Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Introducing Lists Build an Application Add Items

Posted by Ian Gilbert
Ian Gilbert
980 Points

Can't get line 9 to function.

So I am trying to follow the video, in order to make sure I get this stuff through my semi permeable sandstone skull I often repeat everything over and over... this time though I can't get the code on line 9 // print("Added! There are {} items".format(len(shopping_list))) \ to run... I have copied the whole code below is anyone able to tell me where I went off the rails?

Create a new empty shopping list named shopping_list

shopping_list = []

Create a function named add_to_list that declares parameter named item

def add_to_list(item): # Add the item to the list shopping_list.append(item) # Notify user that the item was added, and state the nymber of items in the list currently print("Added! There are {} 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. """)

show_help()

while True: new_item = input ("> ")

if new_item == "DONE":
    break
elif new_item=='HELP':
    show_help()
    continue

    # Call add_to_list as a argument.
    add_to_list(new_item)
Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

Try formatting your code so the spacing shows up (in Python, indentation is critical).
Use the instructions for code formatting in the Markdown Cheatsheet pop-up below the "Add an Answer" area. :arrow_heading_down:
Or watch this video on code formatting.

1 Answer

highlandcow
highlandcow
7,352 Points
highlandcow
highlandcow
7,352 Points

I had a similar issue. I was able to get the code to behave as expected by introducing an "else" condition before calling add_to_list:

while True:
  new_item = input("> ")

  if new_item == 'DONE':
    break
  elif new_item == 'HELP':
    show_help()
    continue
  else:
    add_to_list(new_item)
highlandcow
highlandcow
7,352 Points
highlandcow
highlandcow
7,352 Points

Alternatively, if you don't want to add 'else', alter your indentation so "add_to_list(new_item)" is in line with your if and elif statements. Like so:

while True:
  new_item = input("> ")

  if new_item == 'DONE':
    break
  elif new_item == 'HELP':
    show_help()
    continue
  elif new_item == 'SHOW':
    show_list()
    continue

  add_to_list(new_item)