python bottle框架 解决跨域问题的正确方式

@hook('before_request')
def validate():
    REQUEST_METHOD = request.environ.get('REQUEST_METHOD')

    HTTP_ACCESS_CONTROL_REQUEST_METHOD = request.environ.get('HTTP_ACCESS_CONTROL_REQUEST_METHOD')
    if REQUEST_METHOD == 'OPTIONS' and HTTP_ACCESS_CONTROL_REQUEST_METHOD:
        request.environ['REQUEST_METHOD'] = HTTP_ACCESS_CONTROL_REQUEST_METHOD


@hook('after_request')
def enable_cors():
    response.headers['Access-Control-Allow-Origin'] = '*'
    # response.headers['Access-Control-Allow-Methods'] = 'GET,POST,PUT,DELETE,OPTIONS'
    response.headers['Access-Control-Allow-Headers'] = '*'