import http.server, socketserver

class H(http.server.SimpleHTTPRequestHandler):
    def end_headers(self):
        self.send_header('Content-Disposition', 'attachment; filename="docx_template.docx"')
        super().end_headers()

socketserver.TCPServer.allow_reuse_address = True
with socketserver.TCPServer(('', 8000), H) as httpd:
    httpd.serve_forever()