It seems to me that POSITIONAL_OR_KEYWORD is the most often used kind of Parameter (after all, this is the "default" kind of Parameter), so perhaps the constructor for Parameter could be changed from def __init__(self, name, kind, *, default=_empty, annotation=_empty, _partial_kwarg=False): to def __init__(self, name, kind=Parameter.POSITIONAL_OR_KEYWORD, *, default=_empty, annotation=_empty, _partial_kwarg=False): Any thoughts on that? Best, Antony