Group items by attribute: groupby

The groupby filter groups items in a list by a common attribute, producing a list of (grouper, list) pairs where grouper is the attribute value and list contains all items that share that value.

This is extremely useful when you want to organize entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] by a shared property. For example, you can group lights by their area, sensors by their state, or devices by their manufacturer. The result lets you iterate over each group and display or process the items together. It works especially well with expand to organize large collections of entities into meaningful categories.

Usage

Here’s how to use this template function. Copy any example and adjust it to your setup.

{% for state, entities in expand("group.all_lights") | groupby("state") %}
  {{ state }}: {{ entities | map(attribute="entity_id") | join(", ") }}
{% endfor %}

off: light.bedroom, light.garage
on: light.kitchen, light.living_room

Function signature

The signature is a technical summary of this template function. It shows the name of the function, the values (called parameters) it accepts, and what type of data each parameter expects (for example, a piece of text or a number).

Function parameters that have a = with a value after them are optional. If you leave them out, the default value shown is used automatically. Function parameters without a default are required.

groupby(
    value: list,
    attribute: str,
    default: Any = None,
) -> list[tuple]

Function parameters

The following parameters can be provided to this filter.

Grouping with dotted attributes

Use dotted notation to group by nested attributes.

{% for device_class, entities in expand("group.all_sensors")
  | groupby("attributes.device_class") %}
  {{ device_class }}: {{ entities | length }} sensors
{% endfor %}

humidity: 3 sensors
temperature: 5 sensors

Default value for missing attributes

Use the default parameter to include items that lack the grouping attribute.

{% for area, entities in expand("group.all_lights")
  | groupby("attributes.area", default="Unknown") %}
  {{ area }}: {{ entities | map(attribute="entity_id") | join(", ") }}
{% endfor %}

Kitchen: light.kitchen_ceiling, light.kitchen_counter
Living room: light.living_room_main
Unknown: light.unnamed_bulb

Good to know

• The input must be sorted by the grouping attribute already. This filter only groups adjacent items with matching values.
• Items without the attribute are dropped unless you supply a default.
• Returns a list of (grouper, items) tuples, which you unpack in a for loop.

Try it yourself

Ready to test this? Open Developer tools > Template, paste the example into the Template editor, and watch the result update on the right. Edit the values to see how the function adapts to your own entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more].

More examples

Real scenarios where this function comes up in automations and templates. Copy any example and adapt it to your setup.

Group entities by state

Group all entities in a group by their current state value.

{% for state, entities in expand("group.all_lights") | groupby("state") %}
  {{ state | upper }}: {{ entities | map(attribute="name") | join(", ") }}
{% endfor %}

OFF: Bedroom light, Garage light
ON: Kitchen light, Living room light

Count entities per group

Show a summary of how many entities are in each group.

{% for state, entities in expand("group.all_lights") | groupby("state") %}
  {{ entities | length }} light(s) are {{ state }}
{% endfor %}

2 light(s) are off
2 light(s) are on

Group sensors by area and find averages

Group temperature sensors by their area and calculate the average for each.

{% for area, sensors in expand("group.temperature_sensors")
  | groupby("attributes.area") %}
  {{ area }}: {{ sensors | map(attribute="state") | map("float")
     | average | round(1) }}°C
{% endfor %}

Bedroom: 19.8°C
Kitchen: 22.1°C
Living room: 21.3°C

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with your template and expected result, or share on our subreddit /r/homeassistant.

Related template functions

These functions work well alongside this one:

• Sort a list: sort - Sorts the items in a list, with optional attribute-based and reverse sorting.

• Filter items by attribute test: selectattr - Filters a list, keeping only items where a specified attribute passes a test.

• Transform list items: map - Applies a filter to each item or extracts an attribute from each item in a list.

• Remove duplicate values: unique - Removes duplicate values from a list, keeping only unique items.