Python Web Scraping - Second Edition

Redis cache implementation

Now we are ready to build our cache on Redis using the same class interface as the earlier DiskCache class:

import jsonfrom datetime import timedelta from redis import StrictRedisclass RedisCache:     def __init__(self, client=None, expires=timedelta(days=30), encoding='utf-8'):         # if a client object is not passed then try         # connecting to redis at the default localhost port         self.client = StrictRedis(host='localhost', port=6379, db=0)             if client is None else client         self.expires = expires        self.encoding = encoding    def __getitem__(self, url):         """Load value from Redis for the given URL"""         record = self.client.get(url)         if record:             return json.loads(record.decode(self.encoding))        else:  raise KeyError(url + ' does not ...