Django - How to do tuple unpacking in a template 'for' loop

Question

In my views.py, I'm building a list of two-tuples, where the second item in the tuple is another list, like this: ``` [ Product_Type_1, [ product_1, product_2 ], Product_Type_2, [ product_3, product_4 ]] ``` In plain old Python, I could iteration the list like this: ``` for product_type, products in list: print product_type for product in products: print product ``` I can't seem to do the same thing in my Django template: ``` {% for product_type, products in product_list %} print product_type {% for product in products %} print product {% endfor %} {% endfor %} ``` I get this error from Django: Caught an exception while rendering: zip argument #2 must support iteration Of course, there is some HTML markup in the template, not print statements. Is tuple unpacking not supported in the Django template language? Or am I going about this the wrong way? All I am trying to do is display a simple hierarchy of objects - there are several product types, each with several products (in models.py,…

Accepted Answer

it would be best if you construct your data like {note the '(' and ')' can be exchanged for '[' and ']' repectively, one being for tuples, one for lists}

```
[ (Product_Type_1, ( product_1, product_2 )),
   (Product_Type_2, ( product_3, product_4 )) ]
```

and have the template do this:

```
{% for product_type, products in product_type_list %}
    {{ product_type }}
    {% for product in products %}
        {{ product }}
    {% endfor %}
{% endfor %}
```

the way tuples/lists are unpacked in for loops is based on the item returned by the list iterator. each iteration only one item was returned. the first time around the loop, Product_Type_1, the second your list of products...

Django - How to do tuple unpacking in a template 'for' loop

Solution

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