Secure scripts variables

[Florian Lindner]

Hello,
given the following situation:

I have a script which is readable and executable by a user, but not
writable.
The users executes the scripts, it reads in a value and based on this value
it computes a result and stores it in a variable.
Can the user read out the value of this variable? If yes, can he be
prevented to do so?

(It's a ordinary user on a Linux system with access to the python
interpreter.)

(Of course: He could just copy the script to a file he has write access and
modify it to print the result. It's a theoretical situation.)

Thanks,
Florian