import redis

class DataBase:

    def __init__(self, host, port):

        self.host = host

        self.port = port

    def read_string(self, key):

        try:

            r = redis.StrictRedis(host=self.host, port=self.port)

            result = r.get(key)

            return result

        except Exception as exception:

            print(exception)     

    def read_list(self, key, n):

        try:

            r = redis.StrictRedis(host=self.host, port=self.port)

            if n > r.llen(key):

                result = r.lrange(0, -1)

            else:

                result = r.lrange(key, 0, n)

            return result

        except Exception as exception:

            print(exception) 

    def read_set(self, key):

        try:

            r = redis.StrictRedis(host=self.host, port=self.port)

            result = r.smembers(key)

            return result

        except Exception as exception:

            print(exception)

    def read_hash(self, key):

        try:

            r = redis.StrictRedis(host=self.host, port=self.port)

            result = r.hgetall(key)

            return result

        except Exception as exception:

            print(exception)

    def read_sort_set(self, key, n):

        try:

            r = redis.StrictRedis(host=self.host, port=self.port)

            if n > r.zcard(key):

                result = r.zrange(0, -1)

            else:

                result = r.zrange(0, n)

            return result

        except Exception as exception:

            print(exception)