ModuleNotFoundError: No module named 'reportlab.pdfgen'; 'reportlab' is not a package

I am not sure if this is the place to put my question,comment. but here goes

I am trying to run Reportlab on Ubuntu 16.04 and have python3.6 as 
default. am running idle3 which opens python3.6 and trying to run 
reportlab.py from the step by step tutorial by Mickeal Driscoll.

so I put it in idle3 and run it and get this

ModuleNotFoundError: No module named 'reportlab.pdfgen'; 'reportlab' is 
not a package

So idle is not seeing reportlab which is installed etc. I am at my wits 
end trying to get this up. I have tried setting the path and pythonpath 
in /.profiles and etc/enviorment to no avail. When I import at the 
python shell it seems to import. but idle3 which runs in python 3.6.4 
does not see it.

I really want this to work but until I can open it up whats the point? Help!

Peter