title: Problem in sorting a list converted from tuple
body: <p>I am writing a program to take a list of words from the user, remove the repeated words and then print the output after sorting the words. However, I ran into this issue while sorting:</p>
  <pre><code>a = set(input('Words: ').split(' '))
  b = list(a).sort()
  
  print(b)
  </code></pre>
  <p>The terminal prints 'None' as the result of the code, but in this case:</p>
  <pre><code>a = set(input('Words: ').split(' '))
  b = list(a)
  b.sort()
  print(b)
  </code></pre>
  <p>It gives the right output. Why is this so?</p>