Best practise for creating BST : python

So I am implementing a Binary Search Tree but am confused as to whether I should have a Node class as well as a Bst class or just one class.

The reason why is because I know a BST is made up of nodes but at any point you can take a node and all the nodes beneath it and that essentially is a BST too.

If I have the following code where its one thing then I when inserting I can call my code like so self.left.insert(data)

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

def insert(self, data):
    node_to_insert = Bst(data)
    if data < self.data:
        if self.left is None:
            self.left = Bst(data)
        else:
            self.left.insert(data)
    else:
        if self.right is None:
            self.right = Bst(data)
        else:
            self.right.insert(data)

If I do it the other way where they are two seperate things a Node and a BST then in my insert method I have self.insert(data, node.left):

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

class Bst():
    def __init__(self, root=None):
        self.root = root

    def insert(self, data, node):
        node_to_insert = Node(data)

        if node is None:
            node = node_to_insert
        else:
            if data < node.data:
                if node.left is None:
                    node.left = node_to_insert
                else:
                    self.insert(data, node.left)
            else:
                if node.right is None:
                    node.right = node_to_insert
                else:
                    self.insert(data, node.right)

So my question is which is better code self.insert(data, node.left) or self.left.insert(data).

I would assume self.left.insert(data) as when the user is inserting they just have to write bst.insert(5) where as with the other one they say bst.insert(bst.root, 5)