一、獲取二叉樹的深度

就是二叉樹最后的層次，如下圖：

實現代碼：
代碼如下:
def getheight(self):
        ''' 獲取二叉樹深度 '''
        return self.__get_tree_height(self.root)

    def __get_tree_height(self, root):
        if root is 0:
            return 0
        if root.left is 0 and root.right is 0:
            return 1
        else:
            left = self.__get_tree_height(root.left)
            right = self.__get_tree_height(root.right)
            if left < right:
                return right + 1
            else:
                return left + 1

二、葉子的統計

葉子就是二叉樹的節點的 left 指針和 right 指針分別指向空的節點
代碼如下:
def getleafcount(self):
        ''' 獲取二叉樹葉子數 '''
        return self.__count_leaf_node(self.root)

    def __count_leaf_node(self, root):
        res = 0
        if root is 0:
            return res
        if root.left is 0 and root.right is 0:
            res += 1
            return res
        if root.left is not 0:
            res += self.__count_leaf_node(root.left)
        if root.right is not 0:
            res += self.__count_leaf_node(root.right)
        return res

三、統計葉子的分支節點

與葉子節點相對的其他節點 left 和 right 的指針指向其他節點

代碼如下:
def getbranchcount(self):
        ''' 獲取二叉樹分支節點數 '''