title: defaultdict : first argument must be callable or None
body: <p>I ran the following code :</p>
  
  <pre><code>from collections import defaultdict
  lst = list(range(0,5))
  d = defaultdict(lst)
  </code></pre>
  
  <p>and I got this error : </p>
  
  <pre><code>TypeError: first argument must be callable or None
  </code></pre>
  
  <p>Please help</p>