title: python import root folder and use all subfolders
body: <p>With the following dir structure</p>
  
  <pre><code>.
  ├── setup.py
  └── yourpackage
      ├── __init__.py
      ├── some_module.py
      ├── other_module.py
      └── sub_package
          ├── __init__.py
          └── more_modules.py
  </code></pre>
  
  <p>Is it possible to do this:</p>
  
  <pre><code>&gt;&gt; import yourpackage as yp
  &gt;&gt; yp.some_module.bar()
  &gt;&gt; yp.sub_package.more_modules.foo()
  </code></pre>
  
  <p>where the contents of <code>some_module</code> is</p>
  
  <pre><code>def bar(): print('bar')
  </code></pre>
  
  <p>where the contents of <code>more_modules</code> is</p>
  
  <pre><code>def foo(): print('foo')
  </code></pre>
  
  <p>I can't seem to get this to work</p>
  
  <p>EDIT: The error I would get in the first case is</p>
  
  <pre><code>Traceback (most recent call last):
    File "&lt;string&gt;", line 1, in &lt;module&gt;
  AttributeError: module 'yourpackage' has no attribute 'some_module'
  </code></pre>
  
  <p>In the second case, it's a similar error, but with <code>more_modules</code></p>