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

Joseph Ferrero
Joseph Ferrero
1,308 Points

No idea why my code is working, I have tested it and it worked fine.

This seems to be ok, but its not passing, what am I doingg wrong?

def first_4(iterable):

def first_and_last_4(iterable):
    return iterable[:4] + iterable[-4:]

def odds(iterable):

def reverse_evens(iterable):

1 Answer

Brian Polonia
Brian Polonia
25,139 Points

Here is my answer, it is the same as yours except I added a conditional to the last function (I'll explain below) and I removed the parenthesis from the return statements.

def first_4(iterable):  # your original code - parenthesis on return statement
    return iterable[:4]

def first_and_last_4(iterable):  # your original code
    return iterable[:4] + iterable[-4:]

def odds(utterable):  # your original code - parenthesis on return statement
    return iterable[1::2]

# Since we want to return only the even indices going backwards
# we check if the length of the iterable is even because this affects 
# whether the starting point should be [-2] or [-1] determining that
# your starting index is even. Then, as you were doing already, use a -2 step.

def reverse_evens(iterable):
    if len(iterable) % 2 == 0:
        return iterable[-2::-2]
    return iterable[-1::-2]

I hope this helps.

  • BP