title: Python packages and import - no module named xy
body: <p>I'm trying to structure my project like this</p>
  
  <pre><code>app/
  __init__.py
  web/
      __init__.py
      web.py
  database/
      __init__.py
      db.py
  </code></pre>
  
  <p>I just want to import several classes from <code>db.py</code> to <code>web.py</code> but just a <code>ImportError: No module named</code> is thrown. What I tried so far</p>
  
  <p>web.py</p>
  
  <pre><code>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
  </code></pre>
  
  <p>What do I missing? </p>
  
  <p>// edit:</p>
  
  <pre><code>db/__init __.py
  from db import ClassA
  </code></pre>
  
  <p>All other <code>__init__.py</code> are empty. I guess I'm doing something wrong on this.</p>