Get list item dynamically in django templates

I notice that @e-satis mentioned it, but I think the built-in slice template tag deserves some love.

{{ item | slice:"2" }} #gets the third element of the list

The slice tag in Django templates may use python's slicing code, but the syntax is unmistakably different. For instance, if you wanted to get an element of a sequence with a variable, in python you'd write something similar to the following:

>>>mylist = ["0th Element", "1th Element"]
>>>zero, one = 0, 1
>>>mylist[zero]
"0th Element"
>>>mylist[one]
"1th Element"

Using this syntax with the Django slice template tag will return a sliced list in every case, of dubious utility for getting an item of known index:

{% with "0" as zero %}
{% with "1" as one %}
{% with "2" as two %}

{{mylist|slice:zero}} {{mylist|slice:one}} {{mylist|slice:two}}

{% endwith %}
{% endwith %}
{% endwith %}

Renders to the html:

[] ["0th Element"] ["0th Element", "1th Element"]

Note the differences: you are getting the result of mylist[:x] instead of mylist[x].

Django provides enough tools to work around this. The first trick is to use explicit slices like 0:1 for your indices, and then |join:"" the resultant list into a single element. Like so:

{% with "0:1" as zero %}
{{mylist|slice:zero|join:""}}
{% endwith %}

Yields:

0th Element

This comes in particularly handy if you need to access a parent loop's index when dealing with an iterable inside a child loop:

{% for parent in parent_loop %}
    {% cycle "0:1" "1:2" "2:3" as parent_loop_index silent %}
    {% for child in child_loop %}
        {{child|slice:parent_loop_index|join:""}}
    {% endfor %}
{% endfor %}

Completed with nothing but stock parts, although I don't think Django has implemented achievements yet.

Are you sure you can't just do:

{% for item in mylist %}
    {{ item }}
{% endfor %}

With the slice filter, you can even do some customisation.

This is not possible directly because Django thinks that "x" is the key to lookup in mylist - instead of the value of x. So, when x = 5, Django tries to look up mylist["x"] instead of mylist[5].

Use the following filter as workaround:

@register.filter
def lookup(d, key):
    return d[key]

and use it like

{{ mylist|lookup:x }}