def main(request, response): headers = [(b"Content-Type", b"text/html"), (b"X-Frame-Options", request.GET.first(b"value"))] if b"value2" in request.GET: headers.append((b"X-Frame-Options", request.GET.first(b"value2"))) if b"csp_value" in request.GET: headers.append((b"Content-Security-Policy", request.GET.first(b"csp_value"))) body = u"""