Metaclass for creating classes that allow only a single instance to be created.

redis_cli.py

class MetaSingleton(type):
    """Metaclass for creating classes that allow only a single instance to be created."""

    _instances = {}

    def __call__(cls, *args, **kwargs):
        if cls not in cls._instances:
            cls._instances[cls] = super().__call__(*args, **kwargs)
        return cls._instances[cls]

      

class FastApiRedisCache(metaclass=MetaSingleton):
    """Communicates with Redis server to cache API response data."""

    redis: client.Redis = None

    def init(self) -> None:
        self.redis = redis.from_url(host_url)
        if redis_client.ping():
            return (RedisStatus.CONNECTED, redis_client)