apply_pattern

def apply_pattern(pattern: str, current: str) -> bool:
    """Apply a pattern to a routing key."""
    pattern_queue = iter(pattern.split("."))
    current_queue = iter(current.split("."))

    pattern_symb = next(pattern_queue, None)
    while pattern_symb:
        if (next_symb := next(current_queue, None)) is None:
            return False

        elif pattern_symb == "#":
            next_pattern = next(pattern_queue, None)

            if next_pattern is None:
                return True

            if (next_symb := next(current_queue, None)) is None:
                return False

            while next_pattern == "*":
                next_pattern = next(pattern_queue, None)
                if (next_symb := next(current_queue, None)) is None:
                    return False

            while next_symb != next_pattern:
                if (next_symb := next(current_queue, None)) is None:
                    return False

            pattern_symb = next(pattern_queue, None)

        elif pattern_symb == "*" or pattern_symb == next_symb:
            pattern_symb = next(pattern_queue, None)

        else:
            return False

    return next(current_queue, None) is None