Deprecate WAVDataset, and pylint fix

Signed-off-by: Yong Tang <[email protected]>

Author: yongtang

tensorflow_io/audio/python/ops/audio_ops.py

@@ -17,9 +17,18 @@
 from __future__ import division
 from __future__ import print_function
 
+import warnings
+
 import tensorflow as tf
 from tensorflow_io.core.python.ops import data_ops
 
+warnings.warn(
+    "The tensorflow_io.audio.WAVDataset is "
+    "deprecated. Please look for tfio.IOTensor.from_audio "
+    "for reading WAV files into tensorflow.",
+    DeprecationWarning)
+
+
 class AudioDataset(data_ops.Dataset):
   """A Audio File Dataset that reads the audio file."""
 

tensorflow_io/core/python/ops/io_tensor.py

@@ -260,7 +260,7 @@ def from_kafka(cls,
     """
     with tf.name_scope(kwargs.get("name", "IOFromKafka")):
       return kafka_io_tensor_ops.KafkaIOTensor(
-        subscription,
-        servers=kwargs.get("servers", None),
-        configuration=kwargs.get("configuration", None),
-        internal=True)
+          subscription,
+          servers=kwargs.get("servers", None),
+          configuration=kwargs.get("configuration", None),
+          internal=True)