loaders.py 文件源码

def list_api_versions(self, service_name, type_name):
        """List all API versions available for a particular service type

        :type service_name: str
        :param service_name: The name of the service

        :type type_name: str
        :param type_name: The type name for the service (i.e service-2,
            paginators-1, etc.)

        :rtype: list
        :return: A list of API version strings in sorted order.

        """
        known_api_versions = set()
        for possible_path in self._potential_locations(service_name,
                                                       must_exist=True,
                                                       is_dir=True):
            for dirname in os.listdir(possible_path):
                full_path = os.path.join(possible_path, dirname, type_name)
                # Only add to the known_api_versions if the directory
                # contains a service-2, paginators-1, etc. file corresponding
                # to the type_name passed in.
                if self.file_loader.exists(full_path):
                    known_api_versions.add(dirname)
        if not known_api_versions:
            raise DataNotFoundError(data_path=service_name)
        return sorted(known_api_versions)