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 (Retired) Slices Slice Functions

Leen Leenaerts
PLUS
Leen Leenaerts
Courses Plus Student 2,367 Points

what's wrong with this?

?

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

def odds(a):
  length = len(a)
  for i in reversed(range(len(a)+1)):
    if a[i] %2 == 0:
      del a[i]
  return a

2 Answers

Martin Cornejo Saavedra
Martin Cornejo Saavedra
18,132 Points

The challenge asks for odd INDEX and not odd VALUE, this evaluation 'if a[i] %2 == 0:' is checking the value and not the index.

This is what worked for me:

def first_4(a):
    return a[:4]

def odds(a):
    return a[1::2]   #for odd index we start at index 1 (first odd index), 
                            #then jump 2 to the next odd index and so on.