[b'/dev/nvme0n1\n/dev/nvme1n1\n/dev/nvme2n1\n/dev/nvme3n1\n']，python3如何切片得到['/dev/nvme0','/dev/nvme1','/dev/nvme2','/dev/nvme3']

可以使用列表推导式和字符串切片来实现：

lst = [s[:9] for s in b'/dev/nvme0n1\n/dev/nvme1n1\n/dev/nvme2n1\n/dev/nvme3n1\n'.decode('utf-8').split()]

首先将字节串 b'/dev/nvme0n1\n/dev/nvme1n1\n/dev/nvme2n1\n/dev/nvme3n1\n' 转换为字符串，然后再用字符串的 split 方法将其按照换行符分隔成一个列表。接着使用列表推导式和字符串切片将每个字符串切片并取出前 9 个字符，最终得到 ['/dev/nvme0','/dev/nvme1','/dev/nvme2','/dev/nvme3']。