From ddcda3e8ac5e88eb553b185bf0acaf53a6162949 Mon Sep 17 00:00:00 2001
From: aviruthen <91846056+aviruthen@users.noreply.github.com>
Date: Thu, 26 Mar 2026 13:21:31 -0400
Subject: [PATCH 1/2] fix: Attempting to serialize bytes type causes error
 (#5660)

---
 .../src/sagemaker/core/utils/utils.py         |  4 ++--
 .../tests/unit/generated/test_utils.py        | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/sagemaker-core/src/sagemaker/core/utils/utils.py b/sagemaker-core/src/sagemaker/core/utils/utils.py
index 8a8d90be6e..86ebf8160f 100644
--- a/sagemaker-core/src/sagemaker/core/utils/utils.py
+++ b/sagemaker-core/src/sagemaker/core/utils/utils.py
@@ -273,7 +273,7 @@ def pascal_to_snake(pascal_str):
 
 
 def is_not_primitive(obj):
-    return not isinstance(obj, (int, float, str, bool, datetime.datetime))
+        return not isinstance(obj, (int, float, str, bool, bytes, datetime.datetime))
 
 
 def is_not_str_dict(obj):
@@ -285,7 +285,7 @@ def is_primitive_list(obj):
 
 
 def is_primitive_class(cls):
-    return cls in (str, int, bool, float, datetime.datetime)
+        return cls in (str, int, bool, float, bytes, datetime.datetime)
 
 
 class Unassigned:
diff --git a/sagemaker-core/tests/unit/generated/test_utils.py b/sagemaker-core/tests/unit/generated/test_utils.py
index 44856d17d5..5005f7bed5 100644
--- a/sagemaker-core/tests/unit/generated/test_utils.py
+++ b/sagemaker-core/tests/unit/generated/test_utils.py
@@ -373,6 +373,25 @@ def test_serialize_method_nested_shape():
     }
 
 
+
+def test_serialize_with_bytes_value_returns_bytes():
+    result = serialize({'body': b'1'})
+    assert result == {'body': b'1'}
+
+
+def test_serialize_with_bytes_in_list():
+    result = serialize([b'hello', b'world'])
+    assert result == [b'hello', b'world']
+
+
+def test_is_not_primitive_with_bytes_returns_false():
+    assert is_not_primitive(b'test') is False
+
+
+def test_is_primitive_class_with_bytes_returns_true():
+    assert is_primitive_class(bytes) is True
+
+
 class TestUnassignedBehavior:
     """Test Unassigned class methods for proper behavior.
     

From e871aa831cead8d1a0187caf0a0bfdaac66bbaad Mon Sep 17 00:00:00 2001
From: aviruthen <91846056+aviruthen@users.noreply.github.com>
Date: Thu, 26 Mar 2026 13:25:35 -0400
Subject: [PATCH 2/2] fix: address review comments (iteration #1)

---
 .../tests/unit/generated/test_utils.py          | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/sagemaker-core/tests/unit/generated/test_utils.py b/sagemaker-core/tests/unit/generated/test_utils.py
index 5005f7bed5..67808c9b02 100644
--- a/sagemaker-core/tests/unit/generated/test_utils.py
+++ b/sagemaker-core/tests/unit/generated/test_utils.py
@@ -373,22 +373,21 @@ def test_serialize_method_nested_shape():
     }
 
 
+def test_serialize_bytes_returns_bytes_as_is():
+    result = serialize(b'1')
+    assert result == b'1'
 
-def test_serialize_with_bytes_value_returns_bytes():
+
+def test_serialize_dict_with_bytes_value():
     result = serialize({'body': b'1'})
     assert result == {'body': b'1'}
 
 
-def test_serialize_with_bytes_in_list():
-    result = serialize([b'hello', b'world'])
-    assert result == [b'hello', b'world']
-
-
-def test_is_not_primitive_with_bytes_returns_false():
-    assert is_not_primitive(b'test') is False
+def test_is_not_primitive_with_bytes():
+    assert is_not_primitive(b'hello') is False
 
 
-def test_is_primitive_class_with_bytes_returns_true():
+def test_is_primitive_class_with_bytes():
     assert is_primitive_class(bytes) is True