Shopping List Python Issue

#Functions
#Help Function
def help():
    print("""
    These are the things you can do
    Typing DONE let's you finalize your list
    Typing SHOW let's you show your current list
    """)
#Show List Function
def show_list(shopping_list):
    print(shopping_list)
#Add items to list Function
def add_to_list(shopping_list):
    global new_item
    new_item = input("> ")
    shopping_list.append(new_item)
    print("{} Added to your list. Your list now has {} items".format(new_item,len(shopping_list)))

#Application Function
def shopping_app():
    while True:
        add_to_list(shopping_list)
        if new_item == 'SHOW':
            show_list(shopping_list)
            continue
        elif new_item == 'HELP':
             help()
             continue
        else:
            if new_item == 'DONE':
                break
    for item in shopping_list:
        print(item)
#Start of application
shopping_list = []
print("What do you need to shop for today?")
print("You can finish your list by typing DONE")
shopping_app()