My life with python is just started. I am clueless about how to organize folders in python(flask)

My intention is to organize my application in following directory/file structure

src[![enter image description here](https://i.stack.imgur.com/ZCYzn.png)](https://i.stack.imgur.com/ZCYzn.png)

`server.py` is the main file

`database.py` holding DB related sharable resources

`customer.py` is a simple python class which need DB instance from `database.py`

```
from ....shared.database import DB # How to solve this

class Customer():
    def __init__(self):
        self._first_name="John"

```

but I am getting an error `Attempted relative import beyond top-level package`

How do I make this works?!.

folder strucure representation

```
src
  app
    /modules
         /customers
              /models
                 customer.py
    /shared
       /database.py
  /server.py

```