title: Python error "ImportError: No module named"
body: <p>Python is installed in a local directory.  </p>
  
  <p>My directory tree looks like this:</p>
  
  <pre><code>(local directory)/site-packages/toolkit/interface.py
  </code></pre>
  
  <p>My code is in here:</p>
  
  <pre><code>(local directory)/site-packages/toolkit/examples/mountain.py
  </code></pre>
  
  <p>To run the example, I write <code>python mountain.py</code>, and in the code I have:</p>
  
  <pre><code>from toolkit.interface import interface
  </code></pre>
  
  <p>And I get the error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "mountain.py", line 28, in ?
      from toolkit.interface import interface
  ImportError: No module named toolkit.interface
  </code></pre>
  
  <p>I have already checked <code>sys.path</code> and there I have the directory <code>/site-packages</code>. Also, I have the file <code>__init__.py.bin</code> in the toolkit folder to indicate to Python that this is a package. I also have a <code>__init__.py.bin</code> in the examples directory.</p>
  
  <p>I do not know why Python cannot find the file when it is in <code>sys.path</code>.  Any ideas?  Can it be a permissions problem?  Do I need some execution permission?</p>