I'm starting with Python 3, using Raspbian (from Debian), and using virtualenv.  I understand how to create/use a virtualenv to "sandbox" different Python project, HOWEVER I'm a bit unclear on whether one should be setting up a different linux user for each project (assuming that the project/virtualenv will be used to create & then run a daemon process on the linux box).  
So when creating separate python environments the question I think is should I be:

creating a new linux user account for each deamon/acript I'm working on, so that both the python virtual environment, and the python project code area can live under directories owned by this user?
perhaps just create one new non-administrator account at the beginning, and then just use this account for each project/virtual environmnet
create everything under the initial admin user I first log with for raspbian (e.g. "pi" user) - Assume NO for this option, but putting it in for completeness.
It depends on what you're trying to achieve. From virtualenv's perspective you could do any of those.
#1 makes sense to me if you have multiple services that are publicly accessible and want to isolate them.
If you're running trusted code on an internal network, but don't want the dependencies clashing then #2 sounds reasonable.
Given that the Pi is often used for a specific purpose (not a general purpose desktop say) and the default account goes largely unused, using that account would be fine. Make sure to change the default password.
should new python virtualenv's be created with new linux user accounts?