Load dataset, use 20newsgroups dataset

def load_data():
    '''Load dataset, use 20newsgroups dataset'''
    digits = load_digits()
    X_train, X_test, y_train, y_test = train_test_split(digits.data, digits.target, random_state=99, test_size=0.25)

    ss = StandardScaler()
    X_train = ss.fit_transform(X_train)
    X_test = ss.transform(X_test)

    return X_train, X_test, y_train, y_test