Beats 98.7%, 8 line pythonic iterative solution
python\nclass Solution:        \n    def postorder(self, root: \'Node\') -> List[int]:  \n        ans = []\n        stack = [root]\n        while stack:\n      
```python\nclass Solution:        \n    def postorder(self, root: \'Node\') -> List[int]:  \n        ans = []\n        stack = [root]\n        while stack:\n            root = stack.pop()\n            if root: \n                ans.append(root.val)\n                stack += root.children\n        return ans[::-1]\n```
['Iterator', 'Python']