I've used the Redis engine for this. Extremely simple, and lightweight.
Server side does:
import redis
r = redis.Redis() # Init
r.subscribe(['mychannel']) # Subscribe to "channel"
for x in r.listen():
print "I got message",x
Client side does:
import redis
r = redis.Redis() # Init
r.publish('mychannel',mymessage)
"messages" are strings (of any size). If you need to pass complex data structures, I like to use json.loads and json.dumps to convert between python dicts/arrays and strings -
"pickle" is perhaps the better way to do this for python-to-python communication, though JSON means "the other side" can be written in anything.
Now there are a billion other things Redis is good for - and they all inherently are just as simple.
