new_contents: # Definition for a binary tree node.
  # class TreeNode(object):
  #     def __init__(self, x):
  #         self.val = x
  #         self.left = None
  #         self.right = None
  
  class Solution(object):
      def sortedArrayToBST(self, nums):
          """
          :type nums: List[int]
          :rtype: TreeNode
          """
          if nums == []:
              return None
          m = (len(nums) - 1) / 2
          root = TreeNode(nums[m])
          root.left = self.sortedArrayToBST(nums[:m])
          root.right = self.sortedArrayToBST(nums[m + 1:])
          return root
  
subject: Create ConvSortedArr2BST_001_rec.py