Assign the inner loop result into a variable - django-templates

Question

I have a loop like this in my django template and this having an inner loop
{% for productinfo in product_list %}
<tr>
<td>{{productinfo.attr}}</td>
<td>
<select class="form-control seller-combo" name="category">
<option value="">Select Attributes</option>
{% for attr in product_list %}
<option value="{{attr|mongo_id}}">{{ attr.attr }}</option>
{% endfor %}
</select>
</td>
</tr>
{% endfor %}
My problem is that each time when the outer loop is running the inner loop also run many times. I want to remove the inner loop from this and want to call this inner loop before the outer loop is running.
Like example the code should be like this,
{% for attr in product_list %}
<option value="{{attr|mongo_id}}">{{ attr.attr }}</option>
{% endfor %}
And assign the result of this code into a variable say it as result
Then attach this result like this,
{% for productinfo in product_list %}
<tr>
<td>{{productinfo.attr}}</td>
<td>
<select class="form-control seller-combo" name="category">
<option value="">Select Attributes</option>
{{result}}
</select>
</td>
</tr>
{% endfor %}
Doing like this i can increase my code performance

Answer 1

{% for attr in product_list %}
<option value="{{attr|mongo_id}}">{{ attr.attr }}</option>
{% endfor %}
make this as a seperate template this.html and {% include 'this.html' %}
OR
to increase the performance use with tag
{% with product_list as p_list %}
"write your for loop"
{% endwith %}