Embarrassingly basic question but I've been away from Python awhile.

I'm thinking about structuring my project like

src/core/core.py # main entry point
src/build/pocket.py # build script
src/simulate/pocket.py # build script

Say I run one of these like `pdm run src/simulate/pocket.py`. What would simulate/pocket need to do to import stuff from core/core? Will/can pdm automatically expose my project root as a thing I can import, like andi.core.core? Do I need to set a PYTHONPATH? Is there another trick I've forgotten?