def get_ab_template(request, default=None):
    template_name = request.GET.get(SIMPLE_TEMPLATES_AB_PARAM)
    if template_name:
        if default:
            (filepath, extension) = os.path.splitext(default)
            template_name = os.path.join(SIMPLE_TEMPLATES_AB_DIR, filepath, template_name + extension or '')
        return find_template(template_name) or default
    return default
This function simply returns the a/b template path if the ab GET parameter exists, otherwise the contents of `default`.
dataset/ETHPy150Open jaddison/django-simple-templates/simple_templates/utils.py/get_ab_template