def is_valid_seq(self, seq):
        return (len(seq) == self.seq_length and
                all(char in self.charset for char in seq))


# BilibiliCaptchaProvider provides captcha from www.bilibili.com
dataset/ETHPy150Open GCC15/bilibili-captcha/captcha_provider.py/NormalSeqSet.is_valid_seq/original