client.py 文件源码

def get_class(api_name, version, version_map):
        """Returns the client class for the requested API version

        :param api_name: the name of the API, e.g. 'compute', 'image', etc
        :param version: the requested API version
        :param version_map: a dict of client classes keyed by version
        :rtype: a client class for the requested API version
        """
        try:
            client_path = version_map[str(version)]
        except (KeyError, ValueError):
            msg = _("Invalid %(api_name)s client version '%(version)s'. "
                    "Must be one of: %(version_map)s") % {
                        'api_name': api_name,
                        'version': version,
                        'version_map': ', '.join(version_map.keys())}
            raise exceptions.UnsupportedVersion(msg)

        return importutils.import_class(client_path)