Use a different template filter

I don’t think that the getattr template filter is very suitable for your purposes. I don’t like the has_key check, because it will return False, even though 'field_name' in Form is True.

You might be able to get the template tag to work by setting attributes on the form, but it seems hacky to me. A better approach would be to use a different template filter.

If you have a form, then you can access the field answer_1 with form['answer_1']. Using this knowledge, it’s easy to create a more suitable template filter.

@register.filter(name='get_form_field')
def get_form_field(form, field_name):
    try:
        return form[field_name]
    except KeyError:
        return settings.TEMPLATE_STRING_IF_INVALID

Then, in your template, you can do

{{ form|get_form_field:"answer_1" }}

Or, if you are using the with template tag:

{% with "answer_1" as ans %}
    {{ form|get_form_field:ans }}
{% endwith %}

Or try a different approach

Actually, I’m not sure that you need a special template filter at all. You could add a method to your form, that returns a list of the fields you want to display.

class MyForm(forms.Form):
    def answer_fields(self):
        return [self['answer_%d' % x] for range(1, 5)] 

Then in your template, loop through the list and render them.

{% for field in form.answer_fields %}
    {{ form.answer_fields }}
{% endfor %}