BST.py

class Node:
    """
    Tree node: left and right child + data which can be any object
    """
    def __init__(self, data=None):
        """
        Node constructor
        @param data node data object
        """
        self.left = None
        self.right = None
        self.data = data

    def insert(self, data):
        """
        Insert new node with data

        @param data: Node data object to insert
        """
        if self.data:
            if data < self.data:
                if self.left is None:
                    self.left = Node(data)
                else:
                    self.left.insert(data)
            else:
                if self.right is None:
                    self.right = Node(data)
                else:
                    self.right.insert(data)
        else:
            self.data = data