[Fixed]-Change List in Embedded For Loop in Django Template

Why don’t you do the work in the view instead of trying to come up with something complicated in the template?

For example, in your Python:

names = ['apple', 'orange', 'carrot']
colors = [ ['red', 'green'], ['orange', 'red'], ['orange', 'yellow'] ]
fruits = zip(names, colors)

And then in your template:

{% for name, colors in fruits %}
  <div>
  {{ name }} -
  {% for color in colors %}
    {{ color }}
  {% endfor %}
  </div> 
{% endfor %}

If I understand you correctly, what you want to do is something like form[matrix_row]

{% for matrix_row in request.session.matrix_rows %}
    {% for radio in form[matrix_row] %}
       <li>{{ radio }}</li>
    ...

That isn’t possible in Django templates, so you would need to add your own simple templatetag for that. Something like this

@register.filter
def keyvalue(dic, key):
    """Use a variable as a dictionary key"""
    return dic[key]

And now you can do

{% for matrix_row in request.session.matrix_rows %}
    {% for radio in form|keyvalue:matrix_row %}
       <li>{{ radio }}</li>
    ...