How do I show a block in a region?

Question

All blocks in the footer region use a CSS grid system. I want to add a <div> with CSS attributes to each (custom) block in the footer. The code I have will show the blocks in the footer, but will give an error. Changing {{ key }} to {{ key.content }} is not helping. I am using Drupal 8.6.8.

The code that I am using in the page.html.twig template is the following.

{% for key in page.footer %}
    <div class="col col-4">
        {{ key }}
    </div>
{% endfor %}

Using that code, I get this error message.

User error: "0" is an invalid render array key in Drupal\Core\Render\Element::children() (line 97 of core\lib\Drupal\Core\Render\Element.php).

Answer 1

Remove array keys starting with '#':

{% for key, block in page.footer if key|first != '#' %}
    <div class="col col-4">
        {{ block }}
    </div>
{% endfor %}