[SOLVED] How to append items to list using Template?

Configuration
1

Hi! Since one of the latest updates templates can now render lists. However the list workflow seems to be pretty limited. Here’s the problem I faced:
I’m trying to create a sensor with a list of links, parsed via IMTP integration. What I’ve got:

{% set body = state_attr('sensor.avito_clothes_mail', 'body') %}
{% set links = [] %}
{% for i in range(10) %}
    {{ links.append(body | regex_findall_index('https://www.avito.ru.+?(?=")', index = i)) }}
{% endfor %}
{{ links }}

But instead of the wanted list I receive an error: SecurityError: access to attribute 'append' of 'list' object is unsafe.

So here’s my question — how do I create lists using templates, when I’m not allowed to append items to it?

3 Likes
2

You can append items to a list by adding two lists, like this:

{% set data = namespace(numbers=[]) %}
{% for i in range(10) %}
    {% set data.numbers = data.numbers + [i] %}
{% endfor %}
{{ data.numbers }}

For your case, this should work (I cant test it and I am not sure about the “regex_findall_index” stuff):

{% set body = state_attr('sensor.avito_clothes_mail', 'body') %}
{% set data = namespace(links=[]) %}
{% for i in range(10) %}
    {% set data.links = data.links + [(body | regex_findall_index('https://www.avito.ru.+?(?=")', index = i))] %}
{% endfor %}
{{ data.links }}
15 Likes
3

Thank you, that really worked! Seems not obvious at all however :crazy_face:

1 Like
4

Hi @tobi-bo is there a way to set a list item to another value? and remove a specfic item from that list?

{% set data = namespace(numbers=[]) %}
{% set data.numbers = data.numbers + [2] %}
{% set data.numbers = data.numbers + [3] %}
{% set data.numbers[0] =  [2] %}
{{ data.numbers[0] }}

the line where i try to set value [0] from the list, does not work, however displaying only value[0] as in the last line, is no problem.

On the second problem, removing one item from the list, i assume you have to create a new list entirely with the remaining list items…

Thanks in advance!

1 Like
5

Thank you!
I guess this is an effective way to limit issues around mutability so I kind of get why they force you to do it that way

6

I’ve been trying to manipulate a list using that approach, but cannot get it to work. It must be a scoping issue, but apart from the condition, I cannot see my code being any different from the example above.

{% set list = ['A', 'B', 'C', 'D', 'E'] %}
{% set prefixed_list = [] %}
{% for item in list %}
  {% if item == "C" %}
    {{ item }}
    {% set prefixed_list = prefixed_list + [item] %}
    {{ prefixed_list }}
  {% else %}
    {{ item }}
    {% set prefixed_list = prefixed_list + ['the ' + item] %}
    {{ prefixed_list }}
  {% endif %}
{% endfor %}
{% set list = prefixed_list %}
{{ list }}

This returns:

A
['the A']

B
['the B']

C
['C']

D
['the D']

E
['the E']

[]
7

Yeah, thats a scoping issue, therefore you need the namespace(prefixed_list=[])

{% set list = ['A', 'B', 'C', 'D', 'E'] %}
{% set data = namespace(prefixed_list=[]) %}
{% for item in list %}
  {% if item == "C" %}
    {{ item }}
    {% set data.prefixed_list = data.prefixed_list + [item] %}
    {{ data.prefixed_list }}
  {% else %}
    {{ item }}
    {% set data.prefixed_list = data.prefixed_list + ['the ' + item] %}
    {{ data.prefixed_list }}
  {% endif %}
{% endfor %}
{% set list = data.prefixed_list %}
{{ list }}
1 Like
8

Thanks a lot that solved it!

9

If you’re interested, the same result, prepending the word the to all letters except the letter C, can be achieved using regex_replace.

{{ ['A', 'B', 'C', 'D', 'E']
  | map('regex_replace', '([^C])', 'the \\1') | list  }}

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10

I’m struggling to understand, perhaps because I am so new to templating…
What I’m trying to do is average a list of numbers together, but there are times when they are “unavailable”.

How do I create a list and add the resulting value only if it is a number and then ultimately average those? Sometimes it will be 3 values getting averaged, sometimes 2 and rarely 1.

Is this possible?

This is the base of what I have come up with thus far that works when all three are available, but as soon as one is unavailable it breaks for obvious reasons.

{% if is_number(states('sensor.first_oil')) %}
  {% set first = states('sensor.first_oil')|float %}
  {% elif set %}
  {% endif %}

{% if is_number(states('sensor.second_oil')) %}
  {% set second = states('sensor.second_oil')|float %}
  {% endif %}

{% if is_number(states('sensor.third_oil')) %}
  {% set third = states('sensor.third_oil')|float %}
  {% endif %}


{{average(first,second,third)}}

Thank you!

11

Have you tried the min/max helper ? It looks like it will ignore unknown entities in the calculation (except sum)

12

Use the select() filter to remove unavailable entities… there’s no need to use all those if statements:

{{ ['sensor.first_oil', 'sensor.second_oil', 'sensor.third_oil'] 
| select('has_value') | expand 
| map(attribute='state') | map('float') | average }}
13

I can’t believe it as how simple this is, but I believe this worked. I don’t even need to make a template sensor :joy:
Thank you!

14

That’s so simple too, I wish I came here before spending like 6 hours trying to make this work LOL.
I love to learn so I want to fool around with this to see how it works as it’s so much simpler.
Thank you!!

1 Like