Detecting referenced unset variables. based on https://excess.org/article/2012/04/paranoid-django-templates/

gistfile1.py

class ParanoidContextProxy(object):
    """
    This is a poor-man's proxy for a context instance.

    Make sure template rendering stops immediately on a KeyError.
    """
    def __init__(self, context):
        self.context = context
 
    def __getitem__(self, key):
        try:
            return self.context[key]
        except KeyError:
            raise Exception('ParanoidKeyError: %r' % (key,))

    def __getattr__(self, name):
        return getattr(self.context, name)
    def __setitem__(self, key, value):
        self.context[key] = value
    def __delitem__(self, key):
        del self.context[key]

@contextlib.contextmanager
def paranoid_context_manager(context):
    """
    use ParanoidContextProxy 
    """
    yield ParanoidContextProxy(context)

def paranoid_render_to_response(template_name, dictionary=None,
        context_instance=None, *args, **kwargs):
    """
    use ParanoidContextProxy
    """
    with paranoid_context_manager(context_instance) as c:
        return render_to_response(template_name, dictionary or {}, c, *args, **kwargs)