Azure Event Hub Not Connecting

Hi,

I am following this tutorial-  https://docs.microsoft.com/en-us/azure/event-hubs/event-hubs-python-get-started-send

to send events to my event hub using Python

The connection string of my Event Hub namespace is in the following format

Endpoint=sb://<eventhubnamespacename>.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=<AcessKeyvalue>

So, in the above mentioned tutorial, I have replaced tutorial I replaced 

ADDRESS with"amqps://mynamespace.servicebus.windows.net/<myeventhub>"
User="RootManageSharedAccessKey"
KEY="<AcessKeyvalue>"

But everytime , I run into errors with the line client.run

'eventhub.pysdk-ANumber': All clients failed to start.

azure.eventhub.common.EventHubError: Unable to open authentication session on connection b'EHSender-anumber-partition0'.
Please confirm target hostname exists: b'eventhubnamespacename.servicebus.windows.net'

I have even tried replacing amqps with sb (as is actually in the connection string but the same error)

Where am I going wrong?