tarfile.py 文件源码

def seek(self, position, whence=io.SEEK_SET):
        """Seek to a position in the file.
        """
        if whence == io.SEEK_SET:
            self.position = min(max(position, 0), self.size)
        elif whence == io.SEEK_CUR:
            if position < 0:
                self.position = max(self.position + position, 0)
            else:
                self.position = min(self.position + position, self.size)
        elif whence == io.SEEK_END:
            self.position = max(min(self.size + position, self.size), 0)
        else:
            raise ValueError("Invalid argument")
        return self.position