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

Mattan Yedidya
Mattan Yedidya
1,084 Points
Posted by Mattan Yedidya
Mattan Yedidya
1,084 Points

What is wrong with my reverse evens function? I tested it in workspaces and it works...

Look at code

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

def first_and_last_4(itr):
    temp = itr[:4]
    temp += itr[-4:]
    return  temp

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

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

1 Answer

Steven Parker
Steven Parker
231,236 Points
Steven Parker
Steven Parker
231,236 Points

You probably only tested on one sample and got lucky. Based on the length of the list, this code will work 50% of the time.

To make it work every time, you will either need to compute the starting point based on the length of the list; or you could slice twice, once to get the even indices and again to reverse it.