How can I use the same parameters in a decorator with that in the functions in Python?

Question

I want use a same param in decorater and function like:

def outer(deco_param):
    def decorator(func):
        print("param:%s" % deco_param)
        return func
    return decorator


@outer(deco_param=s)    # problems here: 's' is unreferenced
def test(s):
    print("test:%s" % s)

I got this idea when using Flask but I didn't know how did they make it, which supports using a param of view function in its decorater like:

app.route(rule="/user/<int:uid>")
def access_user(uid):  # if I use any other name except from 'uid', IDE would raise a tip
    ...

What's more, Flask seems to make a static check . If I miss uid argument or use any other name, IDE(pycharm) would raise a tip of "Function 'access_user` doesn't have a parameter 'int:uid'". That's the effect I want.

Can anyone please give me some advice? Thanks

Answer 1

You don't need to pass the same parameter to both the outer function and the inner function. To call the parameters via decorator, you should add a wrapper function to pass the parameters (*args) from inner one to outer one.

You can write like this:

def outer():
    def decorator(func):
        def wrapper(*args):
            print("param:%s" % func.__param__)
            return func(*args)
        return wrapper
    return decorator


@outer
def test(s):
    print("test:%s" % s)