问题需求：
　　redis内存暴增，后来发现有很多设置永久不过期。

解决：查找出来之后针对前缀批量设置过期时间 （过期时间与开发沟通 保证服务不受影响）

 来源于网上杨一的代码   正好解决了我遇到的问题 在这里记录一下。 

1 # encoding: utf-8

 import redis

 import random

 import string

 import time

 pool = redis.ConnectionPool(host='127.0.0.1', port=6379, password="", db=0)

 r = redis.Redis(connection_pool=pool)

 def random_str():

     return ''.join(random.choice(string.ascii_letters + string.digits) for _ in range(7))

 def init_keys():

     start_time = time.time()

     for i in xrange(0, 20):

         key_name = 'dba_'+str(i)

         value_name = random_str()

         r.set(key_name, value_name)

     print 'initial keys successfully,use time:', time.time() - start_time

 def del_keys_without_pipe():

     start_time = time.time()

     result_length = 0

     for key in r.scan_iter(match='rawdata_lastStatus_0015000200*', count=1000):

         r.delete(key)

         result_length += 1

     print "normal ways end at:", time.time() - start_time

     print "normal ways delete numbers:", result_length

 def del_keys_with_pipe():

     start_time = time.time()

     result_length = 0

     pipe = r.pipeline()

     for key in r.scan_iter(match='rawdata_*_otherTrades', count=1000):

         pipe.expire(key,120)

         result_length += 1

         if result_length % 1000 == 0:

             pipe.execute()

         time.sleep(1)

     pip_time = time.time()

     print "use pipeline scan time ", time.time() - start_time

     pipe.execute()

     print "use pipeline end at:", time.time() - pip_time

     print "use pipeline ways delete numbers:", result_length

 def main():

 #    init_keys()

 #    del_keys_without_pipe()

 #    init_keys()

     del_keys_with_pipe()

 if __name__ == '__main__':

     main()