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

Posted by Darrin Spell Jr
.a{fill-rule:evenodd;}techdegree
Darrin Spell Jr
Full Stack JavaScript Techdegree Student 10,303 Points

Can someone explain to me what exactly I am doing wrong in this challenge. It's pretty tricky.

I am having a hard time with task 2 with first_4 and last_4

slices.py 
def first_4(string):
    return string[:4]

def first_and_last_4(numbers):
    numbers = list(range(20))
    first_4 = numbers[:4]
    pre_4 = numbers[-1:-5:-1]
    last_4 = pre_4[::-1]
    all_4 = first_4 + last_4
    print(all_4)

1 Answer

Steven Parker
Steven Parker
229,644 Points
Steven Parker
Steven Parker
229,644 Points

You're working too hard! You already know how to get the first 4 with one line of code. Getting the last 4 is very similar (just with different slice arguments). Then it's just a matter of sticking them together and returning (and no lists or ranges needed).

Darrin Spell Jr
.a{fill-rule:evenodd;}techdegree
Darrin Spell Jr
Full Stack JavaScript Techdegree Student 10,303 Points

I don't know how to stick two different slices together.

Steven Parker
Steven Parker
229,644 Points
Steven Parker
Steven Parker
229,644 Points

Joining strings is done with concatenation, using the plus-sign operator ("+").