Value by reference issue

[javaben]

I've run across an issue with trying to copy an int argument for later use in the program. I realized the int that was copied is changing the value of the original argument; using id(val) and the copy id(valCopy), I can see that they have the same address. This isn't what I was expecting, as this is a simple int, not a list or similar. So, I did import copy, and used both copy.copy and copy.deepcopy, and all have the same result. I found that by modifying the copy, using +=1, then I get a new location, and no longer change the underlying.

I don't see any reference to having to do it this way, so I'm confused.
I'm using python version Python 3.8.10 (default, Jun 2 2021, 10:49:15) , but have also tried it on 3.10.x with same results.

import copy

def a(val):
    newVal1 = val
    print("values:    val: ", val,     " newVal:", newVal1)
    print("addresses: val: ", id(val), " newVal:", id(newVal1))

    newVal2 = copy.copy(val)
    print("values:    val: ", val,     " newVal:", newVal2)
    print("addresses: val: ", id(val), " newVal:", id(newVal2))

    newVal3 = copy.deepcopy(val)
    print("values:    val: ", val,     " newVal:", newVal3)
    print("addresses: val: ", id(val), " newVal:", id(newVal3))


    newVal1 += 1

    print("values:    val: ", val,     " newVal:", newVal1)
    print("addresses: val: ", id(val), " newVal:", id(newVal1))

def main():
    a(1)

if(__name__ == '__main__'):
    main()

Output:
values:    val:  1  newVal: 1
addresses: val:  9476448  newVal: 9476448
values:    val:  1  newVal: 1
addresses: val:  9476448  newVal: 9476448
values:    val:  1  newVal: 1
addresses: val:  9476448  newVal: 9476448
values:    val:  1  newVal: 2
addresses: val:  9476448  newVal: 9476480