title: Module not found running on command line
body: <p>I have the following project structure:</p>
  
  <pre><code>project/
      example/
          __init__.py
          foo.py
          boo.py
          meh.py
      tests/
          example/
              test_foo.py
              test_boo.py
              test_meh.py
  </code></pre>
  
  <p>As example, I'm importing <code>foo.py</code> in <code>boo.py</code> as <code>import example.foo as f</code>. And I'm running tests with <code>python3 -m pytest -s -v --cov tests</code> on root folder (project). The unit tests are running very smooth but when I try to run a single file as <code>python3 example/boo.py</code> I got an error:</p>
  
  <pre><code>ModuleNotFoundError: No module named 'example'
  </code></pre>