{% set services_by_cat = {} %}
{% for s in services %}
{% set cat = s.category if s.category else "__none__" %}
{% set _ = services_by_cat.setdefault(cat, []).append(s) %}
{% endfor %}
{% for cat, cat_services in services_by_cat.items() %}
{% if cat != "__none__" %}
{{ cat }}
{% endif %}
{% for service in cat_services %}
{{ service.name }}
{% for ping in uptime[service.name] %}
{% if ping == "I" %}
{% elif ping == "O" %}
{% else %}
{% endif %}
{% endfor %}