adding two items instead of one in program

Question

whenever i add an item to the list it is added twice. I cant understand why. 
import os
shopping_list = []
def clear_screen():
    os.system("cls" if os.name == "nt" else "clear")
def showhelp():
    clearscreen()
    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 addtolist(item):
    showlist()
    if len(shoppinglist):
        position = input("Where should I add {}?
"
                         "Press ENTER to add to the end of the list
"
                         "> ".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

shopping_list.append(new_item)
print("Added! List has {} items.".format(len(shopping_list)))
def showlist():
    clearscreen()
    print("Here's your list:")
index = 1
for item in shopping_list:
    print("{}. {}".format(index, item))
    index += 1

print("-"*10)
show_help()
while True:
    new_item = input("> ")
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()

Steven Parker · Accepted Answer

It's hard to read unformatted code, but the issue seems to happen on these lines:
```py
if position is not None:
    shoppinglist.insert(position-1, item)   # this line may add the item the first time
else:
    shoppinglist.append(newitem)           # ...or this one will
showlist
shoppinglist.append(newitem)               # then this line adds it again
```
In future questions, use the instructions for code formatting in the Markdown Cheatsheet pop-up below the "Add an Answer" area. :arrowheadingdown:
   Or watch this video on code formatting (https://teamtreehouse.com/library/code).

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Movrard Herard

Movrard Herard

adding two items instead of one in program

1 Answer

Steven Parker

Steven Parker