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

Posted by Tatiana Brittingham
Tatiana Brittingham
3,095 Points

reverse_evens runs OK on bash ---- does not pass here, why, world, why!! (>_<)

ran the function with both list as arg (as shown on ex) and passed a string in as well, both worked on bash:

[5, 3, 1]

i wonder what am i doing wrong.. thank you for looking into it!

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

def first_and_last_4(thing):
    a = thing[:4]
    b = thing[-4:]
    return a+b

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

def reverse_evens(another_thing):
    reversed_list = another_thing[::-1]
    return reversed_list[::2]

2 Answers

Stuart Wright
Stuart Wright
41,120 Points
Stuart Wright
Stuart Wright
41,120 Points

There is a slight difference between what your function does and what the challenge asks. The challenge asks you to "Return every item in the iterable with an even index...in reverse." What you have done is reverse the iterable, then return everything that is at an even index in the reversed iterable. These two processes return the same values when your iterable has an odd number of values, but try it with [1. 2, 3, 4, 5, 6]. The challenge wants [5, 3, 1] back, but your code returns [6, 4, 2].

Tatiana Brittingham
Tatiana Brittingham
3,095 Points
Tatiana Brittingham
Tatiana Brittingham
3,095 Points

Hi Stuart,

thanks for helping out, i pulled the even indexed values first and then reversed the copied list, so i reversed my original code's steps =^.^= many thanks!