I think it's appropriate to add the generator fib() to the math module. With fib(), some operations will be easier.

The generator is like this:

def fib(count=None):
    if count is not None and not isinstance(count, int):
        raise ValueError(f"Parameter count has an unexpected type: {count.__class__.__name__}.")
    a, b = 0, 1
    while True:
        a, b = b, a + b
        if count is not None:
            if not count:
                return
            count -= 1
        yield a