Combine iterables: zip

The zip template function combines two or more lists (or other collections) element by element, producing a list of tuples where each tuple contains one item from each input list. It works just like Python’s built-in zip() function. If the lists are different lengths, the result is truncated to the length of the shortest list.

This is useful when you have related data in separate lists that you need to pair up. For example, you might have a list of room names and a list of temperature readings, and you want to combine them so each room is paired with its temperature. Or you might want to iterate over two lists in parallel to build a formatted output.

Usage

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

{{ zip(["a", "b", "c"], [1, 2, 3]) | list }}

[('a', 1), ('b', 2), ('c', 3)]

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 = are usually required. A few optional parameters have no default value, so the signature shows them without a = as well. To check whether a parameter is required, look at the parameter list below the signature. Each parameter is marked as Required or Optional.

The most common optional parameter without a default value is default. The default parameter sets the value a function returns when the function can’t produce a result, for example, when float gets text that isn’t a number. If you leave out default, there is no fallback value, so most functions raise an error and the template fails. The parameter list of each function says what happens. If you set default, the function returns your value instead.

round(
    value: Any,
    precision: int = 0,
    method: str = "common",
    default: Any,
) -> float | int | Any

zip(
    *iterables: Iterable,
) -> list[tuple]

Function parameters

The following parameters can be provided to this function.

Pairing related data

When you have data split across multiple lists, zip brings them together.

{% set rooms = ["Living room", "Bedroom", "Kitchen"] %}
{% set temps = [21.5, 19.8, 22.3] %}
{% for room, temp in zip(rooms, temps) %}
  {{ room }}: {{ temp }}°C
{% endfor %}

Living room: 21.5°C
Bedroom: 19.8°C
Kitchen: 22.3°C

Unequal length lists

When lists have different lengths, zip stops at the shortest one.

{{ zip([1, 2, 3], ["a", "b"]) | list }}

[(1, 'a'), (2, 'b')]

Good to know

• Returns an iterator. Pipe the result through list if you need to reuse it or display it directly.
• Input lists of different lengths are silently truncated to the shortest. Extra items from the longer lists are dropped without warning.

Try it yourself

Ready to test this? Open Settings > 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.

Build a formatted summary

Combine entity names with their states to create a summary string.

{% set names = ["Front door", "Back door", "Garage"] %}
{% set statuses = ["closed", "open", "closed"] %}
{% for name, status in zip(names, statuses) %}
  {{ name }} is {{ status }}
{% endfor %}

Front door is closed
Back door is open
Garage is closed

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:

• Merge dictionaries: combine - Merges multiple dictionaries into one.