I'm not sure why it won't work, it may be an issue that you can't work around, but I would just like to know why it won't work. I am sorry if I waste your time, or didn't ask the question properly, I'm 16 and new to Python kind of.
in main.py
from day_one import day_one_def
in day_one.py
from main import main_home_window
error message
ImportError: cannot import name 'day_one'