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Python Python Collections (2016, retired 2019) Lists Shopping List Take Three

nicole lumpkin
PLUS
nicole lumpkin
Courses Plus Student 5,328 Points

Global var new_item vs. local var item

Why wouldn't we assign the function add_to_list(item) with the positional argument of new_item(I hope this verbiage is correct)? Please refer to the code below for context!

import os

shopping_list = []


def clear_screen():
    os.system("cls" if os.name == "nt" else "clear")



def show_help():
    clear_screen()
    # print out instructions on how to use the app
    print("What should we pick up at the store?")
    print("""
Enter 'DONE' to stop adding items.
Enter 'HELP' for this help.
Enter 'SHOW' to see your current list.
""")

def show_list():
    clear_screen()
    print("Here's your list:")

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

    print("-" * 10)

def add_to_list(item):
    show_list()
    if len(shopping_list):
        position = input("Where should I add {}?\n"
                         "Press ENTER to add to the end of the list\n"
                         "> ".format(item))
    else:
        position = 0


    try:
        position = abs(int(position))
    except ValueError:
        position = None
    if position is not None:
        shopping_list.insert(position-1, item)
    else: 
        shopping_list.append(new_item)

    show_list()

show_help()

while True:
    # ask for new items
    new_item = input("> ")

    # be able to quit the app
    if new_item.upper() == 'DONE' or new_item.upper() == 'QUIT':
        break
    elif new_item.upper() == 'HELP':
        show_help()
        continue
    elif new_item.upper() == 'SHOW':
        show_list()
        continue
    else:
        add_to_list(new_item)

show_list()

First we .format() using item, then we .insert() using item, but then we .append() using new_item...Why??