title: using map function to square a list
body: <p>I have a list which I want to square each of them.</p>
  
  <p>this is what I have done</p>
  
  <pre><code>def square(x):
      return x*x
  
  numbers = [1,2,3,4,5,6]
  squares = map(square, numbers)
  
  
  squares_as_strings = str(squares)
  
  
  print(','.join(squares_as_strings))
  </code></pre>
  
  <p>but the answer is this</p>
  
  <pre><code>[,1,,, ,4,,, ,9,,, ,1,6,,, ,2,5,,, ,3,6,]
  </code></pre>
  
  <p>instead of </p>
  
  <pre><code>[1,4,9,16,25,36]
  </code></pre>