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Luis Miguel Hernandez
4,266 PointsI test in my local enviroment and works!
Help!
def first_4(listas):
return listas[:4]
def first_and_last_4(numbers):
first = first_4(numbers)
last = numbers[-4:]
return first + last
def odds(numbers):
return numbers[1::2]
def reverse_evens(numbers):
return numbers[::-2]
2 Answers
Steven Parker
231,007 PointsYou must have been testing only with lists having an odd number of elements. As you noticed, it works with those. But otherwise it will return "reverse odds" instead.
To always return reverse evens, you'll need to compute the starting position based on the list size, or extract the even indexes first and then reverse them in a separate step.
andhika pratikto
995 Pointsdef first_4(iterable):
return iterable[:4]
def first_and_last_4(iterable):
return first_4(iterable) + iterable[-4:]
def odds(iterable):
return iterable[1::2]
def reverse_evens(iterable):
return iterable[::2][::-1]```
Luis Miguel Hernandez
4,266 PointsLuis Miguel Hernandez
4,266 PointsCan you explain me with code? This is new for me.
Steven Parker
231,007 PointsSteven Parker
231,007 PointsWell, if you use the 2nd method, you can get just the even indexes using a slice with a step of 2, then reverse that using one with a step of -1:
numbers[::2][::-1]Luis Miguel Hernandez
4,266 PointsLuis Miguel Hernandez
4,266 PointsPerfect!!!!!! Thank you!