Keep persistent variables in memory between runs of Python script

Is there any way of keeping a result variable in memory so I don’t have to recalculate it each time I run the beginning of my script?
I am doing a long (5-10 sec) series of the exact operations on a data set (which I am reading from disk) every time I run my script.
This wouldn’t be too much of a problem since I’m pretty good at using the interactive editor to debug my code in between runs; however sometimes the interactive capabilities just don’t cut it.

Python Django Global Variables

I’m looking for simple but recommended way in Django to store a variable in memory only. When Apache restarts or the Django development server restarts, the variable is reset back to 0. More specifically, I want to count how many times a particular action takes place on each model instance (database record), but for performance reasons, I don’t want to store these counts in the database. I don’t care if the counts disappear after a server restart. But as long as the server is up, I want these counts to be consistent between the Django shell and the web interface, and I want to be able to return how many times the action has taken place on each model instance.