datasette/datasette/templates/_table.html

<table class="rows-and-columns">
    <thead>
        <tr>
            {% for column in display_columns %}
                <th class="col-{{ column.name|to_css_class }}" scope="col">
                    {% if not column.sortable %}
                        {{ column.name }}
                    {% else %}
                        {% if column.name == sort %}
                            <a href="{{ path_with_replaced_args(request, {'_sort_desc': column.name, '_sort': None, '_next': None}) }}" rel="nofollow">{{ column.name }}&nbsp;▼</a>
                        {% else %}
                            <a href="{{ path_with_replaced_args(request, {'_sort': column.name, '_sort_desc': None, '_next': None}) }}" rel="nofollow">{{ column.name }}{% if column.name == sort_desc %}&nbsp;▲{% endif %}</a>
                        {% endif %}
                    {% endif %}
                </th>
            {% endfor %}
        </tr>
    </thead>
    <tbody>
    {% for row in display_rows %}
        <tr>
            {% for cell in row %}
                <td class="col-{{ cell.column|to_css_class }}">{{ cell.value }}</td>
            {% endfor %}
        </tr>
    {% endfor %}
    </tbody>
</table>