fib_iter

class FibonacciIterator:
    def __init__(self, max):
        self.max = max
    def __iter__(self):
        return self

    def __next__(self):
        fib = self.x
        if fib > self.max:
            raise StopIteration
        self.x, self.y = self.y, self.x + self.y
        return fib