In running shopping_list_3.py exercise, I receive error: insert() takes exactly 2 arguments(1 given)

#N Bogaard --Shopping List 3 -- instructor Kenneth Love in Python Collections

shopping_list = []

def show_help():
    print("\nSeparate each item with a comma.")
    print("Type DONE to quit, SHOW to see the current list, and HELP to get this message.")

def show_list():
    count = 1
    for item in shopping_list:
        print("{}: {}".format(count, item))
        count += 1

print ("Give me a list of things you want to shop for.")
show_help()

while True:
    new_stuff = input("> ")

    if new_stuff == "DONE":
        print("\nHere's your list:")
        show_list()
        break
    elif new_stuff == "HELP":
        show_help()
        continue
    elif new_stuff == "SHOW":
        show_list()
        continue
    else:
        new_list = new_stuff.split(",")
        index = input("Add this at a certain spot? Press enter for the end of the list, "
                      "or give me a number. Currently {} items are in the list.".format(len(shopping_list)))
        if index:
          spot = int(index) - 1
          for item in new_list:
            shopping_list.insert(item.strip())
            spot += 1
        else:    
          for item in new_list:
            shopping_list.append(item.strip())