title: Remove 'u' from a python list
body: <p>I have a python list of list as follows. I want to flatten it to a single list.</p>
  
  <pre><code>l = [u'[190215]']
  </code></pre>
  
  <p>I am trying.</p>
  
  <pre><code>l = [item for value in l for item in value]
  </code></pre>
  
  <p>It turns the list to <code>[u'[', u'1', u'9', u'0', u'2', u'1', u'5', u']']</code></p>
  
  <p>How to remove the <code>u</code> from the list.</p>