queues