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JeanMartin Ghecea
5,770 PointsWhy doesn't my function work as I wrote it?
I am not sure why my 'reverse_evens" function is not passing. I tested it and it seems to work just find in IDLE and with Workspaces. Thanks.
def first_4(alist):
return alist[:4]
def first_and_last_4(alist):
return first_4(alist) + alist[-4:]
def odds(alist):
return alist[1::2]
def reverse_evens(alist):
mylist = []
for i in range(len(aval),0,-1):
if i % 2 == 0:
mylist.append(aval[i])
return mylist
2 Answers
Aaron Nolan
5,714 PointsYou're very close to the correct answer just remember that when you get the length of a list, for example:
alist = [1, 2, 3, 4, 5]
len() will return 5 but the last index is actually 4.
So it actually needs to be written like so:
def reverse_evens(alist):
mylist = []
for i in range(len(alist),-1,-1): # You should start at -1, not 0 as that index would be out of bounds
if (i - 1) % 2 == 0: # -1 so you're checking the correct index
mylist.append(alist[i - 1]) # -1 so you are appending the correct index
return mylist
This can also be solved by using slicing also, by checking the size of the list first:
def reverse_evens(alist):
if len(alist) % 2 == 0:
return alist[len(alist) - 2::-2]
else:
return alist[::-2]
Hope this helps and happy coding :)
JeanMartin Ghecea
5,770 PointsThank you Aaron. Yes, that did it! :)