String concatenation in Jinja

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'

I already know about loop.last, I just need to know how to make the third line in my code below WORK.

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

Solution 1:

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

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

See join filter documentation, as well as filters in general documentation.

p.s.

More reader friendly way

{{ my ~ ', ' ~ string }}

Solution 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 ~ ', '%}

Solution 3:

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.