view.py 文件源码

def get_request_param(request: web.Request, name: str, error_if_missing: bool = True) -> Optional[str]:
    """Get a single value from a request GET parameter.

    Optionally error if it is missing.
    """
    if name not in request.rel_url.query:
        if error_if_missing:
            raise errors.NotFound()
        else:
            return None
    ret = request.rel_url.query[name]
    return ret