% if data is not UNDEFINED and isinstance(data, list):
<table>
  % for idx, elem in enumerate(data):
  <%
      if idx % 2 == 0:
          color = "lighter"
      else:
          color = "darker"
  %> <tr><td class="${color}">${elem}</td></tr>
  % endfor
</table>
% elif data is not UNDEFINED:
<p>${data}</p>
% else:
<p>No data available</p>
% endif