# Learn Tree Traversal by Building a Binary Search Tree - Step 32

### Tell us what’s happening:

The problem I’m having is with the assignment of the call to the _delete method. The challenge says “Assign the function call to the left node.” But I’m not sure what “left node” it’s talking about. I’ve tried:

``````left = _delete(node.left, key)
node.left = _delete(node.left, key)
self.left = _delete(node.left, key)
``````

None of them work. Is there maybe something else that I’m missing?

``````class TreeNode:
def __init__(self, key):
self.key = key
self.left = None
self.right = None

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

def insert(self,key):
self.root = self._insert(self.root, key)

def _insert(self, node, key):
if node is None:
return TreeNode(key)
if key < node.key:
node.left = self._insert(node.left, key)
elif key > node.key:
node.right = self._insert(node.right, key)
return node

def search(self, key):
return self._search(self.root, key)

def _search(self, node, key):
if node is None or node.key == key:
return node
if key < node.key:
return self._search(node.left, key)
return self._search(node.right, key)

def delete(self, key):
self.root = self._delete(self.root, key)

# User Editable Region

def _delete(self, node, key):
if node is None:
return node
if key < node.key:
_delete(node.left, key)

# User Editable Region

``````

User Agent is: `Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 Edg/120.0.0.0`
`_delete` is a method of the class so you need to use `self._delete` to access it