4.如果U盘处于挂载状态，弹出U盘后重启系统；如果U盘未处于挂载状态直接重启系统，重启后拷贝文件至U盘恢复正常。/dev/sdc1 是U盘标识，根据第一步实际输出结果输入，注意卸载后不要拔出U盘。dosfsck 只针对FAT32文件系统。

生成26个大小写字母和0-9的六位随机验证码```pythonimport randomimport string‘’’s = [‘A’, ‘B’, ‘C’, ‘D’, ‘E’, ‘F’, ‘G’, ‘H’, ‘I’, ‘J’, ‘K’, ‘L’, ‘M’, ‘N’, ‘O’, ‘P’, ‘Q’, ‘R’, ‘S’, ‘T’, ‘U’,‘V’, ‘W’, ‘X’, ‘Y’, ‘Z’, ‘0’, ‘

匹配单字符-数字\d表示0-9的数字,只匹配一个import reresult = re.match(r"\d","3python")print(result)result = re.match(r"\d","python3")print(result)运行结果<re.Match object; span=(0, 1), match=‘3’>Nonematch是从前往后进行匹配，如果刚