Add support for IS_EMPTY metadata filters to Weaviate Vector Store in…

…tegration (#17128)

* Add support for IS_EMPTY to Weaviate Vector Store integration

* Bump lama-index-vector-stores-weaviate version to 1.2.2

llama-index-integrations/vector_stores/llama-index-vector-stores-weaviate/llama_index/vector_stores/weaviate/base.py

@@ -62,6 +62,8 @@ def _transform_weaviate_filter_operator(operator: str) -> str:
         return "contains_any"
     elif operator == "all":
         return "contains_all"
+    elif operator == "is_empty":
+        return "is_none"
     else:
         raise ValueError(f"Filter operator {operator} not supported")
 
@@ -78,12 +80,17 @@ def _to_weaviate_filter(
             if isinstance(filter, MetadataFilters):
                 filters_list.append(_to_weaviate_filter(filter))
                 continue
-            filters_list.append(
-                getattr(
-                    wvc.query.Filter.by_property(filter.key),
-                    _transform_weaviate_filter_operator(filter.operator),
-                )(filter.value)
+
+            property_filter = getattr(
+                wvc.query.Filter.by_property(filter.key),
+                _transform_weaviate_filter_operator(filter.operator),
             )
+            value = filter.value
+            # IS_EMPTY does not take a value (expected to be set to None), but when using IsNull with Weaviate, a
+            # boolean is expected (True meaning the value actually being null / not set / empty)
+            if filter.operator == "is_empty":
+                value = True
+            filters_list.append(property_filter(value))
     else:
         return {}
 

llama-index-integrations/vector_stores/llama-index-vector-stores-weaviate/pyproject.toml

@@ -27,7 +27,7 @@ exclude = ["**/BUILD"]
 license = "MIT"
 name = "llama-index-vector-stores-weaviate"
 readme = "README.md"
-version = "1.2.1"
+version = "1.2.2"
 
 [tool.poetry.dependencies]
 python = ">=3.9,<4.0"

llama-index-integrations/vector_stores/llama-index-vector-stores-weaviate/tests/test_vector_stores_weaviate.py

@@ -132,6 +132,14 @@ def test_to_weaviate_filter_with_various_operators():
     assert filter.operator == "LessThanEqual"
     assert filter.value == 1
 
+    filters = MetadataFilters(
+        filters=[MetadataFilter(key="a", value=None, operator=FilterOperator.IS_EMPTY)]
+    )
+    filter = _to_weaviate_filter(filters)
+    assert filter.target == "a"
+    assert filter.operator == "IsNull"
+    assert filter.value is True
+
 
 def test_to_weaviate_filter_with_multiple_filters():
     filters = MetadataFilters(