From 539707e50ecc0bb2318bea02bd3a9508ec90d8b3 Mon Sep 17 00:00:00 2001
From: SageMaker Bot <49924207+sagemaker-bot@users.noreply.github.com>
Date: Mon, 1 Jun 2026 00:13:31 -0700
Subject: [PATCH] fix: _serialize_dict drops empty string values from
 environment variables (5568)

---
 .../src/sagemaker/core/utils/utils.py         | 27 ++++++++-------
 .../tests/unit/generated/test_utils.py        | 34 +++++++++++++++++--
 2 files changed, 46 insertions(+), 15 deletions(-)

diff --git a/sagemaker-core/src/sagemaker/core/utils/utils.py b/sagemaker-core/src/sagemaker/core/utils/utils.py
index b22f662cc0..dc46e4659d 100644
--- a/sagemaker-core/src/sagemaker/core/utils/utils.py
+++ b/sagemaker-core/src/sagemaker/core/utils/utils.py
@@ -360,22 +360,17 @@ def __init__(
             logger.debug("No config provided. Using default config.")
             config = Config(retries={"max_attempts": 10, "mode": "standard"})
 
-        self.config = Config(user_agent_extra=get_user_agent_extra_suffix())
+        # Merge the provided config with user_agent_extra suffix
+        self.config = config.merge(Config(user_agent_extra=get_user_agent_extra_suffix()))
         self.session = session
         self.region_name = region_name
-        # Read region from environment variable, default to us-west-2
-        import os
-        env_region = os.environ.get('SAGEMAKER_REGION', region_name)
-        env_stage = os.environ.get('SAGEMAKER_STAGE', 'prod')  # default to gamma
-        logger.info(f"Runs on sagemaker {env_stage}, region:{env_region}")
-
 
         self.sagemaker_client = session.client(
             "sagemaker",
-            region_name=env_region,
+            region_name=region_name,
             config=self.config,
         )
-        
+
         self.sagemaker_runtime_client = session.client(
             "sagemaker-runtime", region_name, config=self.config
         )
@@ -538,7 +533,9 @@ def _serialize_dict(value: Dict) -> dict:
         dict: The serialized dict
     """
     serialized_dict = {}
-    # Drop only Unassigned/None; preserve valid falsy values like False, 0, "".
+    # Drop only Unassigned/None; preserve valid falsy values like False, 0, "", [], {}.
+    # Note: empty containers ([] and {}) are now preserved where previously they were
+    # filtered as falsy. This is intentional to correctly handle all non-None values.
     for k, v in value.items():
         serialize_result = serialize(v)
         if serialize_result is not None:
@@ -557,7 +554,9 @@ def _serialize_list(value: List) -> list:
         list: The serialized list
     """
     serialized_list = []
-    # Drop only Unassigned/None; preserve valid falsy values like False, 0, "".
+    # Drop only Unassigned/None; preserve valid falsy values like False, 0, "", [], {}.
+    # Note: empty containers ([] and {}) are now preserved where previously they were
+    # filtered as falsy. This is intentional to correctly handle all non-None values.
     for v in value:
         serialize_result = serialize(v)
         if serialize_result is not None:
@@ -576,8 +575,12 @@ def _serialize_shape(value: Any) -> dict:
         dict: The dict of serialized shape
     """
     serialized_dict = {}
+    # Drop only Unassigned/None; preserve valid falsy values like False, 0, "", [], {}.
+    # Note: empty containers ([] and {}) are now preserved where previously they were
+    # filtered as falsy. This is intentional to correctly handle all non-None values.
     for k, v in vars(value).items():
-        if serialize_result := serialize(v):
+        serialize_result = serialize(v)
+        if serialize_result is not None:
             key = snake_to_pascal(k) if is_snake_case(k) else k
             serialized_dict.update({key[0].upper() + key[1:]: serialize_result})
     return serialized_dict
diff --git a/sagemaker-core/tests/unit/generated/test_utils.py b/sagemaker-core/tests/unit/generated/test_utils.py
index 0928f09b68..79649594a0 100644
--- a/sagemaker-core/tests/unit/generated/test_utils.py
+++ b/sagemaker-core/tests/unit/generated/test_utils.py
@@ -8,7 +8,18 @@
     TrialComponent,
     TrialComponentParameterValue,
 )
-from sagemaker.core.utils.utils import *
+from sagemaker.core.utils.utils import (
+    configure_logging,
+    is_snake_case,
+    snake_to_pascal,
+    pascal_to_snake,
+    is_not_primitive,
+    is_primitive_class,
+    serialize,
+    ResourceIterator,
+    SageMakerClient,
+    Unassigned,
+)
 
 
 LIST_TRAINING_JOB_RESPONSE_WITH_NEXT_TOKEN = {
@@ -266,7 +277,6 @@ def test_next_with_custom_key_mapping(resource_iterator_with_custom_key_mapping)
             try:
                 next_item = next(iterator)
                 assert isinstance(next_item, DataQualityJobDefinition)
-                print(next_item)
                 expected_data_quality_job_definition_data = (
                     LIST_DATA_QUALITY_JOB_DEFINITION_RESPONSE_WITHOUT_NEXT_TOKEN[
                         "JobDefinitionSummaries"
@@ -303,7 +313,6 @@ def test_next_with_primitive_class(resource_iterator_with_primitive_class):
         try:
             next_item = next(iterator)
             assert isinstance(next_item, str)
-            print(next_item)
             expected_image_version_alias_data = LIST_ALIASES_RESPONSE_WITHOUT_NEXT_TOKEN[
                 "SageMakerImageVersionAliases"
             ][index]
@@ -387,6 +396,25 @@ def test_serialize_method_nested_shape():
     }
 
 
+def test_serialize_shape_preserves_falsy_attribute_values():
+    """Regression: _serialize_shape should preserve falsy values like empty string, 0, False."""
+    # TrialComponentParameterValue with number_value=0 should preserve the 0
+    param_zero = TrialComponentParameterValue(number_value=0)
+    serialized = serialize(param_zero)
+    assert serialized["NumberValue"] == 0
+
+    # TrialComponentParameterValue with string_value="" should preserve the empty string
+    param_empty_str = TrialComponentParameterValue(string_value="")
+    serialized = serialize(param_empty_str)
+    assert serialized["StringValue"] == ""
+
+    # Test that Unassigned values are still excluded
+    param_unassigned = TrialComponentParameterValue()
+    serialized = serialize(param_unassigned)
+    assert "NumberValue" not in serialized
+    assert "StringValue" not in serialized
+
+
 class TestUnassignedBehavior:
     """Test Unassigned class methods for proper behavior.