Reverse String Leetcode Challenge June Day 4

We Just Swap elements of Left and Right Pointers and we increment left pointer ,decrement right pointer.
Python Code:
class Solution(object):
    def reverseString(self, s):
        l = 0
        r = len(s) - 1
        while l<r:
            s[l],s[r] = s[r],s[l]
            l+=1
            r-=1
Alternative Single Line Code:
def reverseString(s):
      s = s[::-1]