Reverse Function changes original list as well

Asked Nov 19 '20 at 13:36

Active Nov 19 '20 at 13:45

Viewed 43 times

I have the function written which should work good theoretically but the function seems to be changing the original list as well where i don't want the original to reversed but instead show the variable a in reverse only

def listreverse(list_input):
    length = 0
    list_swapped1 = list_input
    for i in range(len(list_input)):
        length += 1
    swap = (length + 1) // 2
    for i in range(swap):
        temp1 = list_swapped1[0 + i]
        temp2 = list_swapped1[(length - 1) - i]
        list_swapped1[0 + i] = temp2
        list_swapped1[(length - 1) - i] = temp1
    return list_swapped1


mylist = [1, 2, 8, 4, 5]
a = listreverse(mylist)
print(a)
print(mylist)

OUTPUT

[5, 4, 8, 2, 1]
[5, 4, 8, 2, 1]

thanks in advance

edited Nov 19 '20 at 13:38

asked Nov 19 '20 at 13:36

Muhammad Naseem Siddiqui

1

try `list_swapped1 = list_input.copy()` – Jean-François Fabre Nov 19 '20 at 13:37
or `a = mylist[::-1]` if you just want to reverse the list – Jean-François Fabre Nov 19 '20 at 13:38
@Jean-FrançoisFabre `a = mylist[::-1]` works now. Thank you but is this a core python built-in function because in the assignment i am told not to use such methods. – Muhammad Naseem Siddiqui Nov 19 '20 at 13:43
first reflex in python: there's a builtin method to do simple things, almost everytime. Avoid custom solutions unless it's a very specific requirement – Jean-François Fabre Nov 19 '20 at 13:44

Reverse Function changes original list as well

0 Answers0