Input a number with any number of digits and output it in reverse order of digits.

[zivoni]

Little necronitpicking:

sort with reverse keyword gives a list ordered in a reverse order, not a reversed list. For the number/list used as an example it does not matter, as it was ordered, but otherwise it could. Beside [::-1] it could be done with .reverse() or reversed().

As "reversing" list is equivalent to sorting it on index in decreasing order, I tried to abuse sort/sorted to get such result and ended with:

In [38]: a = [1, 2, 5, 3]

In [39]: sorted(a, key = lambda x, i=iter(range(len(a))) : -next(i))
Out[39]: [3, 5, 2, 1]

it looks ugly, but probably less ugly than:

In [41]: list(map(lambda x:x[1], sorted(enumerate(a), reverse=True)))
Out[41]: [3, 5, 2, 1]

Perhaps there are other ways how to reverse list with sort/sorted one-liner and built-ins ...