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Python

Posted by Jenna Rowan
Jenna Rowan
2,721 Points

Done improperly being added to the list

I'm early in the video I'm working on, but I'm having an issue that I can't figure out.

Here is my code:

list = []
item = ''

while item != 'DONE':
    item = input("What item do you need to shop for?\n")

    if item == 'SHOW':
        print(list)
    else:
        list.append(item) 

print(list)

When I put 'DONE' it stops the loop and shows me the list, as it should, but it also adds itself as the last item, which it shouldn't be doing. I don't understand why item is 'DONE' is not causing it to skip that entire code block and go right to printing the list.

1 Answer

Ryan S
Ryan S
27,276 Points

Hi Jenna,

The reason it still appends 'DONE' to the list, is because the while condition is only checked at the beginning of each repetition of the loop. When you enter 'DONE', it will still run the rest of the code until the loop restarts and checks the while condition again. At this point it will evaluate to False and stop the loop right there.

If you want to exit the loop while it's running, you will need to make use of the break keyword. I'm not sure which point you are at in the course, but you will be introduced to it soon.

Jenna Rowan
Jenna Rowan
2,721 Points

That makes perfect sense. Thank you!