方法1:使用list在函数内部引用其地址，并改变其值

def createCounter():
    a = [0]
    def counter():
        a[0] += 1
        return a[0]
    return counter

*方法2：利用迭代器，完成数值增1

def createCounter():
    def counter():
        n = 1
        while True:
            yield n
            n += 1
    c = counter()  
    def g():
        return next(c)
    return g