String concatenation in Jinja

Question

I just want to loop through an existing list and make a comma delimited string out of it.
Something like this: my_string = \'stuff, stuff, stuff, stuff\'

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Answer 1

If stuffs is a list of strings, just this would work:

{{ stuffs|join(", ") }}

Link to join filter documentation, link to filters in general documentation.

Answer 2

You can use + if you know all the values are strings. Jinja also provides the ~ operator, which will ensure all values are converted to string first.

{% set my_string = my_string ~ stuff ~ ', '%}

Answer 3

Just another hack can be like this.

I have Array of strings which I need to concatenate. So I added that array into dictionary and then used it inside for loop which worked.

{% set dict1 = {'e':''} %}
{% for i in list1 %}
{% if dict1.update({'e':dict1.e+":"+i+"/"+i}) %} {% endif %}
{% endfor %}
{% set layer_string = dict1['e'] %}

Answer 4

If you can't just use filter join but need to perform some operations on the array's entry:

{% for entry in array %}
User {{ entry.attribute1 }} has id {{ entry.attribute2 }}
{% if not loop.last %}, {% endif %}
{% endfor %}

Answer 5

My bad, in trying to simplify it, I went too far, actually stuffs is a record of all kinds of info, I just want the id in it.

stuffs = [[123, first, last], [456, first, last]]

I want my_sting to be

my_sting = '123, 456'

My original code should have looked like this:

{% set my_string = '' %}
{% for stuff in stuffs %}
{% set my_string = my_string + stuff.id + ', '%}
{% endfor%}

Thinking about it, stuffs is probably a dictionary, but you get the gist.

Yes I found the join filter, and was going to approach it like this:

 {% set my_string = [] %}
 {% for stuff in stuffs %}
 {% do my_string.append(stuff.id) %}
 {% endfor%}
 {%  my_string|join(', ') %}

But the append doesn't work without importing the extensions to do it, and reading that documentation gave me a headache. It doesn't explicitly say where to import it from or even where you would put the import statement, so I figured finding a way to concat would be the lesser of the two evils.