I've recently ported my Python project to run on Python 3.1. For that I had to adopt the policy of relative imports within the submodules and subpackages of my project. I've don’t that and now the project itself works, but I noticed I can't execute any of the subpackages or submodules in it. If I try, I get "builtins.ValueError: Attempted relative import in non-package". I can only import the whole project.

Is this normal?