Python decorating class

Question

I'm trying to decorate a class with arguments but cannot get it to work:

This is the decorator:

 def message(param1, param2):
   def get_message(func):
        func.__init__(param1,param2)

   return get_message

class where I want to put the decorator

@message(param1="testing1", param2="testing2")
class SampleClass(object):
   def __init__(self):
     pass

But this is not working , I am getting an error when running this. Does anyone know what the problem ?, I am trying to create a decorator to initialise classes with some values.

Answer 1

I'm having trouble figuring out what you're trying to do. If you want to decorate a class with a decorator that takes arguments, one way to do it is like this.

2020-09-03:

Thank you Maria-Ines Carrera for pointing out that the original code doesn't actually handle classes inheriting from other classes correctly and user2357112 supports Monica for proposing a solution that does work.

# function returning a decorator, takes arguments
def message(param1, param2):
    # this does the actual heavy lifting of decorating the class
    # it takes the original class, modifies it in place, and returns
    # the same class
    def wrapper(wrapped):
        the_init = wrapped.__init__

        def new_init(self):
            self.param1 = param1
            self.param2 = param2
            the_init(self)

        def get_message(self):
            return "message %s %s" % (self.param1, self.param2)

        wrapped.__init__ = new_init
        wrapped.get_message = get_message

        return wrapped
    return wrapper


class Pizza(object):
    def __init__(self):
        print "Pizza initialization"


@message("param1", "param2")
class Pizza2(Pizza):
    def __init__(self):
        print "Pizza2 initialization"
        super(Pizza2, self).__init__()

pizza_with_message = Pizza2()

# prints "message param1 param2"
print pizza_with_message.get_message()

This prints the following:

Pizza2 initialization
Pizza initialization
message param1 param2