CODEWITHSUNDEEP
pythonflaskjinja2template-engine
Mittenchops
Mittenchops

Reputation: 19674

Jinja2 round filter not rounding

I have the following code in my template:

data: [{% for deet in deets %} {{ deet.value*100|round(1) }}{% if not loop.last %},{% endif %} {% endfor %}]

I am expecting data rounded to 1 decimal place. However, when I view the page or source, this is the output I'm getting:

data: [ 44.2765833818,  44.2765833818,  44.2765833818,  44.2765833818,  44.2765833818,  44.2765833818,  44.2765833818,  44.2765833818,  44.2765833818,  44.2765833818 ]

This is not rounded to 1 decimal place. It runs without a template error or anything, but produces incorrect output. My understanding from the documentation, and even a related stack overflow question, are that my format should work. What am I missing or doing wrong?

Upvotes: 36

Views: 53583

Answers (5)

Denis Shulyaka
Denis Shulyaka

Reputation: 89

If filter operator has precedence, then you should use round(3) instead of round(1) in "{{ 100*deet.value|round(1) }}"

Upvotes: 2

Dixon MD
Dixon MD

Reputation: 188

Try this

{{ (deet.value*100)|round(1) }}

If we didn't put parenthesis, round will do only to 100 not to the result.

Upvotes: 8

Dan Garthwaite
Dan Garthwaite

Reputation: 3526

I ran across this... needed int(mem_total / 4) in jinja. I solved it by making it two operations:

{% set LS_HEAP_SIZE = grains['mem_total'] / 4 %}
{% set LS_HEAP_SIZE = LS_HEAP_SIZE | round | int %}

Upvotes: 3

John R
John R

Reputation: 753

You can put parens around the value that you want to round. (This works for division as well, contrary to what @sobri wrote.)

{{ (deet.value/100)|round }}

NOTE: round returns a float so if you really want the int you have to pass the value through that filter as well.

{{ (deet.value/100)|round|int }}

Upvotes: 59

Mittenchops
Mittenchops

Reputation: 19674

Didn't realize the filter operator had precedence over multiplication!

Following up on bernie's comment, I switched

{{ deet.value*100|round(1) }}

to

{{ 100*deet.value|round(1) }}

which solved the problem. I agree the processing should happen in the code elsewhere, and that would be better practice.

Upvotes: 43

Related Questions