Queues

#Queue



data=""
myQueue=["a","b","c","d","","",""]
pointerTop=3
pointerBottom=0
queueMax=len(myQueue)-1


def push():
    global myQueue
    global pointerTop
    global pointerBottom
    global data
    global queueMax

    data=input("Enter your Data!: ")
    if pointerTop==queueMax:
        print("Sorry this queue is full!")
    else:
        pointerTop=pointerTop+1
        myQueue[pointerTop]=data
        print("Data Saved!")
        print(myQueue)


def pop():
    global myQueue
    global pointerTop
    global pointerBottom
    global data
    global queueMax

    myQueue[pointerBottom]=""
    print("Data Deleted")
    pointerBottom=pointerBottom+1
    print(myQueue)



while 1:
    print(pointerTop,pointerBottom)
    choice=input("PUSH or POP?: ")
    if choice=="POP":
        pop()
    elif choice=="PUSH":
        push()
    else:
        print("INVALID INPUT")

    print("===================================")