Assigning properties - YAPQ (Yet another python question)

Well, I have written a script to calculate damage for any object based on what hit it. And it almost works.

It grabs the current health value
It finds out what hit is
It subtracts from the health value based on what hit it.

Now is where I have the problem:
How do I get the integer value from python back into the property health?
(I have found out how to do a string value, but that is useless to me)

obj[‘health’] = newhealth

Make sure health is a int property

(2.5x this is, for 2.4x it obj.health).

It worked!!
Thanks very much