Retrieve data from TTN by using Python SDK

Hi,
I have a problem in retrieving data from TTN by using Python SDK. I was using python SDK and having a problem. I run the example code from here https://www.thethingsnetwork.org/docs/applications/python/. I have changed the app_id and access_key in that code to my own.

This is the result when I run the code by using Anaconda Prompt:

The problem is the data is not continue received from TTN.
Can any one help me?

Thanks