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Python Python Basics (2015) Shopping List App Refactor

Paul Landrum
Paul Landrum
508 Points
Posted by Paul Landrum
Paul Landrum
508 Points

Def main():

Need a tip on this challenge. I defined main(): function and indented everything below it. Looked on community for tips, but didn't see anything that helped me get through. Thanks.

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():

    show_help()

    # make a list to hold onto our items
    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
    add_to_list(shopping_list, new_item)

    show_list(shopping_list)

3 Answers

andren
andren
28,558 Points
andren
andren
28,558 Points

The problem is that you have not indented the code that belongs to the while loop. All of the code that belongs to it need to be indented to be one level deeper than the while loop declaration, just like the code that belongs to the function needs to be.

Like this:

def main():

    show_help()

    # make a list to hold onto our items
    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
        add_to_list(shopping_list, new_item)

    show_list(shopping_list)
Stephen Akinkugbe
Stephen Akinkugbe
8,615 Points
Stephen Akinkugbe
Stephen Akinkugbe
8,615 Points

The problem is the add_to_list funtion that wasn't nested into the last show_list function. The nesting has to take place since add_to_list returns a shopping_list as value

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()

make a list to hold onto our items

   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
      show_list(add_to_list(shopping_list, new_item))
Stephen Akinkugbe
Stephen Akinkugbe
8,615 Points
Stephen Akinkugbe
Stephen Akinkugbe
8,615 Points

The problem is the add_to_list funtion that wasn't nested into the last show_list function. The nesting has to take place since add_to_list returns a shopping_list as value

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()

make a list to hold onto our items

   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
      show_list(add_to_list(shopping_list, new_item))