title: My module has __init__.py and still Python can't import it
body: <p>I have a small python module </p>
  
  <pre><code>+-- address_book
  |   +-- models.py
  |   +-- __init__.py 
      +-- test
      |   +-- test_models.py 
  </code></pre>
  
  <p>When I run <code>python address_book/test/test_models.py</code> I get this error </p>
  
  <pre><code>Traceback (most recent call last):
    File "address_book/test/test_models.py", line 5, in &lt;module&gt;
      from address_book import models
  ImportError: No module named 'address_book'
  </code></pre>
  
  <h1>test_models.py</h1>
  
  <pre><code>#!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  import unittest
  from address_book import models
  ...
  ...
  ...
  if __name__ == '__main__':
      unittest.main()
  </code></pre>