title: Python3 subprocess communicate example
body: <p>I'm new to subprocessing.</p>
  
  <p>I just need a really simple win32 example of communicate() between a <strong>parent.py</strong> and <strong>child.py</strong>. A string sent from parent.py to child.py, altered by child.py and sent back to parent.py for print() from parent.py.
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  I'm posting this because examples I have found end up either not being win32 or not using a child which just confuses me.</p>
  
  <p>Thanks for you help.</p>