Importing Module Error Failed

This is my current web app structure:

   │   └──
   └── webapp_dir
   │   └──
   │   └──
   │   └──
   │   └──
   └── platforms
       └── platform_one

The file app_one/ imports the platforms/platform_one/ file, but I keep getting a module import error.

app_one/ file import:

from platforms.platform_one import main

Anytime I try and run a method from the app_one/ file through the Python3 shell on the command, by importing the app_one/ file an import module error always occurs when the file imports the platform_one/ file as it says it doesn't exist, even though it does.

I've tried messing around with sys.path, but I want the module to always be able to be imported not just when I add it to sys.path temporarily.

Thank you

What is your working directory when you run the Python 3 shell?