.delete returning number of deleted items instead of None.

Redis hints on the number of deleted items by returning it as a result of DEL command
127.0.0.1:6379[1]> del x y z
(integer) 2
127.0.0.1:6379[1]> del x y z
(integer) 0

django-redis could mimic that behaviour without breaking any existing functionality (as far as I see)

Also django docs aren't specific on what delete should return.
I think it's ok to allow deleting keys that are not present in redis (redis allows that) and returning the number of keys deleted just feels natural.