title: How to append an element of a sublist in python
body: <p>I have a list of lists in the form:</p>
  
  <pre><code>list = [[3, 1], [3, 2], [3, 3]]
  </code></pre>
  
  <p>And I want to split it into two lists, one with the x values of each sublist and one with the y values of each sublist.   </p>
  
  <p>I currently have this:</p>
  
  <pre><code>x = y = []
  for sublist in list:
      x.append(sublist[0])
      y.append(sublist[1])
  </code></pre>
  
  <p>But that returns this, and I don't know why:</p>
  
  <pre><code>x = [3, 1, 3, 2, 3, 3]
  y = [3, 1, 3, 2, 3, 3]
  </code></pre>