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Python Python Collections (Retired) Slices Sorting Slices

what I am I doing wrong I get bummer Your messy_list doesn't have the right items

Now ,create a variable silly_list

lists.py
messy_list = [5, 2, 1, 3, 4, 7, 8, 0, 9, -1]

# Your code goes below here
clean_list = messy_list[:]
clean_list.sort()
silly_list = clean_list[8:-1:-3]

3 Answers

Your're close. Say we have a list of ints [0, 1, 2, 3, 4, 5, 6, 7, 8]; your code is telling python to start at the 8th index, which gives us the last item in the list (8 in this example). Your code also tells us to stop at -1, which also gives us the last item in the list, which is 8 again.

Try telling python to start with a negative index and don't forget that slices have defaults. [1 : : 3] would start at 1 and go to the end (length) of the list and give us every third item.

You may find this link helpful: (https://docs.python.org/3/tutorial/introduction.html)

Kenneth Love
STAFF
Kenneth Love
Treehouse Guest Teacher

Ian Keith's answer is a great one but you did find a mistake in the code challenge. I had messy_list in the error message where I should have had silly_list. Thanks for finding that!

messy_list = [5, 2, 1, 3, 4, 7, 8, 0, 9, -1]

Your code goes below here

clean_list = messy_list[:] clean_list.sort() messy_list = clean_list[10:-3]

Kenneth Love
Kenneth Love
Treehouse Guest Teacher

You're changing messy_list. You don't need to ever change messy_list.