import unicodedata


def parse_seconds(s: str) -> int | None:
    """解析 '30' 或 '3*60' 形式的时长秒数,非法输入返回 None"""
    s = s.strip()
    if not s or not all(c.isdigit() or c == "*" for c in s):
        return None
    try:
        result = 1
        for part in s.split("*"):
            result *= int(part)
        return result
    except ValueError:
        return None


def strip_prefix(text: str, prefixes) -> str:
    """依次移除前缀后去空白"""
    for p in prefixes:
        text = text.removeprefix(p)
    return text.strip()


def is_number(s) -> bool:
    """判断字符串是否可视为数字"""
    try:
        float(s)
        return True
    except ValueError:
        pass
    try:
        unicodedata.numeric(s)
        return True
    except (TypeError, ValueError):
        pass
    return False