# Change local copy of integer
def fun1(tempNum):
    tempNum = tempNum * 2
    print("tempNum %d" %tempNum)

# Change local copy of integer but the current value of 
# local passed back to caller.
def fun2(tempNum):
    tempNum = tempNum * 2
    print("tempNum %d" %tempNum)
    return(tempNum)

# Create a new list and return reference to new list
def fun3():
    aList = ["a","b","c"]
    return(aList)

# Unnecessary to pass list as parameter and return
def fun4(aList):
    aList = ["X","Y","Z"]
    return(aList)

# At start we have reference to list in start(), "pass by
# reference" for lists in Python
def fun5(tempList):
     # With the reference we can the list in start()
     tempList[1] = 7  
     tempList[2] = 13

# At start we have reference to list in start(), "pass by
# reference" for lists in Python
def fun6(tempList):
     # This creates a new list and address of list in 
     # start() lost because it's overwritten with the list
     # that is local to fun6().
     # JT: be careful that you don't do this, likely it is
     # a logic error in your program.
     tempList = [3,2,1]
     print("Displays only local list", end =" ")
     print(tempList)

def fun7(localReference):
    aList = localReference
    size = len(localReference)
    for i in range (0,size,1):
        aList.append(localReference[size-i-1])


def start():
     aNum = 8
     aList = [1,2,3]

     print(aNum)
     print("In effect pass by value for integers in Python")
     fun1(aNum)
     print(aNum)
     print("With anything but lists must return changes")
     aNum = fun2(aNum)
     print(aNum)     
     input("Hit enter to continue")

     print(aList)
     aList = fun3()
     print(aList)
     aList = fun4(aList)
     print(aList)
     fun5(aList)
     print("List before fun6 ", end = " ")
     print(aList)
     fun6(aList)
     print("List after fun6 ", end = " ")
     print(aList)

     aList = [1,2,3]
     print("List reference before fun7()", end = "\t")
     print(aList)
     fun7(aList)
     print("List reference after fun7()", end = "\t")
     print(aList)

     aList = [1,2,3]



start()