inclusion_tag_maybe.py

from django import template
from django.template.loader import get_template

register = template.Library()

@register.inclusion_tag('my_template_for_this_tag.html')
def show_template(template_name):
  """
  Shows the output of a given template.
  Usage:
      {% show_template 'my.html' %}
      
  """
  html = get_template(template_name)
  return {'html': html}

====================================================================

my_template_for_this_tag.html:

<h4>Here is the template source</h4>
<pre>
   {% autoescape off %}
    {{ html }}
   {% autoescape on %} 
</pre>
<h4>And it renders as...</h4>
  {{ html }}