Could not parse the remainder in Django If/else statements in templates

Question

I have a couple if/else statements that all seem to return this same parse error regardless of what page or other content exists on the page.

For all intents and purposes have dumbed it down. My actual logic makes sense, don't worry, I just want to know what of my syntax is causing this problem:

<div>
    {% if True and 10 - 1 > 5 %}
        <p>1</p>
    {% else %}
        <p>2</p>
    {% endif %}
</div>

When I do the above, I expect it to show the <p>1</p> tag but instead returns a "TemplateSyntaxError at " URL, Could not parse remainder: '-' from '-'.

Answer 1

By default, django templates does not allow math operations such as addition, subtraction, etc..

I would suggest to make the mathematical operation in your view function and render it to the template, and then use it directly Example:

def my_view(request):
    result = 10 - 1
    render(request, template, context={'my_result': result})

and then in the template you would do something like

{% if True and my_result > 5 %}

Answer 2

<div>
    {% if True and 10|add:'-1' > 5 %}
        <p>1</p>
    {% else %}
        <p>2</p>
    {% endif %}
</div>

The code 10|add:'-1' means 10 + (-1)