new_contents: class Solution:
      # @param {int} n an integer
      # @return {boolean} true if this is a happy number or false
      def isHappy(self, n):
          # Write your code here
          sum = n
          nums = {}
          while sum != 1:
              sum = self.cal_square_sum(sum)
              if sum in nums:
                  return False
              nums[sum] = 1
          return True
              
      def cal_square_sum(self, n):
          sum = 0
          while n > 0:
              sum += (n % 10) ** 2
              n = n / 10
          return sum
  
subject: Create happy-number.py