change: add csv deserializer (#737)

Author: laurenyu

src/sagemaker/predictor.py

@@ -229,6 +229,21 @@ def _row_to_csv(obj):
     return ','.join(obj)
 
 
+class _CsvDeserializer(object):
+    def __init__(self, encoding='utf-8'):
+        self.accept = CONTENT_TYPE_CSV
+        self.encoding = encoding
+
+    def __call__(self, stream, content_type):
+        try:
+            return list(csv.reader(stream.read().decode(self.encoding).splitlines()))
+        finally:
+            stream.close()
+
+
+csv_deserializer = _CsvDeserializer()
+
+
 class BytesDeserializer(object):
     """Return the response as an undecoded array of bytes.
 

tests/unit/test_predictor.py

@@ -21,8 +21,9 @@
 import numpy as np
 
 from sagemaker.predictor import RealTimePredictor
-from sagemaker.predictor import json_serializer, json_deserializer, csv_serializer, BytesDeserializer, \
-    StringDeserializer, StreamDeserializer, numpy_deserializer, npy_serializer, _NumpyDeserializer
+from sagemaker.predictor import json_serializer, json_deserializer, csv_serializer, \
+    csv_deserializer, BytesDeserializer, StringDeserializer, StreamDeserializer, \
+    numpy_deserializer, npy_serializer, _NumpyDeserializer
 from tests.unit import DATA_DIR
 
 # testing serialization functions
@@ -141,6 +142,21 @@ def test_csv_serializer_csv_reader():
         assert result == validation_data
 
 
+def test_csv_deserializer_single_element():
+    result = csv_deserializer(io.BytesIO(b'1'), 'text/csv')
+    assert result == [['1']]
+
+
+def test_csv_deserializer_array():
+    result = csv_deserializer(io.BytesIO(b'1,2,3'), 'text/csv')
+    assert result == [['1', '2', '3']]
+
+
+def test_csv_deserializer_2dimensional():
+    result = csv_deserializer(io.BytesIO(b'1,2,3\n3,4,5'), 'text/csv')
+    assert result == [['1', '2', '3'], ['3', '4', '5']]
+
+
 def test_json_deserializer_array():
     result = json_deserializer(io.BytesIO(b'[1, 2, 3]'), 'application/json')