def fib_generator():
    a, b = 0, 1
    yield 0
    while True:
        a, b = b, a + b
        yield a

def nums_lt(nums):
    user_number = int(input('Enter a threshold: '))
    new_nums = [n for n in nums if n < user_number]
    return  new_nums

if __name__ == '__main__':

    fibonacci_numbers = []
    fib = fib_generator()
    for n in range(12):
        fibonacci_numbers.append(next(fib))

    print(fibonacci_numbers)
    print(nums_lt(fibonacci_numbers))