Support dicts in lists in metadata (#148)

* Support dicts in lists in metadata

This allows cases like:

```
metadata = {
    "entities": [
        {"entity": "Bell", "type": "PEOPLE"},
        ...
    ]
}
```

Note: For stores that perform shredding this works by JSON encoding the
entire item `{"entity": "Bell", "type": "PEOPLE"}` into the key. This
means that equality on the items of `entities` are supported, by digging
into fields won't be.

* lint/fmt

* lint

data/animals.jsonl

@@ -1,5 +1,5 @@
-{"id": "aardvark", "text": "the aardvark is a nocturnal mammal known for its burrowing habits and long snout used to sniff out ants.", "metadata": {"type": "mammal", "number_of_legs": 4, "keywords": ["burrowing", "nocturnal", "ants", "savanna"], "habitat": "savanna"}}
-{"id": "albatross", "text": "the albatross is a large seabird with the longest wingspan of any bird, allowing it to glide effortlessly over oceans.", "metadata": {"type": "bird", "number_of_legs": 2, "keywords": ["seabird", "wingspan", "ocean"], "habitat": "marine"}}
+{"id": "aardvark", "text": "the aardvark is a nocturnal mammal known for its burrowing habits and long snout used to sniff out ants.", "metadata": {"type": "mammal", "number_of_legs": 4, "keywords": ["burrowing", "nocturnal", "ants", "savanna"], "habitat": "savanna", "tags": [{"a": 5, "b": 7}, {"a": 8, "b": 10}]}}
+{"id": "albatross", "text": "the albatross is a large seabird with the longest wingspan of any bird, allowing it to glide effortlessly over oceans.", "metadata": {"type": "bird", "number_of_legs": 2, "keywords": ["seabird", "wingspan", "ocean"], "habitat": "marine", "tags": [{"a": 5, "b": 8}, {"a": 8, "b": 10}]}}
 {"id": "alligator", "text": "alligators are large reptiles with powerful jaws and are commonly found in freshwater wetlands.", "metadata": {"type": "reptile", "number_of_legs": 4, "keywords": ["reptile", "jaws", "wetlands"], "diet": "carnivorous", "nested": { "a": 5 }}}
 {"id": "alpaca", "text": "alpacas are domesticated mammals valued for their soft wool and friendly demeanor.", "metadata": {"type": "mammal", "number_of_legs": 4, "keywords": ["wool", "domesticated", "friendly"], "origin": "south america", "nested": { "a": 5 }}}
 {"id": "ant", "text": "ants are social insects that live in colonies and are known for their teamwork and strength.", "metadata": {"type": "insect", "number_of_legs": 6, "keywords": ["social", "colonies", "strength", "pollinator"], "diet": "omnivorous", "nested": { "a": 6 }}}

packages/graph-retriever/pyproject.toml

@@ -42,6 +42,7 @@ dependencies = [
     "numpy>=1.26.4",
     "typing-extensions>=4.12.2",
     "pytest>=8.3.4",
+    "immutabledict>=4.2.1",
 ]
 
 [project.urls]

packages/graph-retriever/src/graph_retriever/adapters/base.py

@@ -5,6 +5,8 @@
 from collections.abc import Iterable, Sequence
 from typing import Any
 
+from immutabledict import immutabledict
+
 from graph_retriever.content import Content
 from graph_retriever.edges import Edge, IdEdge, MetadataEdge
 from graph_retriever.utils.run_in_executor import run_in_executor
@@ -355,8 +357,8 @@ async def aadjacent(
 
     def _metadata_filter(
         self,
+        edge: Edge,
         base_filter: dict[str, Any] | None = None,
-        edge: Edge | None = None,
     ) -> dict[str, Any]:
         """
         Return a filter for the `base_filter` and incoming edges from `edge`.
@@ -376,10 +378,8 @@ def _metadata_filter(
         :
             The metadata dictionary to use for the given filter.
         """
-        metadata_filter = {**(base_filter or {})}
         assert isinstance(edge, MetadataEdge)
-        if edge is None:
-            metadata_filter
-        else:
-            metadata_filter[edge.incoming_field] = edge.value
-        return metadata_filter
+        value = edge.value
+        if isinstance(value, immutabledict):
+            value = dict(value)
+        return {edge.incoming_field: value, **(base_filter or {})}

packages/graph-retriever/src/graph_retriever/edges/_base.py

@@ -3,6 +3,8 @@
 from dataclasses import dataclass
 from typing import Any, TypeAlias
 
+from immutabledict import immutabledict
+
 from graph_retriever import Content
 
 
@@ -34,6 +36,17 @@ class MetadataEdge(Edge):
         The value associated with the key for this edge
     """
 
+    def __init__(self, incoming_field: str, value: Any) -> None:
+        # `self.field = value` and `setattr(self, "field", value)` -- don't work
+        # because of frozen. we need to call `__setattr__` directly (as the
+        # default `__init__` would do) to initialize the fields of the frozen
+        # dataclass.
+        object.__setattr__(self, "incoming_field", incoming_field)
+
+        if isinstance(value, dict):
+            value = immutabledict(value)
+        object.__setattr__(self, "value", value)
+
     incoming_field: str
     value: Any
 

packages/graph-retriever/src/graph_retriever/testing/adapter_tests.py

@@ -56,7 +56,9 @@ class AdapterComplianceCase(abc.ABC):
 
     id: str
     expected: list[str]
+
     requires_nested: bool = False
+    requires_dict_in_list: bool = False
 
 
 @dataclass
@@ -191,6 +193,50 @@ class AdjacentCase(AdapterComplianceCase):
             "horse",
         ],
     ),
+    AdjacentCase(
+        id="numeric",
+        query="domesticated hunters",
+        edges={
+            MetadataEdge("number_of_legs", 0),
+        },
+        k=20,  # more than match the filter so we get all
+        expected=[
+            "barracuda",
+            "cobra",
+            "dolphin",
+            "eel",
+            "fish",
+            "jellyfish",
+            "manatee",
+            "narwhal",
+        ],
+    ),
+    AdjacentCase(
+        id="two_edges_diff_field",
+        query="domesticated hunters",
+        edges={
+            MetadataEdge("type", "reptile"),
+            MetadataEdge("number_of_legs", 0),
+        },
+        k=20,  # more than match the filter so we get all
+        expected=[
+            "alligator",
+            "barracuda",
+            "chameleon",
+            "cobra",
+            "crocodile",
+            "dolphin",
+            "eel",
+            "fish",
+            "gecko",
+            "iguana",
+            "jellyfish",
+            "komodo dragon",
+            "lizard",
+            "manatee",
+            "narwhal",
+        ],
+    ),
     AdjacentCase(
         id="one_ids",
         query="domesticated hunters",
@@ -262,6 +308,39 @@ class AdjacentCase(AdapterComplianceCase):
             "komodo dragon",  # reptile
         ],
     ),
+    AdjacentCase(
+        id="dict_in_list",
+        query="domesticated hunters",
+        edges={
+            MetadataEdge("tags", {"a": 5, "b": 7}),
+        },
+        expected=[
+            "aardvark",
+        ],
+        requires_dict_in_list=True,
+    ),
+    AdjacentCase(
+        id="dict_in_list_multiple",
+        query="domesticated hunters",
+        edges={
+            MetadataEdge("tags", {"a": 5, "b": 7}),
+            MetadataEdge("tags", {"a": 5, "b": 8}),
+        },
+        expected=[
+            "aardvark",
+            "albatross",
+        ],
+        requires_dict_in_list=True,
+    ),
+    AdjacentCase(
+        id="absent_dict",
+        query="domesticated hunters",
+        edges={
+            MetadataEdge("tags", {"a": 5, "b": 10}),
+        },
+        expected=[],
+        requires_dict_in_list=True,
+    ),
     AdjacentCase(
         id="nested",
         query="domesticated hunters",
@@ -318,6 +397,10 @@ def supports_nested_metadata(self) -> bool:
         """Return whether nested metadata is expected to work."""
         return True
 
+    def supports_dict_in_list(self) -> bool:
+        """Return whether dicts can appear in list fields in metadata."""
+        return True
+
     def expected(self, method: str, case: AdapterComplianceCase) -> list[str]:
         """
         Override to change the expected behavior of a case.
@@ -346,6 +429,8 @@ def expected(self, method: str, case: AdapterComplianceCase) -> list[str]:
         """
         if not self.supports_nested_metadata() and case.requires_nested:
             pytest.xfail("nested metadata not supported")
+        if not self.supports_dict_in_list() and case.requires_dict_in_list:
+            pytest.xfail("dict-in-list fields is not supported")
         return case.expected
 
     @pytest.fixture(params=GET_CASES, ids=lambda c: c.id)

packages/langchain-graph-retriever/pyproject.toml

@@ -42,6 +42,7 @@ classifiers = [
 dependencies = [
     "backoff>=2.2.1",
     "graph-retriever",
+    "immutabledict>=4.2.1",
     "langchain-core>=0.3.29",
     "networkx>=3.4.2",
     "pydantic>=2.10.4",

packages/langchain-graph-retriever/src/langchain_graph_retriever/adapters/astra.py

@@ -12,6 +12,7 @@
 from graph_retriever.utils import merge
 from graph_retriever.utils.batched import batched
 from graph_retriever.utils.top_k import top_k
+from immutabledict import immutabledict
 from typing_extensions import override
 
 try:
@@ -107,13 +108,27 @@ def with_user_filters(
         ) -> dict[str, Any]:
             return filter if encoded else codec.encode_filter(filter)
 
+    def process_value(v: Any) -> Any:
+        if isinstance(v, immutabledict):
+            return dict(v)
+        else:
+            return v
+
     for k, v in metadata.items():
         for v_batch in batched(v, 100):
-            batch = list(v_batch)
-            if len(batch) == 1:
-                yield (with_user_filters({k: batch[0]}, encoded=False))
+            batch = [process_value(v) for v in v_batch]
+            if isinstance(batch[0], dict):
+                if len(batch) == 1:
+                    yield with_user_filters({k: {"$all": [batch[0]]}}, encoded=False)
+                else:
+                    yield with_user_filters(
+                        {"$or": [{k: {"$all": [v]}} for v in batch]}, encoded=False
+                    )
             else:
-                yield (with_user_filters({k: {"$in": batch}}, encoded=False))
+                if len(batch) == 1:
+                    yield (with_user_filters({k: batch[0]}, encoded=False))
+                else:
+                    yield (with_user_filters({k: {"$in": batch}}, encoded=False))
 
     for id_batch in batched(ids, 100):
         ids = list(id_batch)

packages/langchain-graph-retriever/src/langchain_graph_retriever/adapters/langchain.py

@@ -6,7 +6,6 @@
 
 from graph_retriever import Content
 from graph_retriever.adapters import Adapter
-from graph_retriever.edges import Edge, MetadataEdge
 from langchain_core.documents import Document
 from langchain_core.embeddings import Embeddings
 from langchain_core.runnables import run_in_executor
@@ -358,37 +357,6 @@ async def _aget(
             **kwargs,
         )
 
-    def _metadata_filter(
-        self,
-        base_filter: dict[str, Any] | None = None,
-        edge: Edge | None = None,
-    ) -> dict[str, Any]:
-        """
-        Return a filter for the `base_filter` and incoming edges from `edge`.
-
-        Parameters
-        ----------
-        base_filter :
-            Any base metadata filter that should be used for search.
-            Generally corresponds to the user specified filters for the entire
-            traversal. Should be combined with the filters necessary to support
-            nodes with an *incoming* edge matching `edge`.
-        edge :
-            An optional edge which should be added to the filter.
-
-        Returns
-        -------
-        :
-            The metadata dictionary to use for the given filter.
-        """
-        metadata_filter = {**(base_filter or {})}
-        assert isinstance(edge, MetadataEdge)
-        if edge is None:
-            metadata_filter
-        else:
-            metadata_filter[edge.incoming_field] = edge.value
-        return metadata_filter
-
 
 class ShreddedLangchainAdapter(LangchainAdapter[StoreT]):
     """

packages/langchain-graph-retriever/src/langchain_graph_retriever/adapters/open_search.py

@@ -54,7 +54,7 @@ def __init__(self, vector_store: OpenSearchVectorSearch):
             self._id_field = "_id"
 
     def _build_filter(
-        self, filter: dict[str, str] | None = None
+        self, filter: dict[str, Any] | None = None
     ) -> list[dict[str, Any]] | None:
         """
         Build a filter query for OpenSearch based on metadata.
@@ -68,17 +68,24 @@ def _build_filter(
         -------
         :
             Filter query for OpenSearch.
+
+        Raises
+        ------
+        ValueError
+            If the query is not supported by OpenSearch adapter.
         """
         if filter is None:
             return None
-        return [
-            {
-                "terms" if isinstance(value, list) else "term": {
-                    f"metadata.{key}.keyword": value
-                }
-            }
-            for key, value in filter.items()
-        ]
+
+        filters = []
+        for key, value in filter.items():
+            if isinstance(value, list):
+                filters.append({"terms": {f"metadata.{key}": value}})
+            elif isinstance(value, dict):
+                raise ValueError("Open Search doesn't suport dictionary searches.")
+            else:
+                filters.append({"term": {f"metadata.{key}": value}})
+        return filters
 
     @override
     def _search(
@@ -92,9 +99,8 @@ def _search(
             # use an efficient_filter to collect results that
             # are near the embedding vector until up to 'k'
             # documents that match the filter are found.
-            kwargs["efficient_filter"] = {
-                "bool": {"must": self._build_filter(filter=filter)}
-            }
+            query = {"bool": {"must": self._build_filter(filter=filter)}}
+            kwargs["efficient_filter"] = query
 
         if k == 0:
             return []

packages/langchain-graph-retriever/src/langchain_graph_retriever/transformers/shredding.py

@@ -110,9 +110,10 @@ def restore_documents(
                     and value == self.static_value
                 ):
                     original_key, original_value = split_key
+                    value = json.loads(original_value)
                     if original_key not in new_doc.metadata:
                         new_doc.metadata[original_key] = []
-                    new_doc.metadata[original_key].append(original_value)
+                    new_doc.metadata[original_key].append(value)
                 else:
                     # Retain non-shredded metadata as is
                     new_doc.metadata[key] = value
@@ -137,7 +138,7 @@ def shredded_key(self, key: str, value: Any) -> str:
         str
             the shredded key
         """
-        return f"{key}{self.path_delimiter}{value}"
+        return f"{key}{self.path_delimiter}{json.dumps(value)}"
 
     def shredded_value(self) -> str:
         """

packages/langchain-graph-retriever/tests/adapters/test_astra.py

@@ -212,7 +212,8 @@ def astra_config(enabled_stores: set[str]) -> Iterator[_AstraConfig | None]:
     assert found, f"Keyspace '{keyspace}' not created"
     yield _AstraConfig(token=token, keyspace=keyspace, api_endpoint=api_endpoint)
 
-    admin.drop_keyspace(keyspace)
+    if keyspace != "default_keyspace":
+        admin.drop_keyspace(keyspace)
 
 
 class TestAstraAdapter(AdapterComplianceSuite):

packages/langchain-graph-retriever/tests/adapters/test_cassandra.py

@@ -83,7 +83,7 @@ def adapter(
         )
         docs = list(shredder.transform_documents(animal_docs))
         store.add_documents(docs)
-        yield CassandraAdapter(store, shredder, {"keywords"})
+        yield CassandraAdapter(store, shredder, {"keywords", "tags"})
 
         if session:
             session.shutdown()

packages/langchain-graph-retriever/tests/adapters/test_chroma.py

@@ -48,6 +48,8 @@ def remove_nested_metadata(doc: Document) -> Document:
             collection_metadata={"hnsw:space": "cosine"},
         )
 
-        yield ChromaAdapter(store, shredder, nested_metadata_fields={"keywords"})
+        yield ChromaAdapter(
+            store, shredder, nested_metadata_fields={"keywords", "tags"}
+        )
 
         store.delete_collection()