This was changed in Python 3.2+ in Issue 16723. The response object no longer sets the “closed” attribute when it runs out of data; it is only set when the “close” method is called. Perhaps the example should be amended so that it checks if “read” returned an empty string, rather than checking “closed”.

Another problem with the example is that printing the chunk as a bytes object can trigger BytesWarning. I would add a “repr” call to avoid that.