new_contents: class Solution:
      def transpose(self, A):
          """
          :type A: List[List[int]]
          :rtype: List[List[int]]
          """
          ret = [[0]*len(A) for i in range(len(A[0]))]
          for i in range(len(A)):
              for j in range(len(A[0])):
                  ret[j][i] = A[i][j]
          return ret
          
  
subject: Transpose Matrix