python迭代器斐波那契

以下是两种Python迭代器实现斐波那契数列的例子：

1. 使用itertools模块的islice函数实现斐波那契数列迭代器：

from itertools import islice

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

if __name__ == '__main__':
    fib = Fib()
    print(list(islice(fib, 0, 10)))  # 输出：[1, 1, 2, 3, 5, 8, 13, 21, 34, 55]

2. 使用迭代器方法实现斐波那契数列迭代器：

class Fibonacci:
    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:
            result = self.a
            self.a, self.b = self.b, self.a + self.b
            self.current_num += 1
            return result
        else:
            raise StopIteration

fibo = Fibonacci(10)
for num in fibo:
    print(num)  # 输出：0, 1, 1, 2, 3, 5, 8, 13, 21, 34