Python: How to get a variable's value updated every call?

Question

Newbie question: How can I print a variable's current value at the moment when it is called, instead of getting its old value when it was first defined?

epoch = int(time.time()*1000)
print epoch
time.sleep(2)
print epoch # it should now be 2 seconds larger, but isn't.

Answer 1

You'd have to make a function for that. Something like this should suffice?

epoch = lambda: int(time.time()*1000)
print epoch()
time.sleep(2)
print epoch()

You could also encase this into a class and make a @property out of it, so that you can get a value without using brackets ()

Answer 2

You must to be confusing assignment of a variable with definition of a function. In your example, epoch is assigned only once, and will keep that value until you set it to something else. It won't change its value just because it was initially set as a result of a function call.

If you want a value that changes or updates, you'll have to make a function call either as @Rusty has described, or def a function.