import module in different contexts

I have a file structure like this:

work/
├─ analysis.ipynb
├─ app/
│  ├─ __init__.py
│  ├─ class_a.py
│  ├─ script.py
│  ├─ utils.py

File class_a.py contains a class MyClass and also an import from utils like this:

from utils import useful_function

class MyClass():
    ...

Then I try to import MyClass in analysis.ipynb like this:

from app.class_a import MyClass

and get an error:

ModuleNotFoundError                       Traceback (most recent call last)
<ipython-input-4-8eeb8559d767> in <module>
      2 import os
      3 from datetime import datetime
----> 4 from app.class_a import MyClass
      5 from app.utils import useful_function
      6 ...

~/Documents/work/app/class_a.py in <module>
      1 import pandas as pd
----> 2 from utils import useful_function
      3 
      4 class MyClass():
      5     '''indeed very necessary class for me

ModuleNotFoundError: No module named 'utils'

I have figured out that if I change all imports in app folder to something like this:

from app.utils import useful_function

Then I can import all I need from analysis.ipynb

However app should work as something I run with python script.py and that does not work unless imports are written in the original way.

I do not understand modules and packaging and so can not even ask a question precisely, but how do I align import "styles" in order to both be able to run python scripts.py from the app directory and import MyClass from analys.ipynb?

Solution

import statements search through the list of paths in sys.path, so I've added these lines to my analysis.ipynb:

import sys
sys.path.append('/path/to/work/app/')

In case someone would have the same question and struggle as me.