二叉树中存在Q.Is节点？[python]如何在给定代码中返回True或false

class TreeNode:
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right

def is_node_present(root, target):
    if root is None:
        return False
    if root.val == target:
        return True
    return is_node_present(root.left, target) or is_node_present(root.right, target)

# 示例二叉树
#       1
#      / \
#     2   3
#    / \   \
#   4   5   6
#        \
#         7
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)
root.left.right = TreeNode(5)
root.right.right = TreeNode(6)
root.left.right.right = TreeNode(7)

target_node = "Q.Is"  # 目标节点值

result = is_node_present(root, target_node)
print(result)  # 输出：False