feat: adds matching strategies and moves resolver

cognee/api/v1/cognify/cognify.py

@@ -10,7 +10,7 @@ from cognee.infrastructure.llm import get_max_chunk_tokens
 from cognee.modules.pipelines import run_pipeline
 from cognee.modules.pipelines.tasks.task import Task
 from cognee.modules.chunking.TextChunker import TextChunker
-from cognee.modules.ontology.rdf_xml.OntologyResolver import RDFLibOntologyResolver
+from cognee.modules.ontology.rdf_xml.RDFLibOntologyResolver import RDFLibOntologyResolver
 from cognee.modules.users.models import User
 
 from cognee.tasks.documents import (

cognee/eval_framework/corpus_builder/task_getters/get_default_tasks_by_indices.py

@@ -5,7 +5,7 @@ from cognee.modules.chunking.TextChunker import TextChunker
 from cognee.tasks.graph import extract_graph_from_data
 from cognee.tasks.storage import add_data_points
 from cognee.shared.data_models import KnowledgeGraph
-from cognee.modules.ontology.rdf_xml.OntologyResolver import RDFLibOntologyResolver
+from cognee.modules.ontology.rdf_xml.RDFLibOntologyResolver import RDFLibOntologyResolver
 
 
 async def get_default_tasks_by_indices(

cognee/modules/graph/utils/expand_with_nodes_and_edges.py

@@ -8,7 +8,7 @@ from cognee.modules.engine.utils import (
     generate_node_name,
 )
 from cognee.shared.data_models import KnowledgeGraph
-from cognee.modules.ontology.rdf_xml.OntologyResolver import RDFLibOntologyResolver
+from cognee.modules.ontology.rdf_xml.RDFLibOntologyResolver import RDFLibOntologyResolver
 
 
 def _create_node_key(node_id: str, category: str) -> str:

cognee/modules/ontology/base_ontology_resolver.py

@@ -2,10 +2,20 @@ from abc import ABC, abstractmethod
 from typing import List, Tuple, Optional
 
 from cognee.modules.ontology.models import AttachedOntologyNode
+from cognee.modules.ontology.matching_strategies import MatchingStrategy, FuzzyMatchingStrategy
 
 
 class BaseOntologyResolver(ABC):
     """Abstract base class for ontology resolvers."""
+    
+    def __init__(self, matching_strategy: Optional[MatchingStrategy] = None):
+        """Initialize the ontology resolver with a matching strategy.
+        
+        Args:
+            matching_strategy: The strategy to use for entity matching. 
+                              Defaults to FuzzyMatchingStrategy if None.
+        """
+        self.matching_strategy = matching_strategy or FuzzyMatchingStrategy()
 
     @abstractmethod
     def build_lookup(self) -> None:

cognee/modules/ontology/matching_strategies.py

@@ -0,0 +1,55 @@
+import difflib
+from abc import ABC, abstractmethod
+from typing import List, Optional
+
+
+class MatchingStrategy(ABC):
+    """Abstract base class for ontology entity matching strategies."""
+    
+    @abstractmethod
+    def find_match(self, name: str, candidates: List[str]) -> Optional[str]:
+        """Find the best match for a given name from a list of candidates.
+        
+        Args:
+            name: The name to match
+            candidates: List of candidate names to match against
+            
+        Returns:
+            The best matching candidate name, or None if no match found
+        """
+        pass
+
+
+class FuzzyMatchingStrategy(MatchingStrategy):
+    """Fuzzy matching strategy using difflib for approximate string matching."""
+    
+    def __init__(self, cutoff: float = 0.8):
+        """Initialize fuzzy matching strategy.
+        
+        Args:
+            cutoff: Minimum similarity score (0.0 to 1.0) for a match to be considered valid
+        """
+        self.cutoff = cutoff
+    
+    def find_match(self, name: str, candidates: List[str]) -> Optional[str]:
+        """Find the closest fuzzy match for a given name.
+        
+        Args:
+            name: The normalized name to match
+            candidates: List of normalized candidate names
+            
+        Returns:
+            The best matching candidate name, or None if no match meets the cutoff
+        """
+        if not candidates:
+            return None
+            
+        # Check for exact match first
+        if name in candidates:
+            return name
+            
+        # Find fuzzy match
+        best_match = difflib.get_close_matches(
+            name, candidates, n=1, cutoff=self.cutoff
+        )
+        return best_match[0] if best_match else None

cognee/modules/ontology/rdf_xml/RDFLibOntologyResolver.py

@@ -12,6 +12,7 @@ from cognee.modules.ontology.exceptions import (
 )
 from cognee.modules.ontology.base_ontology_resolver import BaseOntologyResolver
 from cognee.modules.ontology.models import AttachedOntologyNode
+from cognee.modules.ontology.matching_strategies import MatchingStrategy, FuzzyMatchingStrategy
 
 logger = get_logger("OntologyAdapter")
 
@@ -23,7 +24,8 @@ class RDFLibOntologyResolver(BaseOntologyResolver):
     It provides fuzzy matching and subgraph extraction capabilities for ontology entities.
     """
     
-    def __init__(self, ontology_file: Optional[str] = None):
+    def __init__(self, ontology_file: Optional[str] = None, matching_strategy: Optional[MatchingStrategy] = None):
+        super().__init__(matching_strategy)
         self.ontology_file = ontology_file
         try:
             if ontology_file and os.path.exists(ontology_file):
@@ -94,13 +96,8 @@ class RDFLibOntologyResolver(BaseOntologyResolver):
         try:
             normalized_name = name.lower().replace(" ", "_").strip()
             possible_matches = list(self.lookup.get(category, {}).keys())
-            if normalized_name in possible_matches:
+            
-                return normalized_name
+            return self.matching_strategy.find_match(normalized_name, possible_matches)
-
-            best_match = difflib.get_close_matches(
-                normalized_name, possible_matches, n=1, cutoff=0.8
-            )
-            return best_match[0] if best_match else None
         except Exception as e:
             logger.error("Error in find_closest_match: %s", str(e))
             raise FindClosestMatchError() from e

cognee/tasks/graph/extract_graph_from_data.py

@@ -4,7 +4,7 @@ from pydantic import BaseModel
 
 from cognee.infrastructure.databases.graph import get_graph_engine
 from cognee.tasks.storage.add_data_points import add_data_points
-from cognee.modules.ontology.rdf_xml.OntologyResolver import RDFLibOntologyResolver
+from cognee.modules.ontology.rdf_xml.RDFLibOntologyResolver import RDFLibOntologyResolver
 from cognee.modules.chunking.models.DocumentChunk import DocumentChunk
 from cognee.modules.graph.utils import (
     expand_with_nodes_and_edges,

cognee/tasks/graph/extract_graph_from_data_v2.py

@@ -3,7 +3,7 @@ from typing import List
 
 from cognee.modules.chunking.models.DocumentChunk import DocumentChunk
 from cognee.shared.data_models import KnowledgeGraph
-from cognee.modules.ontology.rdf_xml.OntologyResolver import RDFLibOntologyResolver
+from cognee.modules.ontology.rdf_xml.RDFLibOntologyResolver import RDFLibOntologyResolver
 from cognee.tasks.graph.cascade_extract.utils.extract_nodes import extract_nodes
 from cognee.tasks.graph.cascade_extract.utils.extract_content_nodes_and_relationship_names import (
     extract_content_nodes_and_relationship_names,

cognee/tests/unit/modules/ontology/test_ontology_adapter.py

@@ -1,6 +1,6 @@
 import pytest
 from rdflib import Graph, Namespace, RDF, OWL, RDFS
-from cognee.modules.ontology.rdf_xml.OntologyResolver import RDFLibOntologyResolver
+from cognee.modules.ontology.rdf_xml.RDFLibOntologyResolver import RDFLibOntologyResolver
 from cognee.modules.ontology.models import AttachedOntologyNode