backends.py 文件源码

def _normalize_name(self, name):
        """
        Normalizes the name so that paths like /path/to/ignored/../foo.txt
        work. We check to make sure that the path pointed to is not outside
        the directory specified by the LOCATION setting.
        """

        base_path = force_text(self.location)
        base_path = base_path.rstrip('/')

        final_path = urljoin(base_path.rstrip('/') + "/", name)

        base_path_len = len(base_path)
        if (not final_path.startswith(base_path) or
                final_path[base_path_len:base_path_len + 1] not in ('', '/')):
            raise SuspiciousOperation("Attempted access to '%s' denied." %
                                      name)
        return final_path.lstrip('/')