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Python Introducing Lists Build an Application Display the List

Miles Welch
Miles Welch
628 Points
Posted by Miles Welch
Miles Welch
628 Points

Tried code as entered, keep getting different results

create a new empty list called shopping_list

shopping_list = []

create a function named add_to_list that declares a parameter named item

def add_to_list(item): # add the item to the list shopping_list.append(item) # notify user of total items in list print("Added! List has {} items.".format(len(shopping_list)))

def show_help(): 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 the whole list. """) print(show_help())

def show_list(): for item in shopping_list: print("Here's your list:") for item in shopping_list: print(item)

while True: new_item = input("> ") # prompts for new data to be added to list

if new_item == 'DONE':  # terminates prompt when DONE is entered
    break               # breaks the loop
elif new_item == 'HELP':
    show_help()
    continue
elif new_item == 'SHOW':
    show_list()
    continue

    # call add_to_list with new_item as an argument
add_to_list(new_item)

print(show_list())

the word "none" keeps showing up in my lists, and my list repeats twice when I use "DONE" command

Steven Parker
Steven Parker
243,861 Points
Steven Parker
Steven Parker
243,861 Points

Code should be properly formatted. (most important for Python!). Take a look at these videos about Posting a Question, using Markdown formatting to preserve the code's appearance, and particularly this one about sharing a snapshot of your workspace.

1 Answer

Steven Parker
Steven Parker
243,861 Points
Steven Parker
Steven Parker
243,861 Points

The unformatted lines make it hard to be sure, but I think I see two issues:

  1. The function show_list() is defined having two loops, but it should only have the second one.
  2. On the last line, show_list() should be called directly. By printing it, you get the extra "None" since the function itself does not return any value.

And while you didn't mention it, the same thing (getting a "None" at the end) happens when you print show_help() instead of calling it directly.