As far as I know, ElastiCache cluster is just a bunch of memcached servers, so you need to give your memcached client the list of all of your servers and have the client do the relevant load balancing.
For Python, you have a couple of options:
pylibmc - which is a wrapper around libmemcached - one of the best and fastest memcached clients there is
python-memcached - a native Python client - very basic, but easy to work with, install and use
They haven't provided a client yet in python to deal with the new auto-discovery feature unfortunately.