title: Python imports does not work
body: <p>I have such tree:</p>
  
  <pre><code>package/
      subpackage1/
          __init__.py
          impl/
              __init__.py
              moduleA.py
              moduleA_test.py
      subpackage2/
          __init__.py
          impl/
              __init__.py
              moduleB.py
  </code></pre>
  
  <p>In <code>moduleA.py</code> I have this code:</p>
  
  <pre><code>from subpackage2.impl.moduleB import func_abc
  </code></pre>
  
  <p>Module <code>moduleA_test.py</code> just imports <code>moduleA</code> and tests its functions.
  When in terminal if I'm in folder <code>package</code> and run <code>python</code> and then <code>from subpackage1.impl import moduleA</code>, it works normally. </p>
  
  <p>But if I run <code>python submodule1/impl/moduleA_test.py</code> (still in <code>package</code> folder) the code raises an error on the line of the import I wrote above. I get <code>ImportError: No module named subpackage2.impl.moduleB</code>.</p>
  
  <p>I've also tried with <code>python -m submodule1.impl.moduleA_test.py</code> but with no luck.</p>