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

Posted by Vincent Allport
Vincent Allport
3,317 Points

"Didn't get the right values for 'reverse_evens'"... but I do when I run it in console?

Hello,

I'm very confused as to why my answer here is not being accepted. When I run reverse_evens() in PyCharm, it returns [5, 3, 1] like it says it should. However when I try to submit it says it's not getting the right values. Can anyone help?

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

def first_and_last_4(iterable):
    return iterable[:4] + iterable [-4:]

def odds(iterable):
    return iterable[1::2]

def reverse_evens(iterable):
    return iterable[-1::-2]

2 Answers

Jennifer Nordell
seal-mask
STAFF
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher
Jennifer Nordell
.a{fill-rule:evenodd;}techdegree
Jennifer Nordell
Treehouse Teacher

Hi there! Your code does work but only in certain cases. Namely, it only works when the number of elements in the array is odd. Take a look at what happens when you do reverse_evens([1, 2, 3, 4, 5, 6]). I feel like you can get it now that you know why you might not be getting the correct result.

Hope this helps! :sparkles:

Vincent Allport
Vincent Allport
3,317 Points
Vincent Allport
Vincent Allport
3,317 Points

Ah great point! I figured it out with an if statement, thank you!