title: 'collections.defaultdict' object has no attribute 'append'
body: <p>I encountered a problem with a code snippet that I'm trying to use. Here is the code:</p>
  
  <pre><code>from collections import defaultdict
  from string import ascii_lowercase
  words = defaultdict(list)
  with open('/usr/share/dict/words') as fin:
      for word in fin:
          if len(word) == 5: 
               words.append(word)
  </code></pre>
  
  <p>Whenever I try to run the code it returns the error:</p>
  
  <pre><code>AttributeError: type object 'collections.defaultdict' has no attribute 'append'
  </code></pre>
  
  <p>Any suggestions?</p>