Sum of Nodes with Even-Valued Grandparent (Leetcode 1315)

Problem Link: https://leetcode.com/problems/sum-of-nodes-with-even-valued-grandparent/

class Solution:

    def sumEvenGrandparent(self, root: TreeNode) -> int:
    
        if(root is None):
            return 0
            
        lans=self.sumEvenGrandparent(root.left)
        rans=self.sumEvenGrandparent(root.right)
        ans=0
        
        if(root.val%2==0):
            if(root.left is not None):
                if(root.left.left is not None):
                    ans+=root.left.left.val
                if(root.left.right is not None):
                    ans+=root.left.right.val
            if(root.right is not None):
                if(root.right.left is not None):
                    ans+=root.right.left.val
                if(root.right.right is not None):
                    ans+=root.right.right.val
                    t
        return lans+rans+ans