斐波拉契数列

斐波拉契数列，数列第一个数为0，第二个数为1，其后的每一个数可由前两个数相加得到：0、1、1、2、3、5、8、13、21......

# nums = list()
#
# a = 0
# b = 1
#
# i = 0
# while i < 10:
#     nums.append(a)
#     a,b=b,a+b
#     i+=1
# for num in nums:
#     print(num)

class Fibonacci(object):
    def __init__(self,all_num):
        self.all_num = all_num
        self.current_num = 0
        self.a = 0
        self.b = 1

    def __iter__(self):
        return self
    def __next__(self):
       if self.current_num < self.all_num:
           ret = self.a
           self.a,self.b = self.b,self.a+self.b
           self.current_num += 1
           return ret
       else:
           raise StopIteration

fibo = Fibonacci(10)

for num in fibo:
    print(num)