added custom dict serializer

app/serializers/__init__.py

@@ -1,6 +1,11 @@
 import json
 
-from . import default_serializer, numpy_serializer, pandas_serializer
+from . import (
+    default_serializer,
+    dictionary_serializer,
+    numpy_serializer,
+    pandas_serializer,
+)
 from .framework import Serializer, custom_encoder, serializers
 
 

app/serializers/dictionary_serializer.py

@@ -0,0 +1,25 @@
+from .framework import Serializer, custom_decoder
+
+
+class DictionarySerializer(Serializer):
+    name = "custom_dict_serializer"
+
+    @classmethod
+    def serialize(cls, obj):
+        # Convert dictionary with non-string keys (e.g., datetime) to a list of
+        # [key, value] pairs
+        items = [[k, v] for k, v in obj.items()]
+        return {
+            "data": items,
+            "serializer": cls.name,
+        }
+
+    @classmethod
+    def deserialize(cls, payload):
+        # Convert back from list of pairs to dictionary
+        items = payload["data"]
+        return {custom_decoder(k): custom_decoder(v) for k, v in items}
+
+
+# Register the serializer for dict type
+DictionarySerializer.register(dict)

tests/test_serializers.py

@@ -119,6 +119,12 @@ def test_dict_of_ndarray():
     assert_array_equal(data1["arr1"], data2["arr2"])
 
 
+def test_dict_with_datetime_keys():
+    assert {dt.datetime(2000, 1, 1): dt.datetime(2000, 1, 1)} == deserialize(
+        serialize({dt.datetime(2000, 1, 1): dt.datetime(2000, 1, 1)})
+    )
+
+
 def test_list_of_ndarray():
     arr1 = np.array([[1.1, 2.2, 3.3], [4.4, 5.5, 6.6]])
     arr2 = np.array([[1.1, 2.2, 3.3], [4.4, 5.5, 6.6]])