from typing import List, Optional from langchain.graphs.graph_document import Node as BaseNode from langchain.graphs.graph_document import Relationship as BaseRelationship from langchain.pydantic_v1 import BaseModel, Field class Property(BaseModel): """A single property consisting of key and value""" key: str = Field(..., description="key") value: str = Field(..., description="value") class Node(BaseNode): properties: Optional[List[Property]] = Field( None, description="List of node properties" ) class Relationship(BaseRelationship): properties: Optional[List[Property]] = Field( None, description="List of relationship properties" ) class KnowledgeGraph(BaseModel): """Generate a knowledge graph with entities and relationships.""" nodes: List[Node] = Field(..., description="List of nodes in the knowledge graph") rels: List[Relationship] = Field( ..., description="List of relationships in the knowledge graph" ) def format_property_key(s: str) -> str: words = s.split() if not words: return s first_word = words[0].lower() capitalized_words = [word.capitalize() for word in words[1:]] return "".join([first_word] + capitalized_words) def props_to_dict(props) -> dict: """Convert properties to a dictionary.""" properties = {} if not props: return properties for p in props: properties[format_property_key(p.key)] = p.value return properties def map_to_base_node(node: Node) -> BaseNode: """Map the KnowledgeGraph Node to the base Node.""" properties = props_to_dict(node.properties) if node.properties else {} # Add name property for better Cypher statement generation properties["name"] = node.id.title() return BaseNode( id=node.id.title(), type=node.type.capitalize(), properties=properties ) def map_to_base_relationship(rel: Relationship) -> BaseRelationship: """Map the KnowledgeGraph Relationship to the base Relationship.""" source = map_to_base_node(rel.source) target = map_to_base_node(rel.target) properties = props_to_dict(rel.properties) if rel.properties else {} return BaseRelationship( source=source, target=target, type=rel.type, properties=properties )