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

Chaltu Oli
Chaltu Oli
4,915 Points
Posted by Chaltu Oli
Chaltu Oli
4,915 Points

I can't get the last one to work?

I can't get to work?

slices.py 
def first_4(item1):
    return item1[:4]
def first_and_last_4(single):
    return first_4(single) + single[-4:]
def odds(index):
    return index[1::2]
def reverse_evens(sing):
    return sing[-1::-2]

2 Answers

Steven Parker
Steven Parker
229,732 Points
Steven Parker
Steven Parker
229,732 Points

Your method will work half of the time, based on the number of items. But in the other cases it will return reverse odds instead.

To always return reverse evens, there's two basic strategies:

  • compute the starting position based on the list size
  • extract the even index values first, then reverse them

Either one will pass the challenge when implemented correctly.

Grigorij Schleifer
Grigorij Schleifer
10,365 Points
Grigorij Schleifer
Grigorij Schleifer
10,365 Points

Hi Steven, this is a great way to explain it!!!!!

Grigorij Schleifer
Grigorij Schleifer
10,365 Points
Grigorij Schleifer
Grigorij Schleifer
10,365 Points

Hey Ulfina, check this stack overflow link. It's quite good.