loader.py 文件源码

def load_config_file(self, config_paths):
        """Load a yaml config file from path."""
        config_path = ""
        for possible_path in config_paths:
            if not os.path.isfile(possible_path):
                _LOGGER.debug("Config file %s not found.", possible_path)
            else:
                config_path = possible_path
                break

        if not config_path:
            _LOGGER.info("No configuration files found.")
            config_path = self.create_default_config(DEFAULT_CONFIG_PATH)

        env_var_pattern = re.compile(r'^\$([A-Z_]*)$')
        yaml.add_implicit_resolver("!envvar", env_var_pattern)

        def envvar_constructor(loader, node):
            """Yaml parser for env vars."""
            value = loader.construct_scalar(node)
            [env_var] = env_var_pattern.match(value).groups()
            return os.environ[env_var]

        def include_constructor(loader, node):
            """Add a yaml file to be loaded inside another."""
            main_yaml_path = os.path.split(stream.name)[0]
            included_yaml = os.path.join(main_yaml_path,
                                         loader.construct_scalar(node))

            with open(included_yaml, 'r') as included:
                return yaml.load(included)

        yaml.add_constructor('!envvar', envvar_constructor)
        yaml.add_constructor('!include', include_constructor)

        try:
            with open(config_path, 'r') as stream:
                _LOGGER.info("Loaded config from %s.", config_path)
                return yaml.load(stream)
        except yaml.YAMLError as error:
            self.opsdroid.critical(error, 1)
        except FileNotFoundError as error:
            self.opsdroid.critical(str(error), 1)