State saver on Python

withClass.py

class saver:
    state = 0
    def __init__(self, start):
        self.state = start

    def __call__(self, additional):
        self.state += additional
        return self.state

acc = saver(10)
print acc(2)
print acc(3)
print acc(100)

withFunction.py

def saver(start):
    global state
    state = start
    def add(additional):
        global state
        state += additional
        return state
    return add

acc = saver(10)
print acc(2)
print acc(3)
print acc(100)