[Django]-Junk after document element: line 13, column 2

You do not have a single root element. Try adding a parent above each of your book elements. Maybe books?

<books>
  <book> ... </book>
  <book> ... </book>
</books>

If that does not help try looking at line 13, col 2 like the error message suggests.

bad_line = xmlDocData.splitlines()[12]