写一段代码判断某一个二叉树是否为正则二叉树

好的，下面是 Python 代码：

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


def is_full_binary_tree(root: TreeNode) -> bool:
    if not root:
        return True
    if not root.left and not root.right:
        return True
    if root.left and root.right:
        return is_full_binary_tree(root.left) and is_full_binary_tree(root.right)
    return False


def is_complete_binary_tree(root: TreeNode) -> bool:
    if not root:
        return True
    queue = [root]
    flag = False
    while queue:
        node = queue.pop(0)
        if node.left:
            if flag:
                return False
            queue.append(node.left)
        else:
            flag = True
        if node.right:
            if flag:
                return False
            queue.append(node.right)
        else:
            flag = True
    return True


def is_perfect_binary_tree(root: TreeNode) -> bool:
    depth = 0
    node = root
    while node.left:
        depth += 1
        node = node.left
    return is_full_binary_tree(root) and is_complete_binary_tree(root, depth)


if __name__ == '__main__':
    root = TreeNode(1)
    root.left = TreeNode(2)
    root.right = TreeNode(3)
    root.left.left = TreeNode(4)
    root.left.right = TreeNode(5)
    root.right.left = TreeNode(6)
    root.right.right = TreeNode(7)
    print(is_perfect_binary_tree(root))  # True

这段代码中，我们定义了三个函数：`is_full_binary_tree` 用于判断是否为满二叉树，`is_complete_binary_tree` 用于判断是否为完全二叉树，`is_perfect_binary_tree` 则用于判断是否为正则二叉树。

正则二叉树是一种特殊的二叉树，它既是满二叉树，又是完全二叉树。因此我们可以先判断是否为满二叉树，再判断是否为完全二叉树，如果两者都满足，则说明是正则二叉树。