python中的树不打印子元素

class TreeNode:
    def __init__(self, value):
        self.value = value
        self.children = []

def print_tree(node):
    print(node.value)  # 打印节点的值
    for child in node.children:
        print_tree(child)  # 递归打印子节点

# 创建一个树的示例
root = TreeNode(1)
node2 = TreeNode(2)
node3 = TreeNode(3)
node4 = TreeNode(4)
node5 = TreeNode(5)

root.children = [node2, node3]
node2.children = [node4, node5]

# 打印树的结构，但不打印子元素
print_tree(root)