MNIST.py 文件源码

def _maybe_download_and_extract(self):
        """Download and extract the MNIST dataset"""
        data_sets = mnist.read_data_sets(
            self._data_dir,
            dtype=tf.uint8,
            reshape=False,
            validation_size=self._num_examples_per_epoch_for_eval)

        # Convert to Examples and write the result to TFRecords.
        if not tf.gfile.Exists(os.path.join(self._data_dir, 'train.tfrecords')):
            convert_to_tfrecords(data_sets.train, 'train', self._data_dir)

        if not tf.gfile.Exists(
                os.path.join(self._data_dir, 'validation.tfrecords')):
            convert_to_tfrecords(data_sets.validation, 'validation',
                                 self._data_dir)

        if not tf.gfile.Exists(os.path.join(self._data_dir, 'test.tfrecords')):
            convert_to_tfrecords(data_sets.test, 'test', self._data_dir)