def fib(stop):
    """
    A generator function for fibonnaci
    :return:
    """
    times = 0
    prev_prev = 1
    prev = 0
    fib_num = 0
    while times < stop:
        yield fib_num
        fib_num = prev + prev_prev
        prev_prev = prev
        prev = fib_num
        times += 1


for num in fib(10):
    print(num)