Return reversed list in python

Question

In python2.7, I tried to return a reversed list directly using the below code but it didnt return anything.

Code 1:

def reverse3(nums):
    return nums.reverse()

The below code works and I am confused by the difference between Code 1 and Code 2. Please explain what's happening here.

Code 2:

def reverse3(nums):
    nums.reverse()
    return nums

`list.reverse` does not return, it just reverses items. `return nums[::-1]`, — falsetru, Jul 29 '15 at 05:33

score 2 · Answer 1 · answered Jul 29 '15 at 05:33

2

obviously, nums.reverse() does not return any value.. it just reverses the list..

answered Jul 29 '15 at 05:33

mlwn

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The6thSense · Accepted Answer · 2015-07-29T05:40:57.600

In the first thing you are passing the return type of reverse function which is None. This is due to the fact reverse() acts on the list changes the list and returns None

a=[1,2,3]

print a.reverse()
None

a
[3, 2, 1]

Where as if you did as falsetru saying you are returning a list which is the reversed order of the list and it does not change the actual list

i.e)

a=[1,2,3]

a[::-1]
[3, 2, 1]
print a
[1,2,3]

Return reversed list in python

2 Answers2