Unable to reverse list in Python

Question

I have tried several methods, and for some reason I cannot reverse this list. Here is my code:

array = []
elements = str(input().split())
array.append(elements)
array.reverse()
print(array)

This simply returns the original list. array[::-1] does the same thing. The reversed function outputs <list_reverseiterator object at 0x05AC1550>. How can I do this?

Asked By: Adam Grey

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Source

Answer 1

You are taking input then splitting it and then again converting it to string.
If you want to split your inputs into a List and then reverse it then you should try this:

array = []
elements = input().split()
print(elements)
elements.reverse()
print(elements)

Answered By: Bishakh Ghosh

Answer 2

See @Bishakh Ghosh answer first. As to why your code is not working:

elements is an array (list). You are appending it to array making it look like:

array = [[element1, element2, etc ]]

which is an array(list) of an array(list). You actually need to do this:

array += elements

Now array will have this:

array = [element1, element2, etc]

This will work as you expect. The shorter (than your code) way will be:

print(input().split()[::-1])

Answered By: mshsayem

Answer 3

In your code arrayis instantiated as an empty list. Additionally, elements = str(input().split()) will create a list of items, however you need to specify the delimiter in your split method ie split("") or split(" "). As a result, you are appending a list of stuff (possibly an empty list) to an empty list. Like Bishakh said don’t convert an array into a string version of itself, which is why you are getting a memory location (since your compiler is treating the array as a string object and not an array).

Try something like

elements = input().split(" ")
elements.reverse() or elements = elements[::-1]

Answered By: Nathan Patnam

Answer 4

Assign the result:

array = array[::-1]

Answered By: fyngyrz

Unable to reverse list in Python

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