Update CART.ipynb

Author: luwill

charpter7_decision_tree/CART.ipynb

@@ -291,7 +291,8 @@
    "source": [
     "from sklearn.datasets import load_boston\n",
     "X, y = load_boston(return_X_y=True)\n",
-    "X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3)\n",
+    "# 此处注意numpy版本造成的报错y.reshape(-1,1)\n"
+    "X_train, X_test, y_train, y_test = train_test_split(X, y.reshape(-1,1), test_size=0.3)\n",
     "model = RegressionTree()\n",
     "model.fit(X_train, y_train)\n",
     "y_pred = model.predict(X_test)\n",