[Leet Code] Thousand Separator

Leet Code: https://leetcode.com/problems/thousand-separator/

Problem:

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"

Example 3:

Input: n = 123456789
Output: "123.456.789"

Example 4:

Input: n = 0
Output: "0"

Constraints:

• 0 <= n < 2^31

Solution:

class Solution(object):
    def thousandSeparator(self, n):
        """
        :type n: int
        :rtype: str
        """
        stringN = str(n)
        if len(stringN) > 3:
            listOfN = list(stringN)
            listOfN.reverse()
            counter = 0
            for i in range(0,len(stringN),3):
                print i
                if i != 0:
                    listOfN.insert(i + counter,".")
                    counter += 1
            listOfN.reverse()
            return "".join(listOfN)
        else:
            return stringN