breaking: Move StringDeserializer to sagemaker.deserializers (#1677)

Author: bveeramani

src/sagemaker/deserializers.py

@@ -41,6 +41,35 @@ def ACCEPT(self):
         """The content type that is expected from the inference endpoint."""
 
 
+class StringDeserializer(BaseDeserializer):
+    """Deserialize data from an inference endpoint into a decoded string."""
+
+    ACCEPT = "application/json"
+
+    def __init__(self, encoding="UTF-8"):
+        """Initialize the string encoding.
+
+        Args:
+            encoding (str): The string encoding to use (default: UTF-8).
+        """
+        self.encoding = encoding
+
+    def deserialize(self, data, content_type):
+        """Deserialize data from an inference endpoint into a decoded string.
+
+        Args:
+            data (object): Data to be deserialized.
+            content_type (str): The MIME type of the data.
+
+        Returns:
+            str: The data deserialized into a decoded string.
+        """
+        try:
+            return data.read().decode(self.encoding)
+        finally:
+            data.close()
+
+
 class BytesDeserializer(BaseDeserializer):
     """Deserialize a stream of bytes into a bytes object."""
 

src/sagemaker/predictor.py

@@ -623,35 +623,6 @@ def __call__(self, stream, content_type):
 csv_deserializer = _CsvDeserializer()
 
 
-class StringDeserializer(object):
-    """Return the response as a decoded string.
-
-    Args:
-        encoding (str): The string encoding to use (default=utf-8).
-        accept (str): The Accept header to send to the server (optional).
-    """
-
-    def __init__(self, encoding="utf-8", accept=None):
-        """
-        Args:
-            encoding:
-            accept:
-        """
-        self.encoding = encoding
-        self.accept = accept
-
-    def __call__(self, stream, content_type):
-        """
-        Args:
-            stream:
-            content_type:
-        """
-        try:
-            return stream.read().decode(self.encoding)
-        finally:
-            stream.close()
-
-
 class StreamDeserializer(object):
     """Returns the tuple of the response stream and the content-type of the response.
        It is the receivers responsibility to close the stream when they're done

tests/integ/test_multidatamodel.py

@@ -24,9 +24,10 @@
 
 from sagemaker import utils
 from sagemaker.amazon.randomcutforest import RandomCutForest
+from sagemaker.deserializers import StringDeserializer
 from sagemaker.multidatamodel import MultiDataModel
 from sagemaker.mxnet import MXNet
-from sagemaker.predictor import Predictor, StringDeserializer, npy_serializer
+from sagemaker.predictor import Predictor, npy_serializer
 from sagemaker.utils import sagemaker_timestamp, unique_name_from_base, get_ecr_image_uri_prefix
 from tests.integ import DATA_DIR, TRAINING_DEFAULT_TIMEOUT_MINUTES
 from tests.integ.retry import retries

tests/unit/sagemaker/test_deserializers.py

@@ -14,7 +14,15 @@
 
 import io
 
-from sagemaker.deserializers import BytesDeserializer
+from sagemaker.deserializers import StringDeserializer, BytesDeserializer
+
+
+def test_string_deserializer():
+    deserializer = StringDeserializer()
+
+    result = deserializer.deserialize(io.BytesIO(b"[1, 2, 3]"), "application/json")
+
+    assert result == "[1, 2, 3]"
 
 
 def test_bytes_deserializer():

tests/unit/test_predictor.py

@@ -26,7 +26,6 @@
     json_deserializer,
     csv_serializer,
     csv_deserializer,
-    StringDeserializer,
     StreamDeserializer,
     numpy_deserializer,
     npy_serializer,
@@ -183,12 +182,6 @@ def test_json_deserializer_invalid_data():
     assert "column" in str(error)
 
 
-def test_string_deserializer():
-    result = StringDeserializer()(io.BytesIO(b"[1, 2, 3]"), "application/json")
-
-    assert result == "[1, 2, 3]"
-
-
 def test_stream_deserializer():
     stream, content_type = StreamDeserializer()(io.BytesIO(b"[1, 2, 3]"), "application/json")
     result = stream.read()