title: Import a file from another directory
body: <p>I have a file call <code>entryPoint.py</code> : </p>
  
  <pre><code>from .commonLib.deviceLib import *
  </code></pre>
  
  <p>And I have a file called <code>deviceLib.py</code> :</p>
  
  <pre><code>import math
  import sys
  import logging
  import requests
  import this
  
  class DeviceLib(object):
      def __init__(self, connectionDb):
          self.__db = connectionDb
  </code></pre>
  
  <p>The tree is like this : </p>
  
  <pre><code>/test
      entryPoint.py
  /commonLib
      __init__.py
      deviceLib.py
  </code></pre>
  
  <p>When I execute <code>python entryPoint.py</code> I get the error : <code>Attempted relative import in non-package</code>. Please help me.</p>