1def type_check(check_type):
 2    def decorator(*valid_argument_types):
 3        def wrapper(func):
 4            def inner(*args):
 5                if check_type == "in":
 6                    if not all(isinstance(arg, valid_argument_types) for arg in args):
 7                        types = ", ".join([str(t) for t in valid_argument_types])
 8                        print(f"Invalid input arguments, expected {types}!")
 9
10                result = func(*args)
11
12                if check_type == "out":
13                    if not isinstance(result, valid_argument_types):
14                        types = ", ".join([str(t) for t in valid_argument_types])
15                        print(f"Invalid output value, expected {types}!")
16
17                return result
18            return inner
19        return wrapper
20    return decorator
21
22@type_check("in")(int, float, complex)
23def power(num, power):
24    return num ** power
25
26@type_check("in")(str)
27@type_check("out")(str)
28def concatenate(*strings, separator=' beep boop '):
29    return separator.join(strings)