Returning dictionary from a template sensor

Configuration
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1

Hi,

I’m wondering what would be the correct syntax/method for returning a dictionary from a template sensor. I have a template sensor code calculating multiple values which would be of interest in the UI and I would not want to duplicate the phases where calculus is being done and just return single state but a dictionary with multiple keys.

So, I have a sensor in my templates.yaml specifying the sensor, here’s a simplified version:

    - name: "dict_sensor"
      icon: mdi:exponent-box
      unique_id: 1fc4c3c2-d5e9-400b-897b-31b5260249f4
      state: |
        {% set result = [
          ("value", 1),
          ("something", 2)
          ]
        %}
        {{ dict.from_keys(result) }}

In Developer Tools → Template editor I can test this sensor output and the problem is the result is not being recognized as a dictionary properly even if the result window shows the result type being parsed as a dict. Also, if creating the same dictionary locally in the template editor it works just fine:

{# Get dictionary from sensor #}
{% set from_sensor = states('sensor.dict_sensor') %}
{{ from_sensor }}
{{ from_sensor.value }}

{# Create dictionary locally #}
{% set result = [
  ("value", 1),
  ("something", 2)
  ]
%}
{% set local_dict = dict.from_keys(result) %}
{{ local_dict }}
{{ local_dict.value }}

…produces output of:

'str object' has no attribute 'value'
{'value': 1, 'something': 2}





{'value': 1, 'something': 2}
1
Result type: string

This template listens for the following state changed events:

Entity: sensor.dict_sensor

So, the dict coming from sensor has no attribute “value”. The dictionary defined locally has it. What is the correct way to do this with dictionaries?

Thanks!

2

Every entity’s state value is handled as a string.

An entity’s state value may look like a boolean, number, list, dict, etc but it’s ultimately a string.

Try this:

{# Get dictionary from sensor #}
{% set from_sensor = states('sensor.dict_sensor') | from_json %}
{{ from_sensor.value }}

EDIT

Remove dict function from the Template Sensor.

3

Your clarification the return value is actually a string solved it! However, It seems we cannot convert returned dict from the sensor with from_json filter as suggested (ends up with vJSONDecodeError: unexpected character: line 1 column 2 (char 1) error as dictionary is not properly formatted as JSON.

I ended up converting the template sensor to output a JSON string like this:

    - name: "dict_sensor"
      icon: mdi:exponent-box
      unique_id: 1fc4c3c2-d5e9-400b-897b-31b5260249f4
      state: >
        {% set result = '{
          "value":"1",
          "something":"2"}' 
        %}
        {{ result  }}

Values need to be strings in quotes. After this the template editor shows:

{% set json_from_sensor = states('sensor.dict_sensor') | from_json %}
{{ json_from_sensor }}
{{ json_from_sensor.value }}

and result is

{'value': '1', 'something': '2'}
1
Result type: string

This template listens for the following state changed events:

Entity: sensor.dict_sensor

Thanks a lot!

4

I forgot to mention to remove the dict function from the Template Sensor’s template (because it produces a python dict object which cannot be converted with from_json). Anyways, you discovered that part by yourself.