Attempted relative import beyond top-level package with Python

Question

I have seen several questions related to this error but I think they are different cases. My Django project has 2 applications and a directory structure like this and I'm facing an issue with relative imports I don't understand the logic.

Python allows me to import market from file my_app2/signals.py but it returns ValueError: attempted relative import beyond top-level package if I import portfolio from file my_app1/signals.py . What is the reason and how can I found a wordaround?

/my_project
  /my_project
    __init__.py
  /my_app1
    market.py
    signals.py  #  Here I can't import portfolio.py
  /my_app2
    portfolio.py 
    signals.py  #  Here I can import market.py

my_app1/signals.py

from ..my_app2 import portfolio #  doesn't work
ValueError: attempted relative import beyond top-level package

from my_project.my_app2 import portfolio #  doesn't work
ModuleNotFoundError: No module named 'my_project.my_app2'

my_app2/signals.py

from ..my_app1 import market #  works

Answer 1

I finally solved the issue without the use of from , it's not clear for me what was causing the error.

import my_app2.portfolio as portfolio