From the django docs:
After installing Memcached itself, you\'ll need to install a memcached binding. There are several python memcached bindings availabl
Detailed explanation here http://ilian.i-n-i.org/caching-websites-with-django-and-memcached/
The link above includes explanations for how to install Memcached on Ubuntu, how to configure it as cache engine in your Django project and how to use it.
Just do pip install python-memcached
and you should be good.
As for installing memcached itself, it depends on the platform you are on.
brew install memcached
sudo apt-get install memcached
On OS X/Linux, just run memcached
in the command line.