Memcached has some weird rules about its keys. Ignore them and you'll get an error like "MemcachedKeyCharacterError: Control characters not allowed". So install this.
Install django-memcachedkeys:
pip install django-memcachedkeys
Then use it in your settings file:
CACHES = {
'default': {
'BACKEND': 'django.core.cache.backends.memcached.MemcachedCache',
'LOCATION': '127.0.0.1:11211',
'KEY_PREFIX': 'whatever',
'KEY_FUNCTION': 'memcachedkeys.make_key',
}
}