CODEWITHSUNDEEP
python
Eli B
Eli B

Reputation: 51

Python Data structures binary search tree

I can't figure out the type of error that I'm getting.

Traceback (most recent call last): File "C:/Users/Eli/.PyCharmCE2019.2/config/scratches/BinarySearchTree.py", line 43, in bt.printTreePreOrder(bt.Root()) TypeError: 'NoneType' object is not callable

class BinaryTreeNode:


 def __init__(self,key, data = None):
        self.key = key
        self.value = data
        self.left = None
        self.right = None
class BinarySearchTree:
    def __init__(self):
        self.Root = None
        self.size = 0
    def __len__(self):
        return self.size
    def root (self):
        return self.Root
    def insert(self,key,data):
        new_node = BinaryTreeNode(key,data)
        x = self.Root
        y = None
        while x != None:
            y = x
            if key < y.key:
                x = x.left
            else:
                x = x.right
                if y == None:
                    self. key < y.key
                    y.left = new_node
                else:
                    y.right = new_node
            self.size +=1
    def printTreePreOrder(self,node):
        print(node.key)
        if node.left:
            self.printTreePreOrder(node.left)
        if node.right:
            self.printTreePreOrder(node.right)
if __name__ == "__main__":
    bt = BinarySearchTree()
    bt.insert(12,'bill')
    bt.insert(6,'Tom')
    bt.insert(14,'jill')
    bt.insert(3,'guy')
    bt.printTreePreOrder(bt.Root())

Upvotes: 0

Views: 136

Answers (1)

c_sagan
c_sagan

Reputation: 512

You're attempting to call Root as if it were a function, but it's only a member variable of class BinaryTreeNode, therefore is not callable.

Furthermore, it is returning as NoneType because you initialize it to None and it is never assigned to any other value.

The way you have it implemented, you should do bt.printTreePreOrder(bt.Root)

Upvotes: 2

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