Update CART.ipynb

Author: luwill

charpter7_decision_tree/CART.ipynb

@@ -244,7 +244,7 @@
     "from sklearn import datasets\n",
     "data = datasets.load_iris()\n",
     "X, y = data.data, data.target\n",
-    "X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3)\n",
+    "X_train, X_test, y_train, y_test = train_test_split(X, y.reshape(-1,1), test_size=0.3)\n",
     "clf = ClassificationTree()\n",
     "clf.fit(X_train, y_train)\n",
     "y_pred = clf.predict(X_test)\n",