Fix Python – How do I fix PyDev “Undefined variable from import” errors?

I’ve got a Python project using PyDev in Eclipse, and PyDev keeps generating false errors for my code. I have a module settings that defines a settings object. I import that in module b and assign an attribute with:
from settings import settings
settings.main = object()

In some of my code–but not all of it, statements like:
from settings impor….