如何使用Python库连接Redis

1、redis-py 库封装一个 Redis 工具类可以帮助我们简化 Redis 的操作并提高代码的复用性和可维护性。

• 安装redis

pip install redis

import redis
import logging

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

class RedisUtils:
    def __init__(self, host='localhost', port=6379, db=0, decode_responses=True,password=None):
        """
        初始化 Redis 连接
        
        :param host: Redis 主机，默认为 localhost
        :param port: Redis 端口，默认为 6379
        :param db: Redis 数据库，默认为 0
        :param decode_responses: 如果为 True，则自动解码 Redis 返回的字节串为字符串
        :param password: Redis密码（如果设置了密码）
        """
        self.host = host
        self.port = port
        self.db = db
        self.decode_responses = decode_responses

        # 创建 Redis 连接实例
        self.redis = redis.StrictRedis(
        	host=self.host,
        	 port=self.port, 
        	 db=self.db, 
        	 decode_responses=self.decode_responses,
        	 password=password
        )

    def set(self, key, value, ex=None, px=None, nx=False, xx=False):
        """
        设置 Redis 键值对
        
        :param key: 键
        :param value: 值
        :param ex: 键值对过期时间（秒）
        :param px: 键值对过期时间（毫秒）
        :param nx: 只在键不存在时设置
        :param xx: 只在键存在时设置
        :return: 执行结果（True 或 False）
        """
        try:
            result = self.redis.set(key, value, ex=ex, px=px, nx=nx, xx=xx)
            logger.info(f"Set key '{key}' with value '{value}'")
            return result
        except Exception as e:
            logger.error(f"Error setting key '{key}': {e}")
            return None

    def get(self, key):
        """
        获取 Redis 键的值
        
        :param key: 键
        :return: 值（如果不存在则返回 None）
        """
        try:
            value = self.redis.get(key)
            logger.info(f"Get key '{key}' with value '{value}'")
            return value
        except Exception as e:
            logger.error(f"Error getting key '{key}': {e}")
            return None

    def delete(self, key):
        """
        删除 Redis 键
        
        :param key: 键
        :return: 删除结果（删除的键的数量）
        """
        try:
            result = self.redis.delete(key)
            logger.info(f"Deleted key '{key}'")
            return result
        except Exception as e:
            logger.error(f"Error deleting key '{key}': {e}")
            return None

    def exists(self, key):
        """
        判断 Redis 键是否存在
        
        :param key: 键
        :return: 是否存在（True 或 False）
        """
        try:
            exists = self.redis.exists(key)
            logger.info(f"Key '{key}' exists: {exists}")
            return exists
        except Exception as e:
            logger.error(f"Error checking existence of key '{key}': {e}")
            return False

    def hset(self, name, key, value):
        """
        设置哈希表中的字段
        
        :param name: 哈希表名
        :param key: 字段名
        :param value: 字段值
        :return: 执行结果
        """
        try:
            result = self.redis.hset(name, key, value)
            logger.info(f"Set hash '{name}' field '{key}' with value '{value}'")
            return result
        except Exception as e:
            logger.error(f"Error setting hash '{name}' field '{key}': {e}")
            return None

    def hget(self, name, key):
        """
        获取哈希表中的字段
        
        :param name: 哈希表名
        :param key: 字段名
        :return: 字段值
        """
        try:
            value = self.redis.hget(name, key)
            logger.info(f"Get hash '{name}' field '{key}' with value '{value}'")
            return value
        except Exception as e:
            logger.error(f"Error getting hash '{name}' field '{key}': {e}")
            return None

    def lpush(self, name, *values):
        """
        向 Redis 列表左侧插入元素
        
        :param name: 列表名
        :param values: 要插入的值
        :return: 执行结果（列表长度）
        """
        try:
            result = self.redis.lpush(name, *values)
            logger.info(f"LPush to list '{name}' values {values}")
            return result
        except Exception as e:
            logger.error(f"Error pushing to list '{name}': {e}")
            return None

    def lrange(self, name, start, end):
        """
        获取 Redis 列表中的元素
        
        :param name: 列表名
        :param start: 起始索引
        :param end: 结束索引
        :return: 列表元素
        """
        try:
            values = self.redis.lrange(name, start, end)
            logger.info(f"LRANGE from list '{name}' from index {start} to {end} with values {values}")
            return values
        except Exception as e:
            logger.error(f"Error getting range from list '{name}': {e}")
            return None

    def sadd(self, name, *values):
        """
        向 Redis 集合添加元素
        
        :param name: 集合名
        :param values: 要添加的值
        :return: 添加的元素数量
        """
        try:
            result = self.redis.sadd(name, *values)
            logger.info(f"SAdd to set '{name}' values {values}")
            return result
        except Exception as e:
            logger.error(f"Error adding to set '{name}': {e}")
            return None

    def smembers(self, name):
        """
        获取 Redis 集合中的所有元素
        
        :param name: 集合名
        :return: 集合中的元素
        """
        try:
            values = self.redis.smembers(name)
            logger.info(f"SMEMBERS from set '{name}' with values {values}")
            return values
        except Exception as e:
            logger.error(f"Error getting members from set '{name}': {e}")
            return None

    def close(self):
        """
        关闭 Redis 连接
        """
        try:
            self.redis.close()
            logger.info("Redis connection closed.")
        except Exception as e:
            logger.error(f"Error closing Redis connection: {e}")

2、redis-py-cluster 是一个 Python 库，它允许你使用 Redis 集群

• 安装redis-py-cluster

pip install redis-py-cluster

from rediscluster import RedisCluster
import logging

# 设置日志记录
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

class RedisClusterUtils:
    def __init__(self, startup_nodes, decode_responses=True,password=None):
        """
        初始化 Redis 集群连接
        
        :param startup_nodes: Redis 集群的初始节点列表
        :param decode_responses: 如果为 True，自动解码 Redis 返回的字节串为字符串
        """
        self.startup_nodes = startup_nodes
        self.decode_responses = decode_responses
        self.password = password
        try:
            # 初始化 Redis 集群客户端
            self.redis = RedisCluster(startup_nodes=startup_nodes, decode_responses=decode_responses,password=password)
            logger.info("Connected to Redis cluster successfully.")
        except Exception as e:
            logger.error(f"Error connecting to Redis cluster: {e}")
            raise

    def set(self, key, value, ex=None, px=None, nx=False, xx=False):
        """
        设置 Redis 键值
        
        :param key: 键
        :param value: 值
        :param ex: 设置过期时间（秒）
        :param px: 设置过期时间（毫秒）
        :param nx: 只在键不存在时设置
        :param xx: 只在键存在时设置
        :return: 执行结果
        """
        try:
            result = self.redis.set(key, value, ex=ex, px=px, nx=nx, xx=xx)
            logger.info(f"Set key '{key}' with value '{value}'")
            return result
        except Exception as e:
            logger.error(f"Error setting key '{key}': {e}")
            return None

    def get(self, key):
        """
        获取 Redis 键的值
        
        :param key: 键
        :return: 值
        """
        try:
            value = self.redis.get(key)
            logger.info(f"Get key '{key}' with value '{value}'")
            return value
        except Exception as e:
            logger.error(f"Error getting key '{key}': {e}")
            return None

    def delete(self, key):
        """
        删除 Redis 键
        
        :param key: 键
        :return: 删除操作的结果
        """
        try:
            result = self.redis.delete(key)
            logger.info(f"Deleted key '{key}'")
            return result
        except Exception as e:
            logger.error(f"Error deleting key '{key}': {e}")
            return None

    def hset(self, name, key, value):
        """
        设置哈希表字段
        
        :param name: 哈希表名
        :param key: 字段
        :param value: 值
        :return: 执行结果
        """
        try:
            result = self.redis.hset(name, key, value)
            logger.info(f"Set hash '{name}' field '{key}' with value '{value}'")
            return result
        except Exception as e:
            logger.error(f"Error setting hash '{name}' field '{key}': {e}")
            return None

    def hget(self, name, key):
        """
        获取哈希表字段的值
        
        :param name: 哈希表名
        :param key: 字段
        :return: 字段值
        """
        try:
            value = self.redis.hget(name, key)
            logger.info(f"Get hash '{name}' field '{key}' with value '{value}'")
            return value
        except Exception as e:
            logger.error(f"Error getting hash '{name}' field '{key}': {e}")
            return None

    def lpush(self, name, *values):
        """
        向列表左侧插入数据
        
        :param name: 列表名
        :param values: 要插入的值
        :return: 执行结果
        """
        try:
            result = self.redis.lpush(name, *values)
            logger.info(f"LPush to list '{name}' values {values}")
            return result
        except Exception as e:
            logger.error(f"Error pushing to list '{name}': {e}")
            return None

    def lrange(self, name, start, end):
        """
        获取列表中的元素
        
        :param name: 列表名
        :param start: 起始索引
        :param end: 结束索引
        :return: 列表元素
        """
        try:
            values = self.redis.lrange(name, start, end)
            logger.info(f"LRANGE from list '{name}' from index {start} to {end} with values {values}")
            return values
        except Exception as e:
            logger.error(f"Error getting range from list '{name}': {e}")
            return None

    def pipeline(self):
        """
        创建 Redis 管道操作
        
        :return: 管道对象
        """
        return self.redis.pipeline()

    def scan(self, cursor=0, match=None, count=None):
        """
        使用 SCAN 命令遍历 Redis 键
        
        :param cursor: 游标
        :param match: 匹配模式
        :param count: 每次扫描的数量
        :return: (游标, 键列表)
        """
        try:
            cursor, keys = self.redis.scan(cursor, match=match, count=count)
            logger.info(f"SCAN with cursor {cursor}, found keys {keys}")
            return cursor, keys
        except Exception as e:
            logger.error(f"Error scanning keys: {e}")
            return cursor, []

    def close(self):
        """
        关闭 Redis 连接
        """
        try:
            self.redis.close()
            logger.info("Redis connection closed.")
        except Exception as e:
            logger.error(f"Error closing Redis connection: {e}")