I've been thinking lately about how perfect Redis would be for storing a

　　simple social graph. I posited that it would be relatively few lines of code,

　　and that it'd be clean code too. So here it is: a basic social graph built on Redis.

　　"""

　　class FriendGraph(object):

　　def __init__(self, ring):

　　self.ring = ring

　　# These keys are intentionally short, so as to save on memory in redis

　　self.FOLLOWS_KEY = 'F'

　　self.FOLLOWERS_KEY = 'f'

　　self.BLOCKS_KEY = 'B'

　　self.BLOCKED_KEY = 'b'

　　def follow(self, from_user, to_user):

　　forward_key = '%s:%s' % (self.FOLLOWS_KEY, from_user)

　　forward = self.ring.sadd(forward_key, to_user)

　　reverse_key = '%s:%s' % (self.FOLLOWERS_KEY, to_user)

　　reverse = self.ring.sadd(reverse_key, from_user)

　　return forward and reverse

　　怎样用Redis存储好友关系-python版

　　def unfollow(self, from_user, to_user):

　　forward_key = '%s:%s' % (self.FOLLOWS_KEY, from_user)

　　forward = self.ring.srem(forward_key, to_user)

　　reverse_key = '%s:%s' % (self.FOLLOWERS_KEY, to_user)

　　reverse = self.ring.srem(reverse_key, from_user)

　　return forward and reverse

　　def block(self, from_user, to_user):

　　forward_key = '%s:%s' % (self.BLOCKS_KEY, from_user)

　　forward = self.ring.sadd(forward_key, to_user)

　　reverse_key = '%s:%s' % (self.BLOCKED_KEY, to_user)

　　reverse = self.ring.sadd(reverse_key, from_user)

　　return forward and reverse

　　def unblock(self, from_user, to_user):

　　forward_key = '%s:%s' % (self.BLOCKS_KEY, from_user)

　　forward = self.ring.srem(forward_key, to_user)

　　reverse_key = '%s:%s' % (self.BLOCKED_KEY, to_user)

　　reverse = self.ring.srem(reverse_key, from_user)

　　return forward and reverse

　　def get_follows(self, user):

　　follows = self.ring.smembers('%s:%s' % (self.FOLLOWS_KEY, user))

　　blocked = self.ring.smembers('%s:%s' % (self.BLOCKED_KEY, user))

　　return list(follows.difference(blocked))

　　def get_followers(self, user):

　　followers = self.ring.smembers('%s:%s' % (self.FOLLOWERS_KEY, user))

　　blocks = self.ring.smembers('%s:%s' % (self.BLOCKS_KEY, user))

　　return list(followers.difference(blocks))

　　def get_blocks(self, user):

　　return list(self.ring.smembers('%s:%s' % (self.BLOCKS_KEY, user)))

　　def get_blocked(self, user):

　　return list(self.ring.smembers('%s:%s' % (self.BLOCKED_KEY, user)))