title: How to import my own modules the elegant way?
body: <p>I am struggling with a dummy question about importing classes from another sub-directory and I can’t find satisfying solution. Here is the context: I have a root folder, let’s call it project, that contains two sub folders, called app and test. </p>
  
  <p>In app, I have my classes files, class1.py and so on. In test, I have test_class1.py to hold my unit test class. Seems to be some standard folder structure to me. How do I import class1 from test_class1.py? So far I append ‘../app’ to my sys.path but it looks so ugly to me! I tried <code>from ..app import class1</code> and so many other combinations unsuccessfully.</p>
  
  <p>Second question: Are <code>__init__.py</code> still needed in python 3.6+?
  Thanks for your help</p>