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

Pratham Patel
Pratham Patel
4,976 Points
Posted by Pratham Patel
Pratham Patel
4,976 Points

Can I get some help with this code challenge

I don't understand what it means to place them in a single value

slices.py 
def first_4(a):
    return a[0:4]
def first_and_last_4(b):
    return list(b[0:4]) + list(b[-1:-5])

1 Answer

Kenneth Love
STAFF
Kenneth Love
Treehouse Guest Teacher
Kenneth Love
Kenneth Love
Treehouse Guest Teacher

You're close. But -1:-5 would be a backwards move. You're currently giving it a positive step, though (the default value of 1). So Python is trying to move from -1 to -5 by adding 1 to the index, which it can't do.

Do you remember how to do negative indexes? What's the negative index for the item 4 indexes from the end?