title: double input and extra letter in list in Sagemath
body: <p>I'm a newbie in python and <a href="http://www.sagemath.org/" rel="nofollow noreferrer">sagemath</a>, so it's confusing me.</p>
  
  <p>with the following code, I've got a <code>u</code> character before each element of the list.</p>
  
  <pre><code>str = raw_input()
  chr = list(str)
  print chr
  
  # input: "alma"
  # output: [u'a', u'l', u'm', u'a']
  </code></pre>
  
  <p>furthermore when I run the project the input field appears twice. first when I have to write, and after it when I press enter (appears with the entered text)</p>
  
  <p><img src="https://i.stack.imgur.com/QK7Sk.png" alt="1"></p>