{% for host_name, host_details in hosts | dictsort -%}
{{ host_name }}
{% endfor %}

{% for group_name, group_details in groups | dictsort -%}
[{{ group_name }}]
{% for host in group_details.get("hosts", []) -%}
{{ host }}
{% endfor %}
{% endfor %}
{% for group_name, group_details in groups | dictsort -%}{% if group_details.get("children", []) %}[{{ group_name }}:children]
{% endif -%}
{% for child in group_details.get("children", []) -%}
{{ child }}
{% endfor %}
{% endfor %}