Help: Eric Python IDE Autocompletion not working?

I install Eric4 on Trisquel 7. I'd like to have code autocompletion. For example, I type

import os
os. # // here I expect to have a list appearing

To enable autocompletion, I followed the similar steps as

http://www.aichengxu.com/python/7034289.htm

But not working.

Anyone can help?

Thanks!