title: In hash tables, how can iteration over keys be implemented?
body: <p>Basically, I wonder what happens or might happen under the hood when I run something like this:</p>
  <pre class="lang-py prettyprint-override"><code>for key in some_hash_map.keys():
      print(key)
  </code></pre>
  <p>Is it just about using a reversed hash function?</p>