fix: DynamoDB key & filter expressions attribute overwrite (#2615)

* fix: DynamoDB key & filter expressions overwrite

Signed-off-by: Anton Kukushkin <[email protected]>

* Empty names/values fixes

Signed-off-by: Anton Kukushkin <[email protected]>

---------

Signed-off-by: Anton Kukushkin <[email protected]>

Author: kukushking

awswrangler/dynamodb/_read.py

@@ -440,6 +440,12 @@ def _convert_condition_base_to_expression(
     key_condition_expression: ConditionBase, is_key_condition: bool, serializer: TypeSerializer
 ) -> dict[str, Any]:
     builder = ConditionExpressionBuilder()
+
+    # Use different namespaces for key and filter conditions
+    if is_key_condition:
+        builder._name_placeholder = "kn"
+        builder._value_placeholder = "kv"
+
     expression = builder.build_expression(key_condition_expression, is_key_condition=is_key_condition)
 
     return _ExpressionTuple(
@@ -692,8 +698,15 @@ def read_items(  # noqa: PLR0912
                 key_condition_expression, is_key_condition=True, serializer=serializer
             )
             kwargs["KeyConditionExpression"] = expression_tuple.condition_expression
-            kwargs["ExpressionAttributeNames"] = expression_tuple.attribute_name_placeholders
-            kwargs["ExpressionAttributeValues"] = expression_tuple.attribute_value_placeholders
+
+            kwargs["ExpressionAttributeNames"] = {
+                **kwargs.get("ExpressionAttributeNames", {}),
+                **expression_tuple.attribute_name_placeholders,
+            }
+            kwargs["ExpressionAttributeValues"] = {
+                **kwargs.get("ExpressionAttributeValues", {}),
+                **expression_tuple.attribute_value_placeholders,
+            }
 
     if filter_expression:
         if isinstance(filter_expression, str):
@@ -703,15 +716,28 @@ def read_items(  # noqa: PLR0912
                 filter_expression, is_key_condition=False, serializer=serializer
             )
             kwargs["FilterExpression"] = expression_tuple.condition_expression
-            kwargs["ExpressionAttributeNames"] = expression_tuple.attribute_name_placeholders
-            kwargs["ExpressionAttributeValues"] = expression_tuple.attribute_value_placeholders
+
+            kwargs["ExpressionAttributeNames"] = {
+                **kwargs.get("ExpressionAttributeNames", {}),
+                **expression_tuple.attribute_name_placeholders,
+            }
+            kwargs["ExpressionAttributeValues"] = {
+                **kwargs.get("ExpressionAttributeValues", {}),
+                **expression_tuple.attribute_value_placeholders,
+            }
 
     if columns:
         kwargs["ProjectionExpression"] = ", ".join(columns)
     if expression_attribute_names:
-        kwargs["ExpressionAttributeNames"] = expression_attribute_names
+        kwargs["ExpressionAttributeNames"] = {
+            **kwargs.get("ExpressionAttributeNames", {}),
+            **expression_attribute_names,
+        }
     if expression_attribute_values:
-        kwargs["ExpressionAttributeValues"] = _serialize_item(expression_attribute_values, serializer)
+        kwargs["ExpressionAttributeValues"] = {
+            **kwargs.get("ExpressionAttributeValues", {}),
+            **_serialize_item(expression_attribute_values, serializer),
+        }
     if max_items_evaluated:
         kwargs["Limit"] = max_items_evaluated
 

tests/unit/test_dynamodb.py

@@ -729,3 +729,38 @@ def test_deserialization_full_scan(params: dict[str, Any], dynamodb_table: str)
     assert items_df.iloc[0]["par1"] == "foo"
     assert items_df.iloc[1]["par0"] == 1
     assert items_df.iloc[1]["par1"] == "bar"
+
+
+@pytest.mark.parametrize(
+    "params",
+    [
+        {
+            "KeySchema": [{"AttributeName": "par0", "KeyType": "HASH"}, {"AttributeName": "par1", "KeyType": "RANGE"}],
+            "AttributeDefinitions": [
+                {"AttributeName": "par0", "AttributeType": "N"},
+                {"AttributeName": "par1", "AttributeType": "S"},
+            ],
+        }
+    ],
+)
+@pytest.mark.parametrize("use_threads", [True, False])
+def test_read_items_expressions(params: dict[str, Any], dynamodb_table: str, use_threads: bool) -> None:
+    df = pd.DataFrame(
+        {
+            "par0": [1, 1, 2],
+            "par1": ["a", "b", "c"],
+            "operator": ["Ali", "Sarah", "Eido"],
+            "volume": [100, 200, 300],
+            "compliant": [True, False, False],
+        }
+    )
+    wr.dynamodb.put_df(df=df, table_name=dynamodb_table)
+
+    # KeyConditionExpression as Key
+    df2 = wr.dynamodb.read_items(
+        table_name=dynamodb_table,
+        key_condition_expression=(Key("par0").eq(1) & Key("par1").eq("b")),
+        filter_expression=Attr("operator").eq("Sarah"),
+        use_threads=use_threads,
+    )
+    assert df2.shape == (1, len(df.columns))