Thousand Separator

Given an integer n, add a dot (".") as the thousands separator and return it in string format.

Example 1:

Input: n = 987
Output: "987"

Example 2:

Input: n = 1234
Output: "1.234"

Constraints:

• 0 <= n <= 231 - 1

SOLUTION:

class Solution:
    def thousandSeparator(self, n: int) -> str:
        n = str(n)
        l = len(n)
        for i in range(1, l):
            if i % 3 == 0:
               n = n[ : l - i] + '.' + n[l - i : ]
        return n