def get_items_from_user() -> list:
    items = []
    while True:
        item = input("Что добавить? ")
        items.append(item)
        if input("Остановить? (y/n): ").lower() == 'y':
            break
    return items

def show_items(items: list):
    for item in items:
        print(item)

user_items = get_items_from_user()
show_items(user_items)