title: Adding elements to python generators
body: <p>Is it possible to append elements to a python generator?</p>
  
  <p>I'm currently trying to get all images from a set of disorganized folders and write them to a new directory. To get the files, I'm using os.walk() which returns a list of image files in a single directory. While I can make a generator out of this single list, I don't know how to combine all these lists into one single generator. Any help would be much appreciated.</p>
  
  <p>Related:</p>
  
  <ul>
  <li><a href="https://stackoverflow.com/questions/406121/flattening-a-shallow-list-in-python">Flattening a shallow list in python</a></li>
  </ul>