title: max in python - error missing 1 required positional argument: 'b'
body: <p>I am trying to do one exercise on python (my version is python33
  The exercise reads:</p>
  
  <blockquote>
    <p>Write a function find_longest_word1() that takes a list of words and returns the length of the longest one. Use only higher order functions.</p>
  </blockquote>
  
  <p>My attempt is:</p>
  
  <pre><code>def find_longest_word1(a):
      out = max(list(map(len,a)))
      print (out)
  find_longest_word1(["This","is","a","listing"])
  </code></pre>
  
  <p>The error which I get is:</p>
  
  <pre><code>max() missing 1 required positional argument 'b'
  </code></pre>
  
  <p>I have passed one list as argument. Do I need to give some other argument to max function ?</p>