message: Improve documentation for TFRecordDataset.
  This adds a longer description and includes the example used for TFRecordWriter (https://www.tensorflow.org/api_docs/python/tf/io/TFRecordWriter)
diff: @@ -213,7 +213,48 @@ class TextLineDatasetV1(dataset_ops.DatasetV1Adapter):
  class _TFRecordDataset(dataset_ops.DatasetSource):
  - """A `Dataset` comprising records from one or more TFRecord files."""
  + """A `Dataset` comprising records from one or more TFRecord files.
  +
  + This dataset loads TFRecords from file as bytes, exactly as they were written.
  + `TFRecordDataset` does not do any parsing or decoding on its own. Parsing and
  + decoding can be done by applying `Dataset.map` transformations after the
  + `TFRecordDataset`.
  +
  + A minimal example is given below:
  +
  + >>> import tempfile
  + >>> example_path = os.path.join(tempfile.gettempdir(), "example.tfrecords")
  + >>> np.random.seed(0)
  +
  + >>> # Write the records to a file.
  + ... with tf.io.TFRecordWriter(example_path) as file_writer:
  + ... for _ in range(4):
  + ... x, y = np.random.random(), np.random.random()
  + ...
  + ... record_bytes = tf.train.Example(features=tf.train.Features(feature={
  + ... "x": tf.train.Feature(float_list=tf.train.FloatList(value=[x])),
  + ... "y": tf.train.Feature(float_list=tf.train.FloatList(value=[y])),
  + ... })).SerializeToString()
  + ... file_writer.write(record_bytes)
  +
  + >>> # Read the data back out.
  + >>> def decode_fn(record_bytes):
  + ... return tf.io.parse_single_example(
  + ... # Data
  + ... record_bytes,
  + ...
  + ... # Schema
  + ... {"x": tf.io.FixedLenFeature([], dtype=tf.float32),
  + ... "y": tf.io.FixedLenFeature([], dtype=tf.float32)}
  + ... )
  +
  + >>> for batch in tf.data.TFRecordDataset([example_path]).map(decode_fn):
  + ... print("x = {x:.4f}, y = {y:.4f}".format(**batch))
  + x = 0.5488, y = 0.7152
  + x = 0.6028, y = 0.5449
  + x = 0.4237, y = 0.6459
  + x = 0.4376, y = 0.8918
  + """
  def __init__(self, filenames, compression_type=None, buffer_size=None):
  """Creates a `TFRecordDataset`.
  