Jinja math problem, HA isn't rounding or converting to a int

Configuration
#1

I’m trying to use the Live Sensor Report Example Automation provided in the Alexa Media Player github wiki.

What I have
The math should use the ‘brightness’ attribute from a light.alexa_virtual and convert it in to a percent integer.

{{ state_attr('light.alexa_virtual', 'brightness') | int / 255 * 100 | int }}

The above is the math part of the conditional:

{% if (state_attr('light.alexa_virtual', 'brightness') | int / 255 * 100 ) | int  == 1  %}
Note

Note: the given example uses states.light.alexa_virtual.attributes.brightness but I changed it to state_attr('light.alexa_virtual', 'brightness').

The math
If state_attr('light.alexa_virtual', 'brightness') = 26
then the result should be 10 right?

 {{ state_attr('light.alexa_virtual', 'brightness') | int / 255 * 100 | int }}
 {{ 26                                              | int / 255 * 100 | int }}

The result should be 10 but when I put it in the Developer Tools > Template editor it shows 10.196078431372548.

What I’ve tried
I’ve tried using round {{ 26 | int / 255 * 100 | round | int }} but that didn’t change anything.

What am I doing wrong?

#2

INT and round only works on the object to the left, so you should try to used more brackets as in your example you rounded 100 and made in INT

{{ (26 | int / 255 * 100) | round(0) | int }}

#3

Or try something like {{ (( float / 255 ) * 100) | int }}

#4

Thank you for explaining that. Adding round(0) fixes it. I’ll send a correction to the yaml to the dev to update their wiki.

Here is the final corrected condition:

{% if (state_attr('light.alexa_virtual', 'brightness') | int / 255 * 100 ) | round(0) | int  == 1  %}

Side question for understanding…
Does | int round using floor?

I ask because…
When I have state_attr('light.alexa_virtual', 'brightness') = 10 without round(0) it comes out to 3, but when I add | round(0) it comes out to the expected 4.

{{ 26 | int / 255 * 100 | int }} = 3 <- Incorrect
{{ 26 | int / 255 * 100 | round(0) | int }} = 4 <- Correct

What does | int do that does not have the expected behavior?

#5

It is Python math that is used, so
Int will round down (floor) to nearest integear, while round(0) will round to nearest integear.

#6

Why have you included the int filter after using round(0) in your template?

| round(0) | int

from here:

{% if (state_attr('light.alexa_virtual', 'brightness') | int / 255 * 100 ) | round(0) | int  == 1  %}

Using round(0) will round the value to an integer so running it through the int filter is redundant.

Screenshot from 2021-02-23 12-39-22

For that matter, the template in the Solution post uses int unnecessarily twice.

{{ (26 | int / 255 * 100) | round(0) | int }}
         ^                             ^
         |                             |
                     Not needed

Screenshot from 2021-02-23 12-51-47

Another example:

Screenshot from 2021-02-23 12-56-56

#7

Hi, what i doing wrong here ? i need intiger ?

11111
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#8

Copy-paste this into the Template Editor and it will report it is a number and the value will not have a any decimal portion (it will be an integer):

{{ (state_attr('climate.hmip_etrv_2_000a1d8997d5e7', 'level') | float(0) * 100) | round(0) | int(0) }}

If you add double-quotes outside of the template, the Template Editor will report it is a string. However, that’s just the way the Template Editor works and doesn’t mean the template’s result will be handled as a string when the template is used elsewhere.

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