tarfile.py 文件源码

def readsparsesection(self, size):
        """Read a single section of a sparse file.
        """
        section = self.sparse.find(self.position)

        if section is None:
            return ""

        size = min(size, section.offset + section.size - self.position)

        if isinstance(section, _data):
            realpos = section.realpos + self.position - section.offset
            self.fileobj.seek(self.offset + realpos)
            self.position += size
            return self.fileobj.read(size)
        else:
            self.position += size
            return NUL * size
#class _FileInFile