I'm not sure why I get 0 from [9], I guess there's something wrong in my code using instance variable, can anyone help explain to me about the errors in my code? Thanks

'''

class Solution(object):

```
def sumNumbers(self, root):
if not root:
return 0
self.results=0
self.pathSum(root,0,self.results)
return self.results
def pathSum(self,root,result,results):
if root:
self.pathSum(root.left,result*10+root.val,results)
self.pathSum(root.right,result*10+root.val,results)
if not root.left and not root.right:
results+=result*10+root.val
```

'''