Python 3 Faster than 99.54% Simple Solution
````\nclass Solution:\n    def rangeSumBST(self, root: TreeNode, low: int, high: int) -> int:\n        if root:\n            if root.valhigh:\n                r
````\nclass Solution:\n    def rangeSumBST(self, root: TreeNode, low: int, high: int) -> int:\n        if root:\n            if root.val<low:\n                return self.rangeSumBST(root.right,low,high)\n            elif root.val>high:\n                return self.rangeSumBST(root.left,low,high)\n            return root.val + self.rangeSumBST(root.left,low,high) + self.rangeSumBST(root.right,low,high)\n        else:\n            return 0
['Recursion', 'Python', 'Python3']