class BSTree: """ The binary search tree """ def __init__(self, val): """ Initializae the BSTree """ # Your code here pass def search(self, val): """ Search for a value in the tree, and return the tree node @return: the tree node that contain the val None if val is not in the tree """ # Your code here pass def insert(self, val): """ Insert a value """ # Your code here pass def delete(self, val): """ Delete a value from the tree """ # Your code here pass def toList(self, val): """ Convert tree values into a list in in-order traversal """ # Your code here pass

以下是一个二叉搜索树（Binary Search Tree）的 Python 实现，包括了插入、删除、搜索和转换为列表等方法。

class TreeNode:
    """The tree node class"""
    def __init__(self, val):
        self.val = val
        self.left = None
        self.right = None

class BSTree:
    """The binary search tree"""

    def __init__(self, val):
        """Initialize the BSTree"""
        self.root = TreeNode(val)

    def search(self, val):
        """Search for a value in the tree, and return the tree node
        @return: the tree node that contain the val
        None if val is not in the tree
        """
        curr_node = self.root
        while curr_node:
            if curr_node.val == val:
                return curr_node
            elif curr_node.val > val:
                curr_node = curr_node.left
            else:
                curr_node = curr_node.right
        return None

    def insert(self, val):
        """Insert a value"""
        new_node = TreeNode(val)
        if not self.root:
            self.root = new_node
            return
        curr_node = self.root
        while curr_node:
            if curr_node.val > val:
                if curr_node.left:
                    curr_node = curr_node.left
                else:
                    curr_node.left = new_node
                    return
            else:
                if curr_node.right:
                    curr_node = curr_node.right
                else:
                    curr_node.right = new_node
                    return

    def delete(self, val):
        """Delete a value from the tree"""
        def find_min_node(node):
            while node.left:
                node = node.left
            return node

        def delete_node(node, val):
            if not node:
                return None
            if node.val == val:
                if not node.left and not node.right:
                    return None
                if not node.left:
                    return node.right
                if not node.right:
                    return node.left
                min_node = find_min_node(node.right)
                node.val = min_node.val
                node.right = delete_node(node.right, min_node.val)
            elif node.val > val:
                node.left = delete_node(node.left, val)
            else:
                node.right = delete_node(node.right, val)
            return node

        self.root = delete_node(self.root, val)

    def toList(self):
        """Convert tree values into a list in in-order traversal"""
        res = []
        def inorder_traversal(node):
            if not node:
                return
            inorder_traversal(node.left)
            res.append(node.val)
            inorder_traversal(node.right)
        inorder_traversal(self.root)
        return res

使用方法：

bst = BSTree(5)
bst.insert(3)
bst.insert(7)
bst.insert(2)
bst.insert(4)
bst.insert(6)
bst.insert(8)

print(bst.toList())  # [2, 3, 4, 5, 6, 7, 8]

bst.delete(5)

print(bst.toList())  # [2, 3, 4, 6, 7, 8]

node = bst.search(7)
print(node.val)  # 7