[punch in] flip the string (simple)

describe
Write a method , Accepts the given string as input , Returns a new string after flipping this string character by character .
Examples 1：

 Input ："hello"
 Output ："olleh"

Examples 2：

 Input ："hello world"
 Output ："dlrow olleh"

class Solution:
    """ @param s: a string @return: return a string """
    def reverseString(self, s):
        # write your code here
        l = len(s)
        ans = ''
        for i in range(l-1,-1,-1):
            ans += s[i]
        return ans