修改迭代器方法計算斐波那契數列

class Fibs:
    def __init__(self,n=20):
        self.a = 0
        self.b = 1
        self.n = n
    def __iter__(self):
        return self
    def __next__(self):
        self.a,self.b = self.b,self.a + self.b
        if self.a > self.n:    #限制最大值，不然會死循環
            raise StopIteration   
        return self.a

fibs = Fibs(120)

for each in fibs:
    print(each)