Python Forum

So I am trying to create a binary tree within python using classes but I have gotten stuck on this last bit.

def deleteNode(self, node, data):
        if self.searchNode(node, data) is None:
            print("Node doesn't exist")
            return None
        else:
            # Node exists
            if data < node.data:
                node.left = self.deleteNode(node.left, data)
            elif data > node.data:
                node.right = self.deleteNode(node.right, data)
            elif data == node.data:
                # Node has no children
                if node.left is None and node.right is None:
                    del node
                    return None
                # Node has 1 child
                elif node.left is None:
                    temp = node.right
                    node = None
                    return temp
                elif node.right is None:
                    temp = node.left
                    node = None
                    return temp
                else:
                    # Node has 2 children so find inorder successor
                    temp = self.inorderSuccessor(node.right)
                    node.data = temp.data

This code is meant to remove an element and replace it within it's child. Which is does perfectly fine up until the node has 2 children.
When this happens, it is meant to find the in-order successor, replace the targeted node with it's contents and then either delete the node if it doesn't have any children or replace the node with it's children if they exist.
It can do the no children deletion but it seems to struggle on the other one.

For example, in the following binary tree, if I wanted to delete node '50', then it is meant to to be replaced by '54' and '56' should replace node '54':



However, this does not work.

Here's the rest of my code:

import random

randomList = []
randomListSize = 10
resultList = []

class Node:
    def __init__(self, value):
        self.data = value
        self.left = None
        self.right = None

class Tree:
    def createNode(self, data):
        return Node(data)

    def insertNode(self, node, data):
        if node is None:
            # Create root node
            return self.createNode(data)
        # Root node already exists
        if data < node.data:
            # New node data is less than root node
            node.left = self.insertNode(node.left, data)
        elif data > node.data:
            # New node data is bigger than root node
            node.right = self.insertNode(node.right, data)
        # Save new node data
        return node

    def searchNode(self, node, data):
        if node is None or node.data == data:
            # Node is found
            return node
        elif node.data > data:
            # Node may be to the left of the root
            return self.searchNode(node.left, data)
        elif node.data < data:
            # Node may be to the right of the root
            return self.searchNode(node.right, data)
        else:
            # Node is not found
            return None

    def deleteNode(self, node, data):
        if self.searchNode(node, data) is None:
            print("Node doesn't exist")
            return None
        else:
            # Node exists
            if data < node.data:
                node.left = self.deleteNode(node.left, data)
            elif data > node.data:
                node.right = self.deleteNode(node.right, data)
            elif data == node.data:
                # Node has no children
                if node.left is None and node.right is None:
                    del node
                    return None
                # Node has 1 child
                elif node.left is None:
                    temp = node.right
                    node = None
                    return temp
                elif node.right is None:
                    temp = node.left
                    node = None
                    return temp
                else:
                    # Node has 2 children so find inorder successor
                    temp = self.inorderSuccessor(node.right)
                    node.data = temp.data

    def inorderSuccessor(self, node):
        while node.left is not None:
            node = node.left
        return node

    def preorder(self, node):
        # Root then left sub-tree then right sub-tree
        if node is not None:
            print(node.data)
            self.preorder(node.left)
            self.preorder(node.right)

    def inorder(self, node):
        # Left sub-tree then root then right sub-tree
        if node is not None:
            self.inorder(node.left)
            print(node.data)
            self.inorder(node.right)

    def postorder(self, node):
        # Left sub-tree then right sub-tree then root
        if node is not None:
            self.postorder(node.left)
            self.postorder(node.right)
            print(node.data)

def setup():
    randomList = []
    for i in range(randomListSize):
        randomList.append(random.randint(1, 100))
    print(randomList)
    randomList = [59, 90, 93, 23, 60, 85, 64, 23, 15, 15]
    print(randomList)
    tree = Tree()
    root = tree.insertNode(None, randomList[0])  # Create root node
    for i in range(len(randomList) - 1):
        tree.insertNode(root, randomList[i + 1])  # Create each child node
    return tree, root

def traverse():
    while True:
        try:
            user = int(input("1 for preorder, 2 for inorder and 3 for postorder: "))
            if user == 1:
                tree.preorder(root)
            elif user == 2:
                tree.inorder(root)
            elif user == 3:
                tree.postorder(root)
            else:
                print("Invalid choice")
        except ValueError:
            print("Invalid choice")
        break

if __name__ == "__main__":
    tree, root = setup()
    while True:
        try:
            userChoice = int(
                input("Enter 1 to add a node, 2 to search for a node, 3 to delete a node and 4 to traverse the tree: "))
            if userChoice == 1:
                newNode = int(input("Enter a number: "))
                tree.insertNode(root, newNode)
            elif userChoice == 2:
                userSearch = int(input("Enter a number: "))
                if tree.searchNode(root, userSearch) is not None:
                    print(userSearch, "exists")
                else:
                    print("Node doesn't exist")
            elif userChoice == 3:
                removeNode = int(input("Enter a number: "))
                tree.deleteNode(root, removeNode)
            elif userChoice == 4:
                traverse()
            else:
                print("Invalid choice")
        except ValueError:
            print("Invalid choice")

If anyone has any ideas on how to fix this, it'll be greatly appreciated. If anyone has any ideas on how to improve my code, that'll be appreciated too.

Thanks!