自封装函数参数检索

import inspect


class CheckParams:

    def __init__(self, fn):
        self.fn_params = inspect.signature(fn).parameters

    @property
    def get_required_kw_args(self):                 # 必须存在的关键字参数
        args = []
        for name, param in self.fn_params.items():
            if param.kind == inspect.Parameter.KEYWORD_ONLY and param.default == inspect.Parameter.empty:
                args.append(name)
        return tuple(args)

    @property
    def get_named_kw_args(self):                    # 有名字的关键字参数
        args = []
        for name, param in self.fn_params.items():
            if param.kind == inspect.Parameter.KEYWORD_ONLY:
                args.append(name)
        return tuple(args)

    @property
    def get_required_args(self):                    # 位置参数(必须存在的)
        args = []
        for name, params in self.fn_params.items():
            if params.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD:
                args.append(name)
        return tuple(args)


def foo(a, b, *args, c, request, d=None, e, **kwargs):
    pass


checker = CheckParams(foo)

print(checker.get_named_kw_args)        # ('c', 'request', 'd', 'e')
print(checker.get_required_args)        # ('a', 'b')
print(checker.get_required_kw_args)     # ('a', 'b')