example-2.py

#!/usr/bin/env python3
# example-2.py
# showing pass by reference 
var = 20 
print("Initial variable value and object number:")
print(var)
print(id(var))

def pass_by_reference():
    global var
    print("Initial ")
    print(id(var))
    var += 20
    print(var)
    print(id(var))

pass_by_reference()
print(var)
print(id(var))

def pass_by_value(var):
    total = var
    total = total + 20
    print(total)
    print(id(total))
    return total

pass_by_value(var)
print(var)
print(id(var))