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    "# Binary Search Tree\n",
    "**Constructor** sets three attributes: data, left subtree and right subtree.  \n",
    "**Insert** inserts a new subtree into the proper location.  \n",
    "**Find** finds a value. If value not found, returns False.  \n",
    "**Get_size** returns the number of nodes in the tree (excluding None nodes).  \n",
    "**Preorder** prints a preorder traversal of the tree.  \n",
    "**Inorder** prints an inorder traversal of the tree."
   ]
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    "class Tree:\n",
    "    def __init__(self, data, left=None, right=None):\n",
    "        self.data = data\n",
    "        self.left = left\n",
    "        self.right = right\n",
    "    def insert(self, data):\n",
    "        if self.data == data:\n",
    "            return False # duplicate value\n",
    "        elif self.data > data:\n",
    "            if self.left is not None:\n",
    "                return self.left.insert(data)\n",
    "            else:\n",
    "                self.left = Tree(data)\n",
    "                return True\n",
    "        else:\n",
    "            if self.right is not None:\n",
    "                return self.right.insert(data)\n",
    "            else:\n",
    "                self.right = Tree(data)\n",
    "                return True\n",
    "    def find(self, data):\n",
    "        if self.data == data:\n",
    "            return data\n",
    "        elif self.data > data:\n",
    "            if self.left is None:\n",
    "                return False\n",
    "            else:\n",
    "                return self.left.find(data)\n",
    "        elif self.data < data:\n",
    "            if self.right is None:\n",
    "                return False\n",
    "            else:\n",
    "                return self.right.find(data)\n",
    "    def get_size(self):\n",
    "        if self.left is not None and self.right is not None:\n",
    "            return 1 + self.left.get_size() + self.right.get_size()\n",
    "        elif self.left:\n",
    "            return 1 + self.left.get_size()\n",
    "        elif self.right:\n",
    "            return 1 + self.right.get_size()\n",
    "        else:\n",
    "            return 1\n",
    "    def preorder(self):\n",
    "        if self is not None:\n",
    "            print (self.data, end=' ')\n",
    "            if self.left is not None:\n",
    "                self.left.preorder()\n",
    "            if self.right:\n",
    "                self.right.preorder()\n",
    "    def inorder(self):\n",
    "        if self is not None:\n",
    "            if self.left is not None:\n",
    "                self.left.inorder()\n",
    "            print (self.data, end=' ')\n",
    "            if self.right is not None:\n",
    "                self.right.inorder()\n"
   ]
  },
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Test Code\n",
    "We create a new tree, insert one value, insert a whole list of values, find all values from 1 to 15 (False for 0, 5 and 8 shows that those values are not in the tree), print the size of the tree, print preorder and postorder traversals."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 70,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "False 1 2 3 4 False 6 7 False 9 10 11 12 13 14 15 \n",
      " 13\n",
      "7 2 1 3 6 4 9 15 10 12 11 13 14 \n",
      "1 2 3 4 6 7 9 10 11 12 13 14 15 \n"
     ]
    }
   ],
   "source": [
    "tree = Tree(7)\n",
    "tree.insert(9)\n",
    "for i in [15, 10, 2, 12, 3, 1, 13, 6, 11, 4, 14, 9]:\n",
    "    tree.insert(i)\n",
    "for i in range(16):\n",
    "    print(tree.find(i), end=' ')\n",
    "print('\\n', tree.get_size())\n",
    "\n",
    "tree.preorder()\n",
    "print()\n",
    "tree.inorder()\n",
    "print()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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