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Python Python Collections (2016, retired 2019) Slices Slice Functions

Richard Li
Richard Li
9,751 Points
Posted by Richard Li
Richard Li
9,751 Points

First Slice Challenge Task 2 of 4: Why my code below is not right?

def first_and_last_4(item):
        a = item[:-5:-1]
        a.sort()
        return item[:4] + a

I am using this way to get familiar with steps and negative index. I know that item[:4] + item[-4:] will work too. But in REPL my above code have the same output as this one. So I don't know why it is not checked OK by the checker?

My guess is that .sort() messes up with the checker since the data it passed in may not be numeric or sorted?

1 Answer

Steven Parker
Steven Parker
229,744 Points
Steven Parker
Steven Parker
229,744 Points

It sounds like you already spotted part of the problem, you won't want to sort anything here.

But also take another look at your parameters for the "last four" slice. Unlike the "first four", you'll want to set the start position this time instead of the end position. And you won't want to reverse the order.

A little experimentation with slices in the workspace or your locally installed Python might be very helpful.