How do I traverse a binary tree in Python?

How do I traverse a binary tree in Python?

You can traverse a binary tree using different methods like in-order, pre-order, and post-order traversal. Which one would you like to learn about?

Can you explain in-order traversal?

Sure! In-order traversal visits the left subtree, the root node, and then the right subtree. Here's a simple implementation in Python:

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

    def in_order_traversal(self):
        if self.left:
            self.left.in_order_traversal()
        print(self.val)
        if self.right:
            self.right.in_order_traversal()

What about pre-order traversal?

Pre-order traversal visits the root node first, then the left subtree, and finally the right subtree. Here's how you can implement it:

def pre_order_traversal(node):
    if node:
        print(node.val)
        pre_order_traversal(node.left)
        pre_order_traversal(node.right)

Thanks! Can you show me post-order traversal too?

Of course! Post-order traversal visits the left subtree, then the right subtree, and finally the root node. Here's the implementation:

def post_order_traversal(node):
    if node:
        post_order_traversal(node.left)
        post_order_traversal(node.right)
        print(node.val)