How do I implement a binary search tree in Python?

How do I implement a binary search tree in Python?

To implement a binary search tree (BST) in Python, you can start by defining a class for the tree nodes.

What should the node class look like?

The node class should have attributes for the value, left child, and right child. Here's a simple example:

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

How do I insert a new value into the BST?

You can create an insert method that compares the new value with the current node's value and decides whether to go left or right. Here's a basic implementation:

class BinarySearchTree:
    def __init__(self):
        self.root = None

    def insert(self, value):
        if not self.root:
            self.root = Node(value)
        else:
            self._insert_recursively(self.root, value)

    def _insert_recursively(self, node, value):
        if value < node.value:
            if node.left:
                self._insert_recursively(node.left, value)
            else:
                node.left = Node(value)
        else:
            if node.right:
                self._insert_recursively(node.right, value)
            else:
                node.right = Node(value)

Can you show me how to traverse the tree?

Sure! You can implement in-order, pre-order, and post-order traversals. Here's an example of in-order traversal:

def in_order_traversal(node):
    if node:
        in_order_traversal(node.left)
        print(node.value)
        in_order_traversal(node.right)