change: Support multiple Accept types

src/sagemaker/amazon/common.py

@@ -58,7 +58,7 @@ def serialize(self, data):
 class RecordDeserializer(BaseDeserializer):
     """Deserialize RecordIO Protobuf data from an inference endpoint."""
 
-    ACCEPT = "application/x-recordio-protobuf"
+    ACCEPT = ("application/x-recordio-protobuf",)
 
     def deserialize(self, data, content_type):
         """Deserialize RecordIO Protobuf data from an inference endpoint.

src/sagemaker/deserializers.py

@@ -52,13 +52,13 @@ def deserialize(self, stream, content_type):
     @property
     @abc.abstractmethod
     def ACCEPT(self):
-        """The content type that is expected from the inference endpoint."""
+        """The content types that are expected from the inference endpoint."""
 
 
 class StringDeserializer(BaseDeserializer):
     """Deserialize data from an inference endpoint into a decoded string."""
 
-    ACCEPT = "application/json"
+    ACCEPT = ("application/json",)
 
     def __init__(self, encoding="UTF-8"):
         """Initialize the string encoding.
@@ -87,7 +87,7 @@ def deserialize(self, stream, content_type):
 class BytesDeserializer(BaseDeserializer):
     """Deserialize a stream of bytes into a bytes object."""
 
-    ACCEPT = "*/*"
+    ACCEPT = ("*/*",)
 
     def deserialize(self, stream, content_type):
         """Read a stream of bytes returned from an inference endpoint.
@@ -108,7 +108,7 @@ def deserialize(self, stream, content_type):
 class CSVDeserializer(BaseDeserializer):
     """Deserialize a stream of bytes into a list of lists."""
 
-    ACCEPT = "text/csv"
+    ACCEPT = ("text/csv",)
 
     def __init__(self, encoding="utf-8"):
         """Initialize the string encoding.
@@ -143,7 +143,7 @@ class StreamDeserializer(BaseDeserializer):
     reading it.
     """
 
-    ACCEPT = "*/*"
+    ACCEPT = ("*/*",)
 
     def deserialize(self, stream, content_type):
         """Returns a stream of the response body and the MIME type of the data.
@@ -161,16 +161,17 @@ def deserialize(self, stream, content_type):
 class NumpyDeserializer(BaseDeserializer):
     """Deserialize a stream of data in the .npy format."""
 
-    ACCEPT = "application/x-npy"
-
-    def __init__(self, dtype=None, allow_pickle=True):
+    def __init__(self, dtype=None, accept="application/x-npy", allow_pickle=True):
         """Initialize the dtype and allow_pickle arguments.
 
         Args:
             dtype (str): The dtype of the data (default: None).
+            accept (str): The MIME type that is expected from the inference
+                endpoint (default: "application/x-npy").
             allow_pickle (bool): Allow loading pickled object arrays (default: True).
         """
         self.dtype = dtype
+        self.accept = accept
         self.allow_pickle = allow_pickle
 
     def deserialize(self, stream, content_type):
@@ -197,11 +198,21 @@ def deserialize(self, stream, content_type):
 
         raise ValueError("%s cannot read content type %s." % (__class__.__name__, content_type))
 
+    @property
+    def ACCEPT(self):
+        """The content types that are expected from the inference endpoint.
+
+        To maintain backwards compatability with legacy images, the
+        NumpyDeserializer supports sending only one content type in the Accept
+        header.
+        """
+        return (self.accept,)
+
 
 class JSONDeserializer(BaseDeserializer):
     """Deserialize JSON data from an inference endpoint into a Python object."""
 
-    ACCEPT = "application/json"
+    ACCEPT = ("application/json",)
 
     def deserialize(self, stream, content_type):
         """Deserialize JSON data from an inference endpoint into a Python object.
@@ -222,7 +233,7 @@ def deserialize(self, stream, content_type):
 class PandasDeserializer(BaseDeserializer):
     """Deserialize CSV or JSON data from an inference endpoint into a pandas dataframe."""
 
-    ACCEPT = "text/csv"
+    ACCEPT = ("text/csv", "application/json")
 
     def deserialize(self, stream, content_type):
         """Deserialize CSV or JSON data from an inference endpoint into a pandas
@@ -250,7 +261,7 @@ def deserialize(self, stream, content_type):
 class JSONLinesDeserializer(BaseDeserializer):
     """Deserialize JSON lines data from an inference endpoint."""
 
-    ACCEPT = "application/jsonlines"
+    ACCEPT = ("application/jsonlines",)
 
     def deserialize(self, stream, content_type):
         """Deserialize JSON lines data from an inference endpoint.

src/sagemaker/predictor.py

@@ -121,7 +121,7 @@ def _create_request_args(self, data, initial_args=None, target_model=None, targe
             args["ContentType"] = self.content_type
 
         if "Accept" not in args:
-            args["Accept"] = self.accept
+            args["Accept"] = ", ".join(self.accept)
 
         if target_model:
             args["TargetModel"] = target_model

tests/unit/test_predictor.py

@@ -12,11 +12,13 @@
 # language governing permissions and limitations under the License.
 from __future__ import absolute_import
 
+import io
 import json
 
 import pytest
 from mock import Mock, call, patch
 
+from sagemaker.deserializers import CSVDeserializer, PandasDeserializer
 from sagemaker.predictor import Predictor
 from sagemaker.serializers import JSONSerializer, CSVSerializer
 
@@ -132,7 +134,7 @@ def json_sagemaker_session():
     response_body.close = Mock("close", return_value=None)
     ims.sagemaker_runtime_client.invoke_endpoint = Mock(
         name="invoke_endpoint",
-        return_value={"Body": response_body, "ContentType": DEFAULT_CONTENT_TYPE},
+        return_value={"Body": response_body, "ContentType": "application/json"},
     )
     return ims
 
@@ -168,9 +170,7 @@ def ret_csv_sagemaker_session():
     ims.sagemaker_client.describe_endpoint = Mock(return_value=ENDPOINT_DESC)
     ims.sagemaker_client.describe_endpoint_config = Mock(return_value=ENDPOINT_CONFIG_DESC)
 
-    response_body = Mock("body")
-    response_body.read = Mock("read", return_value=CSV_RETURN_VALUE)
-    response_body.close = Mock("close", return_value=None)
+    response_body = io.BytesIO(bytes(CSV_RETURN_VALUE, "utf-8"))
     ims.sagemaker_runtime_client.invoke_endpoint = Mock(
         name="invoke_endpoint",
         return_value={"Body": response_body, "ContentType": CSV_CONTENT_TYPE},
@@ -180,23 +180,46 @@ def ret_csv_sagemaker_session():
 
 def test_predict_call_with_csv():
     sagemaker_session = ret_csv_sagemaker_session()
-    predictor = Predictor(ENDPOINT, sagemaker_session, serializer=CSVSerializer())
+    predictor = Predictor(
+        ENDPOINT, sagemaker_session, serializer=CSVSerializer(), deserializer=CSVDeserializer()
+    )
 
     data = [1, 2]
     result = predictor.predict(data)
 
     assert sagemaker_session.sagemaker_runtime_client.invoke_endpoint.called
 
     expected_request_args = {
-        "Accept": DEFAULT_ACCEPT,
+        "Accept": CSV_CONTENT_TYPE,
         "Body": "1,2",
         "ContentType": CSV_CONTENT_TYPE,
         "EndpointName": ENDPOINT,
     }
     call_args, kwargs = sagemaker_session.sagemaker_runtime_client.invoke_endpoint.call_args
     assert kwargs == expected_request_args
 
-    assert result == CSV_RETURN_VALUE
+    assert result == [["1", "2", "3"]]
+
+
+def test_predict_call_with_multiple_accept_types():
+    sagemaker_session = ret_csv_sagemaker_session()
+    predictor = Predictor(
+        ENDPOINT, sagemaker_session, serializer=CSVSerializer(), deserializer=PandasDeserializer()
+    )
+
+    data = [1, 2]
+    predictor.predict(data)
+
+    assert sagemaker_session.sagemaker_runtime_client.invoke_endpoint.called
+
+    expected_request_args = {
+        "Accept": "text/csv, application/json",
+        "Body": "1,2",
+        "ContentType": CSV_CONTENT_TYPE,
+        "EndpointName": ENDPOINT,
+    }
+    call_args, kwargs = sagemaker_session.sagemaker_runtime_client.invoke_endpoint.call_args
+    assert kwargs == expected_request_args
 
 
 @patch("sagemaker.predictor.name_from_base")