针对永久不过期的key 批量设置过期时间

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()