title: Python function return 2 lists
body: <p>I have a function that creates two lists. I want the function to return the two lists as <code>[], []</code>.</p>
  
  <p>Here is the code. This returns a list that look like this <code>[[], []]</code>, close but still not what I want.</p>
  
  <pre><code>def create_xy_lst(start, length, step, up, down):
      new_list = []
      new_list.append(create_x_lst(start, length, step))
      new_list.append(create_y_lst(start, length, up, down))
      return new_list
  </code></pre>
  
  <p>Then I tried a different approach. This returns <code>([], [])</code> which is a tuple.</p>
  
  <pre><code>def create_xy_lst(start, length, step, up, down):
  
      x = (create_x_lst(start, length, step))
      y = (create_y_lst(start, length, up, down))
      return x, y
  </code></pre>
  
  <p>How can I make the function return <code>[], []</code>?</p>
  
  <p>Python 2.7</p>