tarfile.py 文件源码

def seek(self, pos, whence=os.SEEK_SET):
        """Seek to a position in the file.
        """
        if self.closed:
            raise ValueError("I/O operation on closed file")

        if whence == os.SEEK_SET:
            self.position = min(max(pos, 0), self.size)
        elif whence == os.SEEK_CUR:
            if pos < 0:
                self.position = max(self.position + pos, 0)
            else:
                self.position = min(self.position + pos, self.size)
        elif whence == os.SEEK_END:
            self.position = max(min(self.size + pos, self.size), 0)
        else:
            raise ValueError("Invalid argument")

        self.buffer = b""
        self.fileobj.seek(self.position)