How to test for a List in Jinja2?

Question

As far as I can see, there is no way to test if an object is a List instance in Jinja2.

Is that correct and has anyone implemented a custom test/extension in Jinja2?

Answer 1

I did it like this:

{% if var is iterable and (var is not string and var is not mapping) %} 

You can find a list of all jinja tests here.

Answer 2

You can easily do this whit a custom filter in jinja2.

First create you test method:

def is_list(value):     return isinstance(value, list) 

And add it as an custom filter:

j = jinja2.Jinja2(app) j.environment.filters.update({         'is_list': is_list, })