1 class Fib(object):
 2 
 3     def __init__(self):
 4         self.a,self.b=0,1
 5 
 6     def __iter__(self):
 7         return self
 8 
 9     def __next__(self):
10         self.a,self.b=self.b,self.a+self.b
11         if self.a > 100:
12             raise StopIteration()
13         return self.a

运行

for n in Fib():
    print(n)

结果

1
1
2
3
5
8
13
21
34
55
89