fix: use different separator to flatten dict (aws#4629)

Author: Captainia

src/sagemaker/utils.py

@@ -1605,7 +1605,7 @@ def can_model_package_source_uri_autopopulate(source_uri: str):
     )
 
 
-def flatten_dict(source_dict: Dict[str, Any], sep: str = ".") -> Dict[str, Any]:
+def flatten_dict(source_dict: Dict[str, Any], sep: str = "^") -> Dict[str, Any]:
     """Flatten a nested dictionary.
 
     Args:
@@ -1620,7 +1620,7 @@ def flatten_dict(source_dict: Dict[str, Any], sep: str = ".") -> Dict[str, Any]:
     return {}
 
 
-def unflatten_dict(source_dict: Dict[str, Any], sep: str = ".") -> Dict[str, Any]:
+def unflatten_dict(source_dict: Dict[str, Any], sep: str = "^") -> Dict[str, Any]:
     """Unflatten a flattened dictionary back into a nested dictionary.
 
     Args:

tests/unit/test_utils.py

@@ -1819,7 +1819,7 @@ def test_can_model_package_source_uri_autopopulate():
 class TestDeepMergeDict(TestCase):
     def test_flatten_dict_basic(self):
         nested_dict = {"a": 1, "b": {"x": 2, "y": {"p": 3, "q": 4}}, "c": 5}
-        flattened_dict = {"a": 1, "b.x": 2, "b.y.p": 3, "b.y.q": 4, "c": 5}
+        flattened_dict = {"a": 1, "b^x": 2, "b^y^p": 3, "b^y^q": 4, "c": 5}
         self.assertDictEqual(flatten_dict(nested_dict), flattened_dict)
         self.assertDictEqual(unflatten_dict(flattened_dict), nested_dict)
 
@@ -1837,7 +1837,7 @@ def test_flatten_dict_no_nested(self):
 
     def test_flatten_dict_with_various_types(self):
         nested_dict = {"a": [1, 2, 3], "b": {"x": None, "y": {"p": [], "q": ""}}, "c": 9}
-        flattened_dict = {"a": [1, 2, 3], "b.x": None, "b.y.p": [], "b.y.q": "", "c": 9}
+        flattened_dict = {"a": [1, 2, 3], "b^x": None, "b^y^p": [], "b^y^q": "", "c": 9}
         self.assertDictEqual(flatten_dict(nested_dict), flattened_dict)
         self.assertDictEqual(unflatten_dict(flattened_dict), nested_dict)