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

Arthur Walton
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.a{fill-rule:evenodd;}techdegree
Arthur Walton
Python Web Development Techdegree Student 3,906 Points
Posted by Arthur Walton
.a{fill-rule:evenodd;}techdegree
Arthur Walton
Python Web Development Techdegree Student 3,906 Points

help with this splicing challenge

it wants me to move backwards through the list and only pull out the evens. I feel like [-1] is starting at the last spot on the list and [-2] means its moving back 2 spaces. which is the evens. is my logic incorrect? Thanks in advance.

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

def first_and_last_4(new_list):
    temp_list = new_list[:4]
    temp_list2 = new_list[-4:]
    temp_list.extend(temp_list2)
    return temp_list
def odds(new_list):
    return new_list[1::2]
def reverse_evens(new_list):
    return new_list[-1::-2]

1 Answer

mhjp
mhjp
20,372 Points

Depending on if the list is Even or Odd length your solution may not work. If you start from the beginning and slice then reverse the sliced list it should work.

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