config.py 文件源码

def __init__(self, mapping: Mapping, *fallback_configs: Configuration) -> None:
        super().__init__(mapping)
        # for fb_c in fallback_configs:
        #     if not isinstance(fb_c, Configuration):
        #         raise ValueError(f"{fb_c!r} is not an instance of {Configuration}")
        self.fallback_configs = fallback_configs