In the Azure functions Python SDK, how do I get the number of topics for a given namespace?

Question

I'm using Python 3.8 with azure-mgmt-servicebus= v. 1.0.0. I would like to get the number of topics for a given namespace. I have tried the below ...

credential = ServicePrincipalCredentials(self._client_id, self._client_secret, tenant=self._tenant)
        sb_client = ServiceBusManagementClient(credential, self._subscription)
         ...
        topics = sb_client.topics.list_by_namespace(
                resource_group_name=self._resource_group_name,
                namespace_name=namespace
            )
            num_topics = 0
            while topics.current_page:
                num_topics += topics.current_page.count
                topics.next
            logging.info("num topics: %s", num_topics)

My "num_topics" consistently comes back with zero, despite the fact I have verified that my connection is being made (I can create a topic with the same connection) and I can see many topics for the given information in the Azure portal. I'm thinking I'm not using the API properly but am unsure where things are falling apart. How do I get the number of topics for a given namespace?

Answer 1

If you want to get the number of the topics for a given service bus namespace, you could use the code below.

from azure.common.credentials import ServicePrincipalCredentials
from azure.mgmt.servicebus import ServiceBusManagementClient

subscription_id = "<subscription-id>"
rg_name = "<resource-group-name>"

tenant_id = "<tenant-id>"
client_id = "<client-id>"
client_secret = "<client-secret>"

credential = ServicePrincipalCredentials(client_id=client_id, secret=client_secret, tenant=tenant_id)
sb_client = ServiceBusManagementClient(credential, subscription_id)
topics = sb_client.topics.list_by_namespace(resource_group_name= rg_name, namespace_name= "servicebusname")

num_topics = 0
for topic in topics:
    num_topics += 1
print(num_topics)

Check the topics in the portal, the result is correct:

Update:

If you don't want to use the loop, you could convert the topics to a list, then use the len() function.

from azure.common.credentials import ServicePrincipalCredentials
from azure.mgmt.servicebus import ServiceBusManagementClient

subscription_id = "<subscription-id>"
rg_name = "<resource-group-name>"

tenant_id = "<tenant-id>"
client_id = "<client-id>"
client_secret = "<client-secret>"

credential = ServicePrincipalCredentials(client_id=client_id, secret=client_secret, tenant=tenant_id)
sb_client = ServiceBusManagementClient(credential, subscription_id)
topics = sb_client.topics.list_by_namespace(resource_group_name= rg_name, namespace_name= "servicebusname")

testlist = list(topics)
print(len(testlist))