Load the dataset into memory. If data is not divided into train/test, use test_percent to divide the data

def load_data(self, test_percent=0.15):
        """Load the dataset into memory. If data is not divided into train/test, use test_percent to divide the data"""
        train_images = list()
        train_labels = list()
        test_images = list()
        test_labels = list()
        return train_images, train_labels, test_images, test_labels