Python Python Collections Slices Slice Functions

Dain Lewis
Dain Lewis
831 Points

My code is not being accepted, not sure exactly why.

The final part, at the bottom of my code, is where I'm having the trouble. I think my code works, it reverses the order, then takes out the oddly indexed values. I found that if I tried to do them both in one go, whether it did even or odd indices depended on the total number of items in the iterable.

I added the final bit equating iterable with reversed list so that in the end it would return the same iterable being passed into the function, just in case it was checking for that.

Thank you
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):
    reverse_list = iterable[::-1]
    reversed_evens = reverse_list[::2]
    iterable = reversed_evens[::]
    return iterable

2 Answers

Cheo R
Cheo R
36,139 Points
In [4]: test2 = [1, 2, 3, 4, 5, 6]

In [5]: reverse_evens(test2)
Out[5]: [6, 4, 2]

In [6]: test3 = [1, 2, 3, 4, 5, 6, 7]

In [7]: reverse_evens(test3)
Out[7]: [7, 5, 3, 1]

Your code works for lists are odd but fails for when lists are even. I suspect tests include even iteratables.

Dain Lewis
Dain Lewis
831 Points

Ah I see, I thought I had tested that. Thank you!