title: Object of type 'map' has no len() in Python 3
body: <p>I have a problem with Python 3. I got Python 2.7 code and at the moment I am trying to update it. I get the error:</p>
  
  <blockquote>
    <p>TypeError: object of type 'map' has no len()</p>
  </blockquote>
  
  <p>at this part:</p>
  
  <pre><code>str(len(seed_candidates))
  </code></pre>
  
  <p>Before I initialized it like this:</p>
  
  <pre><code>seed_candidates = map(modify_word, wordlist)
  </code></pre>
  
  <p>So, can someone explain me what I have to do?</p>
  
  <p>(EDIT: Previously this code example was wrong because it used <code>set</code> instead of <code>map</code>. It has been updated now.)</p>