title: Calling a function from a module on a submodule
body: <p>I'm quite new to working with more complex modules, but I think is about time to implement them in my work flow. Also, I don't come from a software engineering background so some of my languages might be inaccurate, please bear with me. My module folder structure is like this:</p>
  
  <pre><code>+-- module_name
  |   +-- ml.py
  |   +-- exp_an.py
  |   +-- plotting.py
  +-- etl
  |   +-- machine_learning.py
  |   +-- data_manipulation.py
  </code></pre>
  
  <p>The reason I have two folders is because the scripts directly on <code>module_name</code> are our personal library for use on most projects and the <code>etl</code> has code that is specific to this project.</p>
  
  <p>In the beginning I had both folders on the same directory but I was having trouble importing from <code>module_name</code> to <code>etl</code>.</p>
  
  <p>The thing is, in <code>machine_learning.py</code> I want to call a function from <code>ml.py</code>. I tried doing:</p>
  
  <pre><code>import sys
  sys.append('../')
  import module_name as mn
  </code></pre>
  
  <p>But this seems to bring some recursivity issues, because when I try to call mn.ml I get a <code>mn has no attribute called ml</code> error.</p>
  
  <p>So, my question is, what is the right way to do this? Let's say I want to call a function called <code>transform()</code> that is inside <code>ml.py</code> in my <code>machine_learning.py</code> script. Is there a way to do this? Is there a better way to do this? Thanks</p>