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Python Python Basics (2015) Shopping List App Refactor

Clayton McDaniels
Clayton McDaniels
5,788 Points
Posted by Clayton McDaniels
Clayton McDaniels
5,788 Points

Why is this not working for the challenge?

I had to google this (if name == 'main': main()) because it was not covered.

shopping_list.py 
def show_help():
    # 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(shopping_list):
    # print out the list
    print("Here's your list:")

    for item in shopping_list:
        print(item)

def add_to_list(shopping_list, new_item):
    # add new items to our list
    shopping_list.append(new_item)
    print("Added {}. List now has {} items.".format(new_item, len(shopping_list)))
    return shopping_list

def main():
    shopping_list = []
    show_help()
    while True:
        # ask for new items
        new_item = input("> ")

        # be able to quit the app
        if new_item == 'DONE':
            break
        elif new_item == 'HELP':
            show_help()
            continue
        elif new_item == 'SHOW':
            show_list(shopping_list)
            continue
        else:
            add_to_list(shopping_list, new_item)
if __name__ == '__main__':
    main()

1 Answer

Katie Wood
Katie Wood
19,141 Points

Hello there,

You don't need to add any code to the bottom for this challenge - all it wants you to do is add the "def main():" line on line 22 and indent all the code below that. If you just delete those last two lines, it'll throw an error about the show_help() function - I believe that is because show_help() is above the shopping list in the original code, so that is what it's expecting. For me, it passes if you move show_help() back above the declaration for the shopping list, in addition to removing those last two lines.

Final code would look like this:

def show_help():
    # 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(shopping_list):
    # print out the list
    print("Here's your list:")

    for item in shopping_list:
        print(item)

def add_to_list(shopping_list, new_item):
    # add new items to our list
    shopping_list.append(new_item)
    print("Added {}. List now has {} items.".format(new_item, len(shopping_list)))
    return shopping_list

def main():
    show_help()
    shopping_list = []

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

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

One important thing to know about challenges is that it's running validation code in the background - if you have a method like main(), you don't actually need to call it in your code unless the challenge asks you to (because it will usually do that on its own when it checks).

Hope this helps!