Flask da lista aninhada

<ul class="teachers">
  {% for teacher in teachers %}
  <li> <h2> {{ teacher.name }} </h2> 
  <ul>
    {% for x in teacher.name.courses %}
    <li> {{ x }} </li>
  {% endfor %}
  </ul>
  </li>
    {% endfor %}
</ul>
Magnificent Mole