Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

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

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

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
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?