langchain/templates/neo4j-semantic-layer/neo4j_semantic_layer/information_tool.py
Tomaz Bratanic 3e0cd11f51
templates: Add neo4j semantic layer template (#15652)
Co-authored-by: Tomaz Bratanic <tomazbratanic@Tomazs-MacBook-Pro.local>
Co-authored-by: Erick Friis <erick@langchain.dev>
2024-01-09 15:33:44 -08:00

75 lines
2.4 KiB
Python

from typing import Optional, Type
from langchain.callbacks.manager import (
AsyncCallbackManagerForToolRun,
CallbackManagerForToolRun,
)
# Import things that are needed generically
from langchain.pydantic_v1 import BaseModel, Field
from langchain.tools import BaseTool
from neo4j_semantic_layer.utils import get_candidates, graph
description_query = """
MATCH (m:Movie|Person)
WHERE m.title = $candidate OR m.name = $candidate
MATCH (m)-[r:ACTED_IN|DIRECTED|HAS_GENRE]-(t)
WITH m, type(r) as type, collect(coalesce(t.name, t.title)) as names
WITH m, type+": "+reduce(s="", n IN names | s + n + ", ") as types
WITH m, collect(types) as contexts
WITH m, "type:" + labels(m)[0] + "\ntitle: "+ coalesce(m.title, m.name)
+ "\nyear: "+coalesce(m.released,"") +"\n" +
reduce(s="", c in contexts | s + substring(c, 0, size(c)-2) +"\n") as context
RETURN context LIMIT 1
"""
def get_information(entity: str, type: str) -> str:
candidates = get_candidates(entity, type)
if not candidates:
return "No information was found about the movie or person in the database"
elif len(candidates) > 1:
newline = "\n"
return (
"Need additional information, which of these "
f"did you mean: {newline + newline.join(str(d) for d in candidates)}"
)
data = graph.query(
description_query, params={"candidate": candidates[0]["candidate"]}
)
return data[0]["context"]
class InformationInput(BaseModel):
entity: str = Field(description="movie or a person mentioned in the question")
entity_type: str = Field(
description="type of the entity. Available options are 'movie' or 'person'"
)
class InformationTool(BaseTool):
name = "Information"
description = (
"useful for when you need to answer questions about various actors or movies"
)
args_schema: Type[BaseModel] = InformationInput
def _run(
self,
entity: str,
entity_type: str,
run_manager: Optional[CallbackManagerForToolRun] = None,
) -> str:
"""Use the tool."""
return get_information(entity, entity_type)
async def _arun(
self,
entity: str,
entity_type: str,
run_manager: Optional[AsyncCallbackManagerForToolRun] = None,
) -> str:
"""Use the tool asynchronously."""
return get_information(entity, entity_type)