def decorator(func):
    def wrapper(butts):
        print("I am a great decorated function that now needs an argument!", butts)
        func()
        print("And this is after the function call.")
    print("Decorating!")
    return wrapper

print("Decorator defined.")

@decorator
def foo():
    print("Bar")

print("Function with decorator defined.")

foo("I am the argument")

print("Function with decorator called.")

def __main__():
    def decorator(func):
        def wrapper(butts):
            print("I am a great decorated function (within a function!) that now needs an argument!", butts)
            func()
            print("And this is after the function call (in a function call!)")
        print("Decorating!")
        return wrapper

    print("Decorator defined.")

    let i = 42
    let l = [1,2,3]

    @decorator
    def foo():
        print("Bar (the inner one)")

    print("Function with decorator defined.")

    foo("I am in the inner wrapper.")

    print("Function with decorator called.")

    print("I like the numbers", l)

print("Calling main.")
__main__()

def methodDecorator(func):
    def wrappedMethod(instance, butts):
        print("I need an extra arg:", butts)
        func(instance)
        print("Done.")
    return wrappedMethod

class Foo():
    def __init__(self):
        self.foo = "bar"
        print("I am an initializer.")
    def undecorated(self):
        print("I am here.")
        print("self.foo =", self.foo)
    @methodDecorator
    def decorated(self):
        print("(decorated) self.foo = ", self.foo)

let f = Foo()
f.undecorated()
print("Returned from f.undecorated()")
f.decorated("butts")
print("Returned from f.decorated()")

def decoratorWithArgument(decoratorArg):
    def theActualDecorator(func):
        print("I am decorating",func.__qualname__,"with this argument:",decoratorArg)
        def wrapped():
            print("This wrapper captured this decorator arg:", decoratorArg)
            func()
        return wrapped
    return theActualDecorator

@decoratorWithArgument("foo")
def decoratedWithArgument():
    print("I don't take any args of mine own, and nor does my wrapper.")

decoratedWithArgument()

def methodDecoratorWithArguments(decoratorArgA, decoratorArgB):
    def theActualDecorator(method):
        print("I am decorating", method.__qualname__, "with these args:", decoratorArgA, decoratorArgB)
        def wrapped(instance, wrapperArg):
            print("I captured these from the decorator:", decoratorArgA, decoratorArgB)
            print("I also take my own argument:", wrapperArg)
            method(instance,"and modify this one")
        return wrapped
    return theActualDecorator

class Bar():
    def __init__(self):
        self.foo = "weee"

    @methodDecoratorWithArguments("foo","bar")
    def superDecoratedMethod(self, arg):
        print("I am method, so I can access myself", self.foo, "and also my own argument which is now", arg)

let b = Bar()
b.superDecoratedMethod("this arg goes to the wrapper")

def genericDecorator(func):
    def wrapper(*args,**kwargs):
        print("I am a generic wrapper, I will pass all of my args along.")
        func(*args,**kwargs)
        print("And I am done.")
    return wrapper

@genericDecorator
def aMethod(with_,args=None):
    print("I got",with_,"and",args)

try:
    aMethod()
except as exception:
    print(exception.arg)

aMethod("just the first")
aMethod("the first","and the second")
aMethod(args="hello",with_="world")
try:
    aMethod(foo="hello",with_="bar")
except as exception:
    print(exception.arg) # unrecognized keyword arg, from inner method

aMethod(*[1,2])
try:
    aMethod(*[1,2,3])
except as exception:
    print(exception.arg) # too many arguments