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Python Python Collections (2016, retired 2019) Lists Shopping List Take Three

Posted by Rudi Schenck
Rudi Schenck
16,642 Points

position -1 example

At the end of the video, Kenneth mentions that the code can be shortened a bit by setting position to -1 and always using append. I can't figure out what he means by this, can anyone post an example? Thanks!

2 Answers

ado
ado
1,719 Points
ado
ado
1,719 Points

I think he meant position = -1 instead of None then the if statements are no longer needed which shortens the program. I did try it but it's not adding the item to the end of the list. What worked for me is position = len(shopping_list) + 1.

try:
    position = abs(int(position))

except ValueError:
    position = len(shopping_list) + 1

shopping_list.insert(position-1, item)
Chris Guy
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Chris Guy
Python Web Development Techdegree Graduate 14,615 Points
Chris Guy
.a{fill-rule:evenodd;}techdegree seal-36
Chris Guy
Python Web Development Techdegree Graduate 14,615 Points

I was also confused by this part, but I did manage to shorten the function slightly and remove the need for 'None' like this:

    try:
        position = abs(int(position))
    except ValueError:
        shopping_list.append(new_item)
    else:
        shopping_list.insert(position - 1, item)