config.py 文件源码

def upgrade(self, cfg):
        fields = []
        fields_env = {}

        # ENV gets priority: ENV < config.json
        for name, data in self.base_config.items():
            if name not in cfg:
                cfg[name] = data
                fields.append(name)

            if name in os.environ:
                # Use JSON decoder to get same behaviour as config file
                fields_env[name] = json.JSONDecoder().decode(os.environ[name])
                logger.info("Using ENV setting %s=%s", name, fields_env[name])

        # Only rewrite config file if new fields added
        if len(fields):
            logger.warn("Upgraded config, added %d new field(s): %r", len(fields), fields)
            self.save(cfg)

        # Update in-memory config with environment settings
        cfg.update(fields_env)

        return cfg