1. from sklearn.model_selection import train_test_split
    2. from sklearn.neighbors import KNeighborsClassifier
    3. from sklearn.metrics import accuracy_score
    6. X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=666)
    8. knn_clf = KNeighborsClassifier(n_neighbors=3)
    9. knn_clf.fit(X_train, y_train)
    10. y_predict = knn_clf.predict(X_test)
    11. accuracy_score(y_test, y_predict)  # 0.98888888888888893