Stack_functions

stack = []
top = None

def listbox():
    print("1. Insert Data")
    print("2. Delete data")
    print("3. Display data")
    print("4. Exit")

def insert(stack,top):
    insele = int(input("Enter the number of element you want to enter:"))
    for i in range(insele):
        ele = input("Enter the element:")
        stack.append(ele)
    top = len(stack) - 1


def delete(stack, top):

    if stack == []:
        print("Underflow!")

    else:
        delele = int(input("Enter the number of elements you want to delete(LIFO):"))
        for i in range(delele):
            stack.pop()
        top = len(stack) - 1

        print("Operation accomplished!")

def display(stack,top):
    lst = []
    top = len(stack) - 1

    if stack == []:
        print("Underflow!")


    else:
        print(stack[top],"<---top")
        for i in range(0,top):
            lst.append(stack[i])
        lst.reverse()
        for i in lst:
            print(i)
        print("Operation accomplished!")


while True:
    listbox()
    choice = int(input("Enter your choice:"))

    if choice  == 1:
        insert(stack, top)

    if choice == 2:
        delete(stack, top)

    if choice == 3:
        display(stack,top)

    if choice == 4:
        break