template of a parametric decorator

decorator_example.py

from functools import wraps

class print_in_out:
    def __init__(self, in_str, out_str):
        self.in_str = in_str
        self.out_str = out_str

    def __call__(self, f):
        @wraps(f)
        def wrapped(*args, **kargs):
            print('inn: {}'.format(self.in_str))
            ris = f(*args, **kargs)
            print('out: {}'.format(self.out_str))
            return ris
        return wrapped

@print_in_out("hello", "world")
def sayHello(a1, a2, a3, a4):
    print('sayHello arguments:', a1, a2, a3, a4)
    return 'lol'

ris = sayHello("say", "hello", "argument", "list")
print(ris)