index.html

{% extends "app.html" %}
{% block content %}
<a href="{% url action="new" %}">
  New
</a>

<table>
  {% for pet in pets %}
    <tr>
      <td>{{ pet.name }}</td>
      <td>{{ pet.species }}</td>
      <td>
        <a href="{% url action="edit"
                        id=pet.id %}">
          Edit
        </a>
      </td>
    </tr>
  {% endfor %}
</table>
{% endblock %}