在使用 Redis、Codis 时，我们经常需要做一些批量操作，通过连接数据库批量对 key 进行操作：
常见的场景：
1.批量扫描key
2.获取info信息
3.获取client信息
4.设置配置参数
5.redis定期扫描
批量初始化redis 客户端：
1 from redis import Redis 2 def setExpiredKeys(): 3 try: 4 if redis_pass == 'none': 5 redisclient = Redis(host=redis_host, port=redis_port,db=0) 6 else: 7 redisclient = Redis(host=redis_host, port=redis_port, password=redis_pass) 8 # 初始化 redis 客户端：redisclient 9 # info = redisclient.info() 10 11 except Exception as e: 12 raise e 13 if __name__ == '__main__': 14 redis_host = '39.196.9.99' 15 redis_port = 6001 16 redis_pass = '123456' 17 setExpiredKeys()
详解：
1. Redis.info() 源代码：
返回结果：包含相关信息的字典
1 def info(self, section=None): 2 """ 3 Returns a dictionary containing information about the Redis server 4 """ 5 if section is None: 6 return self.execute_command('INFO') 7 else: 8 return self.execute_command('INFO', section)
1 info = redisclient.info() # 返回 Redis Server Info的所有信息 2 info = redisclient.info('Keyspace') # 返回指定section的信息
1 output: 2 {'db0': {'keys': 20005, 'expires': 5322, 'avg_ttl': 84036169}}
2. Redis.get() 源代码
获取key的value
1 def get(self, name): 2 """ 3 Return the value at key ``name``, or None if the key doesn't exist 4 """ 5 return self.execute_command('GET', name)
1 info = redisclient.get('name') # 返回value：'Jack'
3. Redis.client_list() 源代码
1 def client_list(self, _type=None): 2 """ 3 Returns a list of currently connected clients. 4 If type of client specified, only that type will be returned. 5 :param _type: optional. one of the client types (normal, master, 6 replica, pubsub) 7 """ 8 "Returns a list of currently connected clients" 9 if _type is not None: 10 client_types = ('normal', 'master', 'replica', 'pubsub') 11 if str(_type).lower() not in client_types: 12 raise DataError("CLIENT LIST _type must be one of %r" % ( 13 client_types,)) 14 return self.execute_command('CLIENT LIST', b'TYPE', _type) 15 return self.execute_command('CLIENT LIST')
1 info = redisclient.client_list() # 获取client列表
1 output： 2 [ 3 {'id': '1319', 'addr': '127.0.0.1:48670', 'fd': '7', 'name': '', 'age': '5263', 'idle': '444', 'flags': 'N', 'db': '0', 'sub': '0', 'psub': '0', 'multi': '-1', 'qbuf': '0', 'qbuf-free': '0', 'obl': '0', 'oll': '0', 'omem': '0', 'events': 'r', 'cmd': 'client'}, 4 {'id': '1329', 'addr': '113.46.252.27:54863', 'fd': '8', 'name': '', 'age': '1', 'idle': '0', 'flags': 'N', 'db': '0', 'sub': '0', 'psub': '0', 'multi': '-1', 'qbuf': '0', 'qbuf-free': '32768', 'obl': '0', 'oll': '0', 'omem': '0', 'events': 'r', 'cmd': 'client'} 5 ]
4. Redis.config_ 配置参数相关源代码：
1 def config_get(self, pattern="*"): 2 "Return a dictionary of configuration based on the ``pattern``" 3 return self.execute_command('CONFIG GET', pattern) 4 5 def config_set(self, name, value): 6 "Set config item ``name`` with ``value``" 7 return self.execute_command('CONFIG SET', name, value) 8 def config_rewrite(self): 9 "Rewrite config file with the minimal change to reflect running config" 10 return self.execute_command('CONFIG REWRITE')
举例：内存扩容
1 info = redisclient.config_get('maxmemory') 2 info1 = redisclient.config_set('maxmemory','100MB') 3 info2 = redisclient.config_rewrite()
1 output： 2 info : {'maxmemory': '104857600'} 3 info1: True 4 info2: b'OK'
5. Redis.scan_iter() 源代码
1 def scan_iter(self, match=None, count=None): 2 """ 3 Make an iterator using the SCAN command so that the client doesn't 4 need to remember the cursor position. 5 ``match`` allows for filtering the keys by pattern 6 ``count`` allows for hint the minimum number of returns 7 """ 8 cursor = '0' 9 while cursor != 0: 10 cursor, data = self.scan(cursor=cursor, match=match, count=count) 11 for item in data: 12 yield item
1 redisclient.scan_iter(count=500): # 每次扫描并返回500个key，
以上是Redis模块中常用的几个函数，能够有效提高工作效率！