两种方法递归斐波那契数列

__author__ = 'hechangting'
#ecoding=utf-8
import itertools
#迭代器
class Fib:
    def __init__(self):
        self.prev = 0
        self.curr = 1

    def __iter__(self):
        return self

    def __next__(self):
        value = self.curr
        self.curr += self.prev
        self.prev = value
        return value

#生成器
class fib1:
    def fib(self,times):
        n=0
        a,b=0,1
        while n<times:
            yield b
            a,b=b,a+b
            n+=1
        return 'done'

for n in fib1().fib(5):
    print(n)
print("="*50)

f=Fib()
print(list(itertools.islice(f,0,2)))