Python packages and import - no module named xy

Question

I'm trying to structure my project like this

app/
__init__.py
web/
    __init__.py
    web.py
database/
    __init__.py
    db.py

I just want to import several classes from db.py to web.py but just a ImportError: No module named is thrown. What I tried so far

web.py

from __future__ import absolute_import
    from database.db import ClassA
OR

from __future__ import absolute_import
from app.database.db import ClassA

OR

from __future__ import absolute_import
import database import ClassA

What do I missing?

// edit:

db/__init __.py
from db import ClassA

All other __init__.py are empty. I guess I'm doing something wrong on this.

Answer 1

It should be

from ..database import db

You can also check the importings by running the web.py from the root of your project

python -m app.web.web

Answer 2

Assuming:

C:\pytest\
   test.py
   \database\
       db.py
       __init__.py
   \subfolder\
       __init__.py
       coolios.py

where __init__.py contains:

from db import *

and the second __init__.py contains:

from coolios import *

and db.py contains:

class WHAM():
    def __init__(self):
        print 'You import me!'

and coolios.py contains:

from database import *

class ganster():
    def __init__(self):
        WHAM()

and test.py contains:

from subfolder import ganster
ganster()

It should work.