title: How to generate directory size recursively in python, like du . does?
body: <p>Lets say my structure is like this</p>
  
  <pre><code>/-- am here
  /one/some/dir
  /two
  /three/has/many/leaves
  /hello/world
  </code></pre>
  
  <p>and say /one/some/dir contains a big file, 500mb, and /three/has/many/leaves contains a 400mb file in each folder.</p>
  
  <p>I want to generate the size for each directory, to have this output</p>
  
  <pre><code>/ - in total for all
  /one/some/dir 500mb
  /two 0 
  /three/has/many/leaved - 400mb
  /three/has/many 800
  /three/has/ 800+someotherbigfilehere
  </code></pre>
  
  <p>How would I go about this?</p>