AVL树旋转的目的是为了保持树的平衡，但旋转操作的确会在树平衡的情况下发生。这是因为当插入或删除节点后，AVL树可能会产生不平衡的节点，即节点的左子树和右子树的高度差超过1。为了重新平衡树，需要进行旋转操作。下面是旋转操作的示例代码：

class AVLTree:

    def __init__(self):
        self.root = None

    def add(self, val):
        if not self.root:
            self.root = Node(val)
        else:
            self.root = self._add(val, self.root)

    def _add(self, val, node):
        if not node:
            return Node(val)
        elif node.val > val:
            node.left = self._add(val, node.left)
        else:
            node.right = self._add(val, node.right)

        node = self._balance(node)

        node.height = 1 + max(
            self._get_height(node.left),
            self._get_height(node.right))

        return node

    def _get_height(self, node):
        if not node:
            return 0
        else:
            return node.height

    def _get_balance(self, node):
        if not node:
            return 0
        else:
            return self._get_height(node.left) - self._get_height(node.right)

    def _balance(self, node):
        if self._get_balance(node) < -1:
            if self._get_balance(node.right) > 0:
                node.right = self._right_rotate(node.right)
            node = self._left_rotate(node)
        elif self._get_balance(node) > 1:
            if self._get_balance(node.left) < 0:
                node.left = self._left_rotate(node.left)
            node = self._right_rotate(node)

        return node

    def _left_rotate(self, node):
        r = node.right
        node.right = r.left
        r.left = node